Guidelines for the Clinical Management of Thalassaemia 2nd Edition - English by Thalassaemia International Federation (TIF)

GUIDELINES FOR THE CLINICAL MANAGEMENT OF

THALASSAEMIA 2 REVISED EDITION ND

Dedication

The authors dedicate this book to George, Ahmad, Giovanna, Nicos, Meigui, Sumitra, Christine, Minh-Quan, Hamid, Pranee, Eduard, Karim, and all other patients with thalassaemia, who are not with us any more but whose will and determination to live have inspired researchers and health professionals across the world to promote scientific knowledge and quality care.

It is our fervent hope that this book will serve not only as a manual for promoting clinical management, but also as a tool for improving communication and collaboration amongst all of those, patients, parents, health professionals and others who are striving towards the same goal, the establishment of effective control of thalassaemia and the promotion of equal access to quality health care for every patient with Thalassaemia.

EDITORS AND AUTHORS: Maria-Domenica Cappellini, MD – Professor, Centro Anemie Congenite, Ospedale Maggiore Policlinico IRCCS, University of Milan, Italy Alan Cohen, MD – Professor of Paediatrics, University of Pennsylvania, School of Medicine, USA Androulla Eleftheriou, Ph.D. – Ex-Director of the Virus Reference Laboratory, Ministry of Health Cyprus, Executive Director - Thalassaemia International Federation Antonio Piga, MD – Professor, Dipartimento di Scienze Pediatriche e dell’Adolescenza, Universita degli Studi di Torino, Italy John Porter, MD – Professor, Department of Haematology, University College, London, UK Ali Taher, MD – Professor Medicine - Hematology & Oncology, Department of Internal Medicine, American University of Beirut Medical Center, Beirut Lebanon

AUTHORS OF CHAPTERS: Athanasios Aessopos, MD - Professor of Cardiology, First Department of Internal Medicine, University of Athens - "Laiko" General Hospital, Athens, Greece Emanuel Angelucci, MD - Professor of Haematology, U.O. Ematologia Ospedale Oncologico "Armando Businco", Cagliari, Italy Michael Antoniou, Ph.D. - Division of Medical & Molecular Genetics, GKT School of Medicine, Guy's Hospital, London, UK Ratna Chatterjee, MD – Consultant/Senior Lecturer in Reproductive Health, University College London, London, UK Demetrios Farmakis, MD - First Department of Internal Medicine, University of Athens - "Laiko" General Hospital, Athens, Greece. Susan Perrine, MD - Director of Haemoglobinopathy/Thalassaemia Research Unit, Professor of Paediatrics – Medicine Pharmacology and Experimental Therapeutics Boston, Boston University School of Medicine, Boston, Massachusetts, USA Vicenzo De Sanctis, MD- Professor of Paediatric Endocrinology, Divisione Pediatrica Azienda, Ospedaliera – Archispedale S. Anna, Ferrara, Italy Malcolm John Walker, MD - Consultant Cardiology – Hatter Institute, Cecil Fleming House, University College London Hospital, London, UK

CO-ORDINATING EDITOR: Androulla Eleftheriou, B.Sc., M.Sc., Ph.D., Dipl.MBA

CONTRIBUTORS: Constantina Politis, MD – Associate Professor, Director of the 3rd Reg. Blood Transfusion Centre, 'George Gennimatas' General Hospital, Athens, Greece Ala Sharara, MD – Professor, Director of Division of Gastroenterology- American University of Beirut Medical CenterEndoscopy Unit, Beirut, Lebanon Nicos Skordis, MD - Consultant of Paediatric Endocrinology, Department of Paediatrics, Thalassaemia Centre, Makarios III Hospital, Ministry of Health Cyprus, Nicosia, Cyprus. Ersi Voskaridou, MD - Director of the Thalassaemia Unit and WHO Collaborating Centre, Geniko Laiko Nosokomio Athinon, Greece

ACKNOWLEDGEMENTS: The Thalassaemia International Federation would like to express its most sincere appreciation and gratitude to Dr. Helen Perry – Editor, Dr Michael Angastiniotis - Thalassaemia International Federation, Medical Advisor and Dr. Matheos Demetriades – Thalassaemia International Federation, Projects’ Coordinator for their invaluable contribution to the completion of the book.

Contents Foreword

Introduction

CHAPTER 1

Genetic Basis and Pathophysiology

CHAPTER 2

Blood Transfusion Therapy in ‚-Thalassaemia Major

CHAPTER 3

Iron Overload

CHAPTER 4

Endocrine Complications In Thalassaemia Major

CHAPTER 5

Management of Fertility and Pregnancy in ß-thalassemia

CHAPTER 6

Diagnosis and Management of Osteoporosis in ‚-thalasaemia

CHAPTER 7

The Management of Cardiac Complications in Thalassaemia Major

CHAPTER 8

The Liver in Thalassaemia

CHAPTER 9

106

Infections in Thalassaemia Major

CHAPTER 10

116

Splenectomy in ‚-thalassaemia

CHAPTER 11

121

Thalassaemia Intermedia and HbE

CHAPTER 12

132

Stem Cell Transplantation

CHAPTER 13

136

Alternative Approaches to the Treatment of Thalassaemia

CHAPTER 14

139

Gene Therapy: Current Status and Future Prospects

CHAPTER 15

142

Psychological Support in Thalassaemia

CHAPTER 16

149

General Health Care and Lifestyle in Thalassaemia

CHAPTER 17

155

Organisation and Programming of a Thalassaemia Centre

CHAPTER 18

159

Outline of Diagnostic Dilemmas in Thalassaemia

References

170

Growth Charts

188

Index

192

About Thalassaemia International Federation

198

Foreword

The fight against thalassaemia has entered new and exciting territory, with major advances dramatically improving patient care. At the forefront of that fight, the Thalassaemia International Federation (TIF) remains true to its goal: to secure equal access to quality healthcare for every patient with thalassaemia around the world. This book is a key tool in achieving that goal. Written by some of the world’s leading authorities on haemoglobin disorders, this second revised edition of Guidelines for the Clinical Management of Thalassaemia provides medical professionals with a clear, comprehensive guide to the optimal treatment of thalassaemia, based on scientific evidence, clinical studies and observations. The information provided here has been meticulously compiled by experts fully aware of the many different circumstances in which medical personnel strive to treat patients with thalassaemia. As such, it sets out to provide a full guide to the treatment to which every patient everywhere is entitled, including access to sufficient quantities of safe blood and iron chelation therapy, as well as offering a comprehensive assessment of groundbreaking advances in chelation therapy, other treatment options and the long-awaited final cure, including stem cell transplantation and gene therapy. With the support of member associations, dedicated scientists and healthcare workers, patients, families and friends, TIF focuses on three categories of projects, each contributing to the overall goal of reaching its objectives and achieving its mission: TIF projects aim to promote and support: ñ Awareness about thalassaemia, its prevention and its medical and other care; ñ Research focused on the continuous improvement of medical care and on realising a total cure for thalassaemia, and; ñ Dissemination of the knowledge, experience and expertise of countries with successful control programmes to countries in need. TIF’s activities in achieving the above include: 1. The establishment of new and promotion of existing national patient organisations; 2. ñ ñ ñ ñ ñ

The development of a collaborative network of national and international thalassaemia and other disease-specific patient organisations; medical and scientific communities involved in the field; research institutes and medical centres of excellence; health-related organisations, and; pharmaceutical industries

3. The coordination of or participation in national, regional and international projects contributing to worldwide improvements in: ñ Epidemiology

ñ Medical and other care ñ Social integration and quality of life ñ Extending knowledge of the disease, its prevention and treatment to policy makers, health professionals, patients and parents, and the community at large ñ Securing the rights of every patient for equal access to quality medical care, and ñ The safety and adequacy of blood 4. The establishment of programmes for the continuous education of health professionals, patients and parents, and the community, including: ñ Organisation of local, national, regional European and international workshops, conferences, seminars and meetings. ñ The preparation, publication, translation and free distribution of educational and awarenessraising material. The recent launch of a unique e-MSc in Haemoglobinopathies, offered by University College London (UCL) and part-funded by TIF, is just one example of the scope and ambition of TIF’s educational programme.

TIF’s achievements are the result of voluntary, dedicated work by scientists and medical professionals from around the world, without which TIF’s educational programme, one of its most important tools for the dissemination of knowledge and experience, would never have achieved the level of success it currently enjoys. The authors and all other contributors that have made this book possible deserve particular recognition for their work. The first edition of this book served for many years as the reference text for the treatment of thalassaemia. We are confident that this second edition will make a similar if not greater contribution to efforts to spread existing knowledge and the advances achieved in the last seven years in the field of the clinical management of thalassaemia. Special acknowledgement is also due to a number of other specialists, including Antonio Cao, Vilma Gabutti, Renzo Galanello, Giuseppe Masera, Bernadette Modell, Annuziata di Palma, Calogero Vullo and Beatrix Wonke, who led the way in the early, difficult years, when knowledge on this subject was very limited. They are amongst the pioneers in the promotion of the clinical management of thalassaemia and in the setting out of standards of care to which every patient is entitled. The first edition of the Guidelines for the Clinical Management of Thalassaemia, published in 2000, was the first of its kind to be produced at a time when specialists, patients and parents considered its preparation essential, in view of the rapid achievements in the treatment of thalassaemia. This new, fully updated, second edition is a timely response to the many further advances that have been made since then. As a response to the rapid medical advancements achieved after 2000 in the field of management of thalassaemia, a new second edition of the Guidelines, Thalassaemia was published by TIF in

December 2007 offering an invaluable tool to medical staff involved in the treatment of thalassaemia. Only a year after its publication and distribution across the world, TIF ran out of stock and in order to have a timely response to the needs of health professionals involved in the treatment of thalassaemia, TIF in collaboration with the main authors and editors of the book have published this second revised edition in December 2008. Governments, National Health Authorities, Thalassaemia Centres and individual health professionals in the field are strongly encouraged to follow the recommendations of the panel of experts as presented in this book.

At the same time, it is extremely important that the prevention of thalassaemia receives similar attention. While outside the scope of this book, the prevention of thalassaemia remains a crucial objective for TIF. Unless new births of affected children are prevented or minimized, even the best updated treatment programmes will eventually collapse, unable to provide for an ever-increasing number of patients. In this context, the development of national prevention programmes is at the heart of TIFâ&#x20AC;&#x2122;s activities. TIF, based on its long-time experience, can offer considerable support to countries, including detailed advice on the structure of, and challenges to implementing, such programmes. On behalf of the Board of Directors of TIF I would like to once again extend our deepest gratitude to the experts who have dedicated work, time and effort in producing this second revised edition of Guidelines to the Clinical Management of Thalassaemia. Last but by no means least, I would like to express our most sincere appreciation to the Non-Communicable Diseases Genetics Department of the World Health Organisation (WHO), with which TIF has been collaborating on an official basis since 1996, and whose support and guidance in promoting our mission have been multi-faceted and invaluable.

Panos Englezos TIF President

Introduction

Haemoglobin (Hb) disorders are hereditary, genetic diseases consisting mainly of sickle cell disease and the thalassaemias, which account for a great proportion of births affected by a genetic disease. The thalassaemias are a heterogeneous group of the haemoglobin disorders in which the production of normal haemoglobin is partly or completely suppressed as a result of the defective synthesis of one or more globin chains. Several types of thalassaemia have been described and named according to the affected globin-chain, the most common types of clinical importance being ·-, ‚‰- and ·-thalassaemia.

Haemoglobin disorders are thought to have originated in countries where malaria was or is endemic—areas to which it was for many years believed such disorders were confined. Sub-Saharan Africa accounts for more than 70% of births affected by sickle cell disorders every year, with the remainder occurring at various rates (from low to high) in other parts of the world. Thalassaemia, including HbE, is more prevalent in the Mediterranean basin, the Middle East, Southern and Eastern Asia, the South Pacific and South China, with reported carrier rates ranging from 2% to 25%. Although reliable data are still lacking for many regions of the world, recent data indicate that about 7% of the world’s population is a carrier of a haemoglobin disorder, and that 300,000500,000 children are born each year with the severe homozygous states of these diseases. (World Bank 2006, report of a joint WHO-March of Dime meeting 2006) It is now well recognised that Hb disorders are not confined to any particular region, occurring widely across the world and constituting a global public health problem. Hb disorders have spread through the migration of populations from endemic areas to countries where their prevalence in indigenous populations had been extremely low. Such countries include the USA, Canada, Australia, South America, the United Kingdom and France, where migration occurred up to a century ago and where large ethnic minority groups are now entering their fourth and even fifth generation. More recent migration movements from highly endemic countries have been to Northern and Western Europe, where the prevalence of Hb disorders in the indigenous population is very low, including Germany, Belgium, the Netherlands and, more recently, Scandinavia. These changes have challenged health professionals and policy-makers throughout the region in providing equitable access to quality services for the prevention and treatment of Hb disorders. In some regions, such as Scandinavia, to which there is currently large-scale migration, the proportion of births in ‘at-risk groups’ is predictive of the future genetic make-up of the population, as has been the case in some of the countries mentioned above, where large scale migration from affected countries had occurred much earlier.

Carrier prevalence will clearly continue to rise in Northern and Western Europe, even in the absence of further migration, as a result of reproduction and inter-community marriages, and Hb disorders are likely to become the leading recessive disorder throughout the region, posing a serious public health problem. Clearly, the earlier classification of endemic and non-endemic countries for Hb disorders is no longer relevant. However, effectively addressing the control of these disorders in these countries will require considerable work, financial backing and certainly political commitment. The main difficulty is that the populations of these countries are not homogeneous, as was the case in the Mediterranean countries where the earliest control programmes were successfully established. Some countries in Europe, such as the United Kingdom and France, have already accumulated considerable experience and knowledge in the most cost-effective and practical ways of intervention to address this highly important public health problem. Recognition of the problem in Northern and Western Europe has raised concerns and stirred up interest amongst national and EU health policy-makers who, in addition to and complementary to the work of World Health Organisation (WHO), which was traditionally involved in the promotion of control programmes for Hb disorders, have already taken significant steps in the context of their agenda on rare diseases. Unlike affected countries of the developing world, these countries already have strong health care infrastructure and systems in place, and the resources and quality health services required. The European countries need to address ethnic minorities, which are widely scattered geographically, and to raise strong health professional and patient/parent awarenessâ&#x20AC;&#x201D;tasks that are essential in the promotion of effective control programmes. Recent improvements in the resources and health care structures of Eastern European countries such as Bulgaria and Romania have contributed to a greater recognition of the importance of developing and implementing control systems for Hb disorders occurring in the indigenous population, which in some regions can reach very high carrier levels. Southern European countries with Hb disorders occurring in the indigenous population, albeit at considerably lower prevalence rates, include Portugal and Spainâ&#x20AC;&#x201D;countries that are, however, able to respond effectively to public health requirements and to adopt effective policies. Low prevalence European countries where haemoglobinopathies have not yet penetrated to a significant degree through migration include Poland, Hungary and the Czech Republic, although these, along with Spain and Portugal, constitute potential targets for increasing migration. Albania is a separate example, having higher prevalence rates of Hb disorders than the rest of the Balkan countries in the indigenous population with carriers and affected individuals widely scattered across the country. Although appropriate services are still largely underdeveloped, significant progress has been achieved during the last few years, especially in the area of clinical management. Unfortunately data on the epidemiology and status of control programmes in Russia remains scanty.

In lower and middle-income countries on the other side of the world, where haemoglobin disorders are most prevalent in the indigenous population, 50-80% of children with sickle cell disease and a significant number of children with ‚-thalassaemia die each year—undiagnosed or misdiagnosed, sub-optimally treated or not treated at all. There is an urgent need to bridge this wide gap until every patient in every part of the world has equal access to quality medical care. An essential means of doing so is through global collaboration on Hb disorders, enabling all countries to benefit from each other’s experience. Health authorities need to recognise Hb disorders as a significant threat to public health—one that deserves the development and implementation of national policies for treatment and prevention. The instruments required to support such policies include:

ñ ñ ñ ñ

Standards and guidelines for laboratory services National guidelines for the management of thalassaemia Epidemiological information and surveillance Establishment of an educational programme for health professionals, patients, parents and the community

It is evident that all countries would benefit from the sharing of experience and expertise. The difficulties encountered in service development for haemoglobin disorders apply equally to many other inherited disorders. Professionals and support groups alike would benefit from forming wider partnerships with similar groups representing other disorders. It is hoped that this book will offer valuablel information to all medical professionals involved in the treatment of patients with thalassaemia. It includes updated information on new approaches for more effective, safe and less laborious treatment, and an overview of the progress achieved to date towards a total cure for thalassaemia, using methods such as gene therapy and stem cell transplantation. Until the final goal of a complete cure for thalassaemia is found, it is the obligation of national health authorities and health professionals to provide, and the right of patients to receive, the most complete and up-to-date systems of treatment available. We hope that these guidelines, which constitute the authors’ consensus on the most effective treatment of ‚-thalassaemia major, will prove an indispensable tool for health professionals involved in this field. Androulla Eleftheriou, B.Sc., M.Sc., Ph.D., Dipl.MBA TIF Executive Director Coordinating Editor

Genetic Basis and Pathophysiology

structure of the globin chains is coded by genes contained in the DNA of chromosomes 16 (the · gene cluster) and 11 (the ‚ gene cluster). Flanking the structural genes, i.e. in front (on the 5’ side of the DNA sequence, “upstream”) and following them (on the 3’ side of the DNA sequence, “downstream”), lie several nucleotide sequences which have a “regulatory” role, i.e. they determine which gene is to be turned on and which off, as well as how efficient its expression will be. In adult life, most of the globin synthesis occurs in the erythroblasts in the bone marrow. Haemoglobin must have the correct structure and be trimmed in such a way that the number of ·-chains precisely matches that of the ‚-chains. When the above conditions are not met, the result is a complete or partial defect in one or both “allelic” globin genes.

Haemoglobin Types Oxygen is transported from the lungs to the tissues by a highly specialised protein molecule, haemoglobin, which is located in the red cells of the blood. Each red blood cell contains approximately 300 million molecules of this protein, totalling about 30 picograms in weight per cell. Each molecule of haemoglobin is formed by two pairs of identical sub-units, the globin chains, which are named with letters of the Greek alphabet and belong to two groups: the ·-globin cluster, comprising the ˙- and ·-globin chains, and the ‚-globin cluster, comprising the globin chains Â, Á, ‚ and ‰. The globin chains appear sequentially during ontogeny and, after pairing, form the following four major types of haemoglobin: a) “embryonic” haemoglobins, which are detectable from the 3rd to the 10th week of gestation and represent ˙2Â2, ·2Â2 and ˙2Á2 tetramers; b) “fetal” haemoglobin (HbF ·2Á2), which constitutes the predominant oxygen carrier during pregnancy ; c) “adult” haemoglobin (HbA ·2‚2), which replaces HbF shortly after birth, and; d) a minor adult component, HbA2 (·2‰2).

The Thalassaemias: Definitions and Worldwide Distribution The term “thalassaemia” refers to a group of blood diseases characterised by decreased synthesis of one of the two types of polypeptide chains (· or ‚) that form the normal adult human haemoglobin molecule (HbA, ·2‚2), resulting in decreased filling of the red cells with haemoglobin, and anaemia.

Under normal conditions, the red cells of the adult human contain approximately 98% HbA, 2.0% HbA2 and traces of HbF.

Globin Genes and Globin Synthesis The globin chains have an extremely precise structure, ensuring their prompt loading with oxygen in the lung alveoli and its controlled gradual delivery into the tissues. The precise

Depending on which of the genes the defect occurs and the corresponding effect on the

alterations of their red cells, an increased level of HbA2, and a low ‚/·- globin chain ratio on biosynthesis, which is occasionally associated with low normal or slightly subnormal haemoglobin levels. Under normal circumstances, the thalassaemia trait is not related to any significant clinical effects, mainly because the activity of the normal ‚ gene on the allelic chromosome makes enough stable globin. In contrast, inheritance of two defective ‚-globin genes results in a wide spectrum of clinical conditions, ranging from transfusion dependence (thalassaemia major) to mild or moderate anaemia (thalassaemia intermedia). Molecular studies may reveal a large array of abnormalities underlying the above phenotypes and may assist in their identification.

production of globin chains, ·-thalassaemia or ‚-thalassaemia results. The present book mainly addresses the latter group of thalassaemias, which are now recognised to occur widely across the world well beyond the countries where these were originally thought to be endemic i.e. countries around the Mediterranean Basin, the Middle East, Trans-Caucasus and India for ‚- and the Far East for ·-thalassaemia (see Figure 1).

‚-Thalassaemia Phenotypic heterogeneity As a rule, heterozygous carriers of ‚thalassaemia (one affected allele), display a low mean cellular haemoglobin (MCH), low mean cell volume (MCV), mild morphological

CELL TYPE SITE OF ERYTHROPOIESIS

PERCENTAGE OF TOTAL GLOBIN SYNTHESIS

Figure 1: Globin synthesis at various stages of embryonic and fetal development

below outlines the pathophysiology of ‚thalassaemia and describes the chain of events following globin chain imbalance and the accumulation of excess ·-chains – that is, ineffective erythropoiesis leading to anaemia, bone marrow expansion, skeletal deformities and increased GI iron absorption.

Pathophysiology of ‚-thalassaemia Advances in the management of thalassaemia were achieved only after the pathophysiology of the disease was elucidated and clearly understood by the scientific and medical community involved in the field. Figure 2

The degree of globin chain imbalance is determined by the nature of the mutation of

PATHOPHYSIOLOGY OF ‚-THALASSAEMIA MAJOR

Figure 2: Effects of excess production of free ·-globin chains

Table 1 includes the common types of ‚-thalassaemia mutations according to ethnic distribution and severity. A more comprehensive list of ‚ mutations can be found on the internet at

the ‚-gene. ‚o refers to the complete absence of production of ‚-globin on the affected allele. ‚+ refers to alleles with some residual production of ‚-globin (around 10%). In ‚++ the reduction in ‚-globin production is very mild. More than 200 thalassaemic mutations have been reported to date.

http://globin.cse.psu.edu/globin/html/huisman .

Population

‚-gene Mutation

Severity

Indian

-619 del

‚Ô

Mediterranean

-101

‚++

Black

-88

‚++

Mediterranean; African

-87

‚++

Japanese

-31

‚++

African

-29

‚++

Southeast Asian

-28

‚++

Black

-26

‚++

Mediterranean; Asian Indian

IVS1-nt1

‚o

Mediterranean; Asian Indian

IVS1-nt5

‚o

Mediterranean

πøS1-nt6

‚+/++

Mediterranean

IVS1-nt110

‚+

Chinese

IVS2-nt654

‚+

Mediterranean

IVS2-nt745

‚+

Mediterranean

codon 39

‚o

Mediterranean

codon 5

‚o

Mediterranean; African-American

codon 6

‚o

Southeast Asian

codons 41/42

‚o

African-American

AATAAA to AACAAA

‚++

Mediterranean

AATAAA to AATGAA

‚++

Mediterranean

Hb Knossos

‚++

Southeast Asian

HbE

‚++

Table 1: Common types of ‚-thalassaemia, their severity and ethnic distribution

Beta structural haemoglobin variants relevant to thalassaemia management

are variable in severity— ranging from those characterising thalassaemia intermedia to those described for severe transfusiondependent thalassaemia major. The reasons for this variability have only partially been defined, since patients with seemingly identical genotypes present with clinical manifestations very different in severity.

Haemoglobin E disorder is the most common structural variant resembling thalassaemia desorders (see relevant Chapter 11: Thalassaemia Intermedia). HbE results from a mutation (G➔A) at codon 26 of the ‚-globin gene causing the substitution of lysine for glutamic acid – a mutation that results in a qualitative and quantitative ‚-globin gene defect since it is related to the activation of a cryptic splice site at codon 24-25, leading to an alternative splicing pathway. The overall result is the production of reduced amounts of the variant haemoglobin (HbE).

Hb Lepore is another structural ‚ variant resulting from a fusion of the ‰ and ‚ globin genes. The homozygous state of Hb Lepore can result in moderate to severe transfusiondependent ‚-thalassaemia syndromes. Haemoglobin S disorders: HbS, the most common haemoglobin variant in the world, results from a substitution of valine for glutamic acid at position 6 of the ‚-globin chain. The interaction of ‚-thalassaemia with HbS results in a syndrome that most closely resembles the sickling disorders, which typically do not require lifelong transfusions and are not consequently associated with iron overload. As for thalassaemia, Guidelines for the management of sickle cell disorders have been formulated in recent years and a useful web-site for more information is: http://www.nhlbi.nih.gov/health/prof/blood/ sickle/sick-mt.htm.

HbE is the most common abnormal haemoglobin in South East Asia, with a carrier frequency of more than 50% in some regions. It is also prevalent in parts of the Indian subcontinent, including Bangladesh. Heterozygotes for HbE are clinically normal and manifest with 25-30% of HbE on electrophoresis and with only minimal changes in red blood cell indices. Homozygotes for HbE are clinically silent and may be only mildly anaemic. On microscopic examination, the peripheral blood smear demonstrates microcytosis with 20-80% of target red cells, while Hb electrophoresis shows 85-95% of HbE and 5-10% of HbF.

·-thalassaemia ·-thalassaemias are inherited disorders characterised by reduced or suppressed production of ·-globin chains. The human ·globin genes are duplicated and located in the telomeric end of the short arm of chromosome 16. ·-thalassaemia is caused

HbE/‚-thalassaemia constitutes the most common combination of ‚-thalassaemia with a structural variant, most prevalent in South East Asia. The related clinical manifestations

crisis, mainly in response to oxidant drugs and infections.

most commonly by deletions of large DNA fragments that involve one or both ·-globin genes. Silent carrier state: The presence of a single ·-globin gene deletion results in the silent carrier state occurring widely across the world.

Other relevant structural variants include Hb Constant Spring, characterised by ineffective synthesis of a-globin chains, resulting from a defect on the relevant gene that causes their elongation. This mutation is found primarily in Asia and its co-inheritance with the deletion of two ·-genes results in a severe form of HbH disease.

·-thalassaemia trait is characterised by the presence of two residual functional agenes and is not related to any serious clinical or laboratory findings:

Hb Bart’s hydrops fetalis, the most severe clinical manifestation of ·-thalassaemia, is generally associated with the absence of all four ·-globin genes and death in utero. Absence of ·-globin genes in the “cis” position on the same chromosome (·Ôthalassaemia) is common in South East Asia, while it is rare in the Mediterranean area and even rarer in Africa.

Mild anaemia and microcytosis. Deletions or abnormalities of three globin genes result in HbH disease, usually characterised by a moderate haemolytic anaemia, splenomegaly and acute haemolytic

With permition from the Source: March of Dimes: Global Report 2006

Blood Transfusion Therapy in ‚-Thalassaemia Major

relevant laws and taking into account national needs, resources and prevalence of infectious agents, should safeguard the quality of blood transfusion services. Blood donation practices, donor selection (e.g., through questionnaire) and product screening constitute some of the most important strategies that contribute to the safety and adequacy of blood. For more information on EU directives visit: http://europa.eu.int and http://europa.eu.int /consus/health/index_en.html. On recommendations of the Council of Europe visit http://www.coe.int, while on WHO guidelines and American Standards visit www.who.int/bloodsafety/gcbs/structure/en/ and http://www.aabb.org/content, respectively. Other sites are also available should the reader require to obtain more information.

Goals of Blood Transfusion Therapy Appropriate goals of transfusion therapy and optimal safety of transfused blood are the key concepts in the protocol for routine administration of red blood cells to patients with thalassaemia. The major goals are: ñ Maintenance of red cell viability and function during storage, to ensure sufficient transport of oxygen; ñ Use of donor erythrocytes with a normal recovery and half-life in the recipient; ñ Achievement of appropriate haemoglobin level, and; ñ Avoidance of adverse reactions, including transmission of infectious agents.

Quality and Adequacy of Blood

Transfusion Therapy in Thalassaemia

To safeguard the health of the transfusion recipient, including patients with thalassaemia, blood should be obtained from carefully selected regular voluntary, non-remunerated donors and should be collected, processed, stored and distributed, in the context of dedicated, quality assured national blood transfusion centres.

This chapter will address five of the most common questions related to the transfusion therapy of patients with thalassaemia major: (i)

When to initiate transfusion therapy and whom to transfuse; (ii) How blood is processed for effective and safe transfusion therapy in thalassaemia major; (iii) Is there an optimal haemoglobin (Hb) level for effective transfusion; (iv) Do transfusion requirements affect the success of iron chelation therapy; (v) What are the most serious transfusion related (TR) reactions (common and less frequent);

Nationally developed legislation-based on EU, Council of Europe, North American, World Health Organisation (WHO) or other international directives, recommendations or

For deciding whom to transfuse, the following should be included in the investigations:

Recommended blood product

(i)

Patients with â&#x20AC;&#x161;-thalassaemia major should receive leucoreduced packed red blood cells with a minimum haemoglobin content of 40g.

Confirmed laboratory diagnosis of thalassaemia major; (ii) Laboratory criteria: Hb < 7g/dl on 2 occasions, > 2 weeks apart (excluding all other contributory causes such as infections) or (iii) Laboratory and clinical criteria, including: - Hb > 7g/dl with: - Facial changes - Poor growth - Fractures, and - Extramedullary haematopoiesis

Reduction to 1 X 106 or less leucocytes per unit (mean counts as low as 0.05 x 106 are achievable) (Council of Europe, RE 2006) is considered the critical threshold for eliminating adverse reactions attributed to contaminating white cells (see Table 1, below) and for preventing platelet alloimmunisation.

REACTIONS

CAUSATIVE AGENTS

Febrile non-haemolytic transfusion

HLA-antibodies in patients, cytokines

reactions (FNHTR)

produced by donor leucocytes

HLA- alloimmunisation of recipients

HLA antigens on donor leucocytes

Transfusion-transmitted infections

Cell-associated infectious agents

Graft-versus-Host-Disease (GVHD)

Donor T-lymphocytes

[Morell A, ZLB Central Laboratory Swiss Red Cross, Bern Switzerland, 2000. Pathogen inactivation of labile blood products] Table 1: Contaminating Leucocytes as pathogens: Some adverse effects of Leucocytes in labile blood products.

Methods for leucoreduction include:

immunoglobulin A (IgA) deficiency, in which the recipient’s preformed antibody to IgA may result in an anaphylactic reaction. Washing usually does not result in adequate leucocyte reduction and should not be used as a substitute for leucoreduction. Instead, washing should be used in conjunction with filtration. In addition, washing of red cell units may remove some erythrocytes from the transfusion product, and it is therefore valuable to monitor post-transfusion haemoglobin levels to ensure attainment of the targeted Hb level.

ñ Pre-storage filtration of whole blood is the preferred method for leucoreduction. The delay in filtration (4-8 hours) may allow some phagocytosis of bacteria (e.g. Yersinia enterocolitica) (Buchholz, 1992). This method of leucocyte removal offers high efficiency filtration and provides consistently low residual leucocytes in the processed red cells and high red cell recovery. Packed red cells are obtained by centrifugation of the leucoreduced whole blood.

Frozen (or cryopreserved) red cells is the component derived from whole blood in which red cells are frozen, preferably within 7 days of collection, using a cryopreservant and stored at -60oC to -80oC or below, based on the method used. These are used to maintain a supply of rare donor units for certain patients who have unusual red cell antibodies or who are missing common red cell antigens. The Council of Europe is promoting an international network of rare blood donor units and may be contacted as follows: Council of Europe – Point I F67075 Strasbourg Cedex France Tel: +33 3 88 41 2000 Fax: +33 3 88 41 2781 Email: point_i@coe.fr Internet: www.coe.fr/index.asp

ñ Pre-transfusion, laboratory filtration refers to the filtration at the blood bank laboratory of packed red cells, prepared from donor whole blood. ñ Bedside filtration refers to the packed red cell unit which is filtered at the bedside, at the time of transfusion. This method, although equally sensitive to those above, may not allow optimal quality control because the techniques used for bedside filtration may be highly variable.

Blood products for special patient populations

Red cells obtained by donor apheresis: This method whereby two units

Washed red cells may be beneficial for patients with thalassaemia who have repeated severe allergic transfusion reactions. Saline washing of the donor product removes plasma proteins that constitute the target of antibodies in the recipient. Other clinical states that may require washed red cell products include

of red cells are collected from the same donor for transfusion of one patient is associated with reduction of donor exposures and consequently to a decreased risk (i) of transmission of infections, and (ii) of developing alloimmunisation and other transfusion related complications.

the additive solution a suitable osmotic strength. Thus the introduction of additives such as AS-1, AS-3, AS-5 (see Table 2b) has permitted considerably longer storage of red cells for up to 42 days.

Neocyte or young red cell transfusion may modestly reduce blood requirements (Spanos, 1996). However, patients are exposed to a higher number of donors, with a consequent increase in cost, risk of transmission of infections, and risk of developing alloantibodies.

The maximum duration of storage (expiry date) as noted on each unit varies with the type of preparation (concentration of cells, formula of anticoagulant, use of additive suspension fluid, etc) and should be determined for each type on the basis of achieving a mean 24 hours post-transfusion survival of no less than 75% of the transfused red cells.

Storage of donor red cell units The anticoagulant preservative solutions used in blood collection (see Table 2a) have been developed to prevent coagulation and to permit storage of red cells for a certain period of time. All of these solutions contain sodium citrate, citric acid and glucose, some of them may also contain adenine, guanosine and phosphate (e.g., CPD-A).

The haemoglobin oxygen release function (which is extremely important in thalassaemia major) is impaired during storage due to progressive loss of 2, 3-biphosphoglycerate (2, 3-BPG, previously known as 2, 3diphosphoglycerate, DPG). Although, the storage time of whole blood in CPDA-1 for example is 35 days (CoE Re 2006), after 10 days of storage all 2, 3 â&#x20AC;&#x201C; BPG is lost (CoE Re 2006). In the case of additives such as the ones mentioned above (see Table 2b), although storage times up to 42 days are advocated and high levels of ATP are maintained up to the 28th day of storage, 2, 3-BPG and P50 values may not be fully maintained even for this length of time. In addition, information about the red cell halflife in the recipient after prolonged storage of donor blood is limited. Taking into consideration all the above and in view of the fact that in thalassaemia major, decreased recovery and a shortened red cell half-life may increase transfusion requirements and

When red cell concentrates are prepared, a considerable part of the glucose and adenine is removed with the plasma. If not compensated for in other ways, sufficient viability of the red cells can only be maintained if the cells are not overconcentrated. Normal CPD-adenine red cell concentrate should therefore not have a haematocrit (Hct) above 0.70 on average (CoE Re 2006). Newly developed additive solutions, however, allow maintenance of red cell viability even if more than 90% of the plasma is removed, as they contain considerably higher levels of the necessary nutrients (see Table 2b). The use of glucose and adenine is necessary for the maintenance of red blood cell posttransfusion viability, phosphate may be used to enhance glycolysis, and other substances (e.g.; mannitol, citrate) may be used to prevent in vitro haemolysis. Sodium chloride or di-sodium phosphate may be used to give

as a consequence the rate of transfusional iron loading. the current practice is to use red cells stored in additive solutions for less than two weeks, and in CPD-A for even less days â&#x20AC;&#x201C; as fresh as possible. In patients with cardiac disease and in small children, particular attention should be paid to the

increased volume resulting from additive solutions. In general, for all patients, the lower haematocrit of red cell units containing newer additive solutions should be taken into consideration when calculating the annual rate of transfusional iron loading (see Tables 2a & 2b).

ACD-A

CPD

CP2D

CPDA-1

Trisodium citrate

22.00

26.30

Citric acid

8.0

3.27

Dextrose

24.50

25.50

51.10

31.90

2.22

Monobasic sodium phosphate Adenine

0.275

[Source: Brecker M, ed Technical Manul, 14TH ed Bethesda, MD: American Association of Blood Banks, 2003: 162] Table 2a: Content of anticoagulant-preservative solutions (g/L)

AS-1 (Adsol)

AS-3 (Nutricell)

AS-5 (Optisol)

Dextrose

2,200

1,100

900

Adenine

Monobasic sodium phosphate

276

Mannitol

750

525

Sodium Chloride

154.00

70.00

15.00

Sodium Citrate

588

Citric acid

[Source: Brecker M, ed Technical Manul, 14TH ed Bethesda, MD: American Association of Blood Banks, 2003: 183] Table 2b:Content of additive solutions (mg/100mL)

Compatibility testing

単

Development of one or more specific red cell antibodies (alloimmunisation) is a common complication of chronic transfusion therapy (Spanos, 1990; Singer, 2000). Thus it is important to monitor patients carefully for the development of new antibodies and to eliminate donors with the corresponding antigens. Anti-E, anti-C and anti-Kell alloantibodies are the most common. However, 5-10% of patients present with alloantibodies against rare erythrocyte antigens or with warm or cold antibodies of unidentified specificity.

If new antibodies appear, they must be identified so that in future blood lacking the corresponding antigen(s) can be used. A complete and detailed record of antigen typing, red cell antibodies and transfusion reactions should be maintained for each patient, and should be readily available when and if the patient is transfused at a different centre. Transfusion of blood from first-degree relatives should be avoided because of the risk of developing antibodies that might adversely affect the outcome of a later stem cell transplant.

It is recommended that: 単

単

Before each transfusion it is necessary to perform a full crossmatch and screen for new antibodies.

Before embarking on transfusion therapy, patients should have extended red cell antigen typing that includes at least C, c, E, e and Kell, in order to help identify and characterise antibodies in case of later immunisation;

Transfusion programmes The recommended treatment for thalassaemia major involves lifelong regular blood transfusions, usually administered every two to five weeks, to maintain the pretransfusion haemoglobin level above 9-10.5 g/dl.

All patients with thalassaemia should be transfused with ABO and Rh(D) compatible blood.

This transfusion regimen promotes normal growth, allows normal physical activities, adequately suppresses bone marrow activity in most patients, and minimises transfusional iron accumulation (Cazzola, 1995 and 1997). A higher target pre-transfusion haemoglobin level of 11-12 g/dl may be appropriate for patients with heart disease or other medical

In addition, the use of blood that is also matched for the C, E and Kell antigens is highly recommended in order to avoid alloimmunisation against these antigens. Some centres use even more extended antigen matching.

conditions and for those patients who do not achieve adequate suppression of bone marrow activity at the lower haemoglobin level. Although shorter intervals between transfusions may reduce overall blood requirements, the choice of interval must take into account other factors such as the patientâ&#x20AC;&#x2122;s work/school schedule and other lifestyle issues.

(Michail-Merianou, 1987; Spanos, 1990; see Table 3). Presence of alloantibodies and autoantibodies (see below) may severely compromise transfusion therapy in patients with thalassaemia intermedia, for example, who receive their first transfusions in adolescence or later. Recommendations regarding the volume of transfused red cells are complicated by the use of different anticoagulant-preservatives and additive solutions. For CPD-A units with a haematocrit of approximately 75%, the volume per transfusion is usually 10-15 ml/kg, administered over 3-4 hours. Units with additive solutions may have lower haematocrits in the range of 60-70%, and consequently larger volumes with a higher haematocrit level are needed to administer the same red cell mass (see Table 4). For most patients, it is usually easier to avoid these differences in red cell concentration by ordering a certain number of units (e.g. one or two) rather than a particular volume of blood. Younger children may require a fraction of a unit to avoid under- or overtransfusion. Patients with cardiac failure or very low initial haemoglobin levels should receive smaller amounts of red cells at slower rates of infusion.

The decision to initiate lifelong transfusion therapy should be based on a definitive diagnosis of â&#x20AC;&#x161;-homozygous thalassaemia. This diagnosis should take into account the molecular defect, the severity of anaemia on repeated measurements, the level of ineffective erythropoiesis, and clinical criteria such as failure to thrive or bone changes. The initiation of regular transfusion therapy for severe thalassaemia usually occurs in the first two years of life. Some patients with milder forms of thalassaemia who only need sporadic transfusions in the first two decades of life may later need regular transfusions because of a falling haemoglobin level or the development of serious complications (see Chapter 11: Thalassaemia Intermedia and HbE). The risk of alloimmunisation appears to be greater in patients who begin transfusion therapy after the first few years of life Age at First Transfusion Alloimmunisation Rate < 1 year old

7.7%

> 1 year old

27.9%

[Machail-Merianou et al, 1987]

Age at First Transfusion Alloimmunisation Rate < 3 years old

20.9%

> 3 years old

47.5%

Table 3: Age and alloimmunisation in Thalassaemia

[Spanos et al, 1990]

Haematocrit of Donor Red Cells

Target Increase in Haemoglobin Level

50%

60%

75%

80%

1 g/dl

4.2 ml/kg

3.5 ml/kg

2.8 ml/kg

2.6 ml/kg

2 g/dl

8.4 ml/kg

7.0 ml/kg

5.6 ml/kg

5.2 ml/kg

3 g/dl

12.6 ml/kg

10.5 ml/kg

8.4 ml/kg

7.8 ml/kg

4 g/dl

16.8 ml/kg

14.0 ml/kg

11.2 ml/kg 10.4 ml/kg

As an example, to raise the haemoglobin level by 4g/dl in a patient weighing 40kg and receiving AS-1 blood with a haematocrit of 60% would require 560ml. This calculation assumes a blood volume of 70ml/kg of body weight.

Table 4: Guidelines for choosing how much blood to transfuse

The post-transfusion Hb should not be greater than 14-15g/dl and should be monitored occasionally to allow assessment of the rate of fall in the haemoglobin level between transfusions in evaluating the effects of changes in the transfusion regimen, the degree of hypersplenism, or unexplained changes in response to transfusion.

A careful record of transfused blood should be maintained for each patient, including the volume or weight of the administered units, the haematocrit of the units or the average haematocrit of units with similar anticoagulantpreservative solutions, and the patientâ&#x20AC;&#x2122;s weight. With this information, it is possible to calculate the annual blood requirements as volume of transfused blood and pure red cells (haematocrit 100%) per kg of body weight.

Although erythrocytapheresis, or automated red cell exchange, has been shown to reduce net blood requirements and thus the rate of transfusional iron loading (Berdoukas, 1986; Friedman, 2003], its use may be limited due to a two- to three-fold increase in donor blood utilisation, increased (i) costs, (ii) risk of transmission of infections and (iii) development of alloimmunisation.

The latter (RBC at 100% ht) when multiplied with 1.08, the estimated amount of iron per ml of RBC (see Chapter 3: Iron Load and Iron Chelation) yields an approximate value for

the amount of transfusional iron that the patient receives per kilogram of body weight in a year. Figure 1 shows a detailed example of how the daily rate of iron loading (mg/kg/day) is calculated and Table 5 shows the relationship between the annual transfusion requirements and the daily rate of iron loading at two common haematocrits

for donor blood. The rate of transfusional iron loading may be very important in choosing the appropriate dose of an iron chelator. For example, the recommended dose of the chelator deferasirox is based in part on the daily or annual rate of transfusional iron loading.

Patient weight: 40kg Transfusion amount and schedule: 600ml every 4 weeks. Average haematocrit of transfused red cells: 60% Annual blood requirement: 13 transfusions x 600ml/40kg = 195ml/kg Annual pure red cell requirement: 195ml/kg/yr x 60% (average haematocrit) = 117ml/kg/yr Annual transfusional iron loading: 117ml/kg/yr of pure red cells x 1.08mg iron per ml pure red cells = 126mg iron Daily transfusional iron loading: 126mg iron/yr/365 days = 0.34mg/kg

Figure 1: Calculation of annual blood requirements and transfusional iron loading.

Annual Blood Requirement (Haematocrit 60%)

Annual Blood Requirement (Haematocrit 75%)

100 – 150 ml/kg

80 – 120 ml/kg

150 – 200 ml/kg

Volume of Pure RBCs/kg (Haematocrit 100%)

Daily Iron Loading

60 – 90 ml/kg

0.18 – 0.27 mg/kg

120 – 160 ml/kg

90 – 120 ml/kg

0.27 – 0.36 mg/kg

200 – 250 ml/kg

160 – 200 ml/kg

120 – 150 ml/kg

0.36 – 0.44 mg/kg

250 – 300 ml/kg

200 – 240 ml/kg

150 – 180 ml/kg

0.44 – 0.53 mg/kg

Table 5: Relationship between annual blood requirements and rate of daily iron loading.

Knowing the annual transfusion requirements is also valuable in identifying changes that may constitute important evidence of hypersplenism or accelerated destruction of donor red cells.

Adverse reactions Blood transfusion exposes the patient to a variety of risks. Thus, it is vital to continue to improve blood safety and to find ways of reducing transfusion requirements and the number of donor exposures.

Specific guidelines for consideration of splenectomy in the presence of increasing transfusion requirements are difficult to establish because of a lack of information on the haematocrit levels of the transfused blood in earlier recommendations and uncertainty with regard to long-term consequences of splenectomy, including sepsis and thrombosis. Moreover, the decision to proceed to splenectomy must take into consideration the individual patientâ&#x20AC;&#x2122;s ability to control iron stores at a given level of transfusional iron loading. Nevertheless, as the annual transfusion requirements rise above 200ml/kg/yr of pure red cells, splenectomy should be considered as a potential strategy to reduce the rate of iron loading.

Adverse events (see Table 6) associated with transfusion include: Ăą Nonhaemolytic febrile transfusion reactions: These were common in past decades, but have been dramatically reduced by leucoreduction, especially pre-storage leucoreduction, which sharply reduces cytokine accumulation and leucocyte alloimmunisation. In the absence of effective leucoreduction, patients experiencing such reactions should be given antipyretics before their transfusions. Since fever may accompany a haemolytic transfusion reaction or the administration of a unit with bacterial

ACUTE

FREQUENCY

DELAYED

FREQUENCY

Haemolytic (Intravascular)

1/25,000

Alloimmune

1/100

Anaphylactic

1/50,000

Haemolytic (Extravascular)

1/ 2,500

Febrile non-haemolytic

1/100

Graft Vs Host Disease

Rare

Allergic (Urticarial)

1/100

TR Acute Lung Injury

1/10,000

Table 6: Broad categorisation of immune-mediated transfusion related (TR) reactions and reported frequencies

adherence to standard protocols for screening for antibodies and carrying out the necessary full crossmatching of donor units and (4) use of multiple patient identifiers before transfusing the blood. In many transfusion units, two staff members check the identification of the unit and the recipient prior to beginning the transfusion.

contamination, these causes should always be considered in a patient who develops fever during administration of red cells. 単 Allergic reactions are usually due to plasma proteins and range from mild to severe. Milder reactions include urticaria, itching and flushing, and they are generally mediated by IgE. More severe reactions, such as stridor, bronchospasm, hypotension or other symptoms of anaphylaxis may occur, especially in patients with IgA deficiency and anti-IgA antibodies. Occasional mild allergic reactions often can be prevented by the use of antihistamines or corticosteroids before transfusion. Recurrent allergic reactions can be markedly reduced by washing the red cells to remove the plasma. Patients with IgA deficiency and severe allergic reactions may require blood from IgA -deficient donors.

If signs and symptoms suggest an acute haemolytic reaction, the transfusion should be stopped immediately and intravenous fluids should be administered to maintain intravascular volume. Diuretics may help to preserve renal function. Disseminated intravascular coagulation (DIC) may require additional measures such as heparin. The identification of the patient and the donor unit should be re-checked. The blood bank should also be alerted to the possibility of an undetected alloantibody.

単 Acute haemolytic reactions begin within minutes or sometimes hours of beginning a transfusion and are characterised by the abrupt onset of fever, chills, lower back pain, dyspnea, hemoglobinuria and shock. These unusual reactions most commonly arise from errors in patient identification or blood typing and compatibility testing. The risk of receiving the wrong blood is greater for a patient with thalassaemia who travels to another centre or is admitted to a hospital not familiar with his/her case and medical history. Haemolytic reactions in these patients can still be avoided by (1) the use of optimal methods for identifying the patients and labelling of the sample when blood is obtained for crossmatch, (2) proper linkage of the sample to the donor unit in the blood bank, (3)

単 Delayed transfusion reactions usually occur 5-14 days after transfusion and are characterised by unexpected levels of anaemia, as well as malaise and jaundice. These reactions may be due to an alloantibody that was not detectable at the time of transfusion or to the development of a new antibody. A sample should be sent to the blood bank to investigate the presence of a new antibody and to repeat cross-matching of the last administered unit(s). 単 Autoimmune haemolytic anaemia is a very serious complication of transfusion therapy that usually but not always occurs in patients with alloantibodies. Even red cells from seemingly compatible units (i.e., those units that do not contain the antigen to which there is a known alloantibody) may demonstrate markedly

complication of transfusion. Immunosuppressed patients are at particular risk, but TI-GVHD may also occur in immunocompetent recipients of red cells from a haploidentical donor such as a family member. TI-GVHD usually occurs within 1-4 weeks of transfusion and is characterised by fever, rash, liver dysfunction, diarrhoea and pancytopenia due to bone marrow failure. To reduce the risk of TI-GVHD, donated blood from a family member should be avoided or if used should always be irradiated before transfusion. Leucodepletion alone is inadequate for the prevention of this complication.

shortened survival, and the haemoglobin concentration may fall well below the usual pre-transfusion level. Destruction both of the donor’s and the recipient’s red cells occurs. The serologic evaluation by the blood bank usually shows an antibody that reacts with a wide range of test cells and fails to show specificity for a particular antigen. Steroids, immunosuppressive drugs and intravenous immunoglobulin are used for the clinical management of this situation, although they may give little benefit. Some patients have also been treated with rituximab, but the effectiveness of its use in this situation is presently not well defined. Autoimmune haemolytic anaemia occurs more frequently in patients who begin transfusion therapy later in life (Rebulla, 1991), and should be carefully considered before instituting transfusion therapy for teenagers and adults with thalassaemia intermedia.

ñ Transfusion-associated circulatory overload may occur in the presence of recognised or unrecognised cardiac dysfunction, or when the rate of transfusion is inappropriately fast. Signs and symptoms include dyspnoea and tachycardia, and the chest radiograph shows the classic findings of pulmonary oedema. Treatment focuses on volume reduction and cardiac support, as required.

ñ Transfusion-related acute lung injury (TRALI) is a potentially severe complication that is usually caused by specific anti-neutrophil or anti-HLA antibodies (Swanson, 2006). This complication is characterised by dyspnoea, tachycardia, fever and hypotension during or within six hours of transfusion. Hypoxemia is present and the chest radiograph shows bilateral infiltrates typical of pulmonary oedema although there is no reason to suspect volume overload. Management includes oxygen, administration of steroids and diuretics, and, when needed, assisted ventilation.

ñ Transmission of infectious agents including viruses, bacteria and parasites, are a major risk in blood transfusion (see Chapter 9: Infections in Thalassaemia Major). Even in countries where residual risk of transmission through blood of clinically significant pathogens (HIV, HBV, HCV and Syphilis) has been reduced to minimal levels, problems continue to exist or emerge because: − A limited range of known pathogens is targeted in mandatory donor screening (excludes HPV B-19, HCMV, EBV, HAV, Yersinia enterolitica, parasites, e.g., malaria);

ñ Transfusion-induced graft versus host disease (TI-GVHD) is caused by viable lymphocytes in units of transfused red cell. It is a rare but often fatal

− Transmission of viruses still occurs (window period, sensitivity threshold of tests); − The clinical significance of newly identified infectious agents (HGV, GBV-C, TTV, SEN-V, HSV6,7,8) is not yet completely clarified and donors are not screened for these agents; − Newly emerging infectious agents (WNV, SARS, Avian Flu, prions), constitute serious threats, and; − Absence of widely accepted tests for bacteria (endogenous and exogenous) and for parasitic protozoa associated, for example, with Chaga’s disease, toxoplasmosis and babesiosis.

In many regions of the developing world, where thalassaemia is most prevalent, continued transmission of hepatitis B, hepatitis C and HIV underscores the importance of promoting the quality of national blood transfusion services, including voluntary blood donations, careful donor selection and screening, and public health services’ provision of necessary immunisation.

Summary Recommendations: ñ Careful donor selection and screening – voluntary, regular non-remunerated blood donation. ñ Confirm diagnosis of thalassaemia major. ñ Before initiation of transfusion therapy, confirm laboratory and clinical criteria. ñ Before first transfusion, extended red cell antigen typing of patients at least for C, E and Kell. ñ At each transfusion, give ABO, Rh(D) compatible blood. Matching for C, E and Kell antigen is recommended. ñ Before each transfusion, full cross-match and screen for new antibodies. ñ Keep record of red cell antibodies, transfusion reactions and annual transfusion requirements for each patient. ñ Use leucoreduced packed red cells. Pre-storage filtration is recommended, but blood bank pre-transfusion or bedside filtrations are acceptable alternatives. ñ Washed red cells for patients who have severe allergic reactions. ñ Use red cells stored in CPD-A, as fresh as possible (less than one week old) and in additive solutions for less than 2 weeks. ñ Transfuse every 2-5 weeks, maintaining pre-transfusion Hb above 9-10.5 g/dl, but higher levels (11-12 g/dl) may be necessary for patients with heart complications. ñ Keep post-transfusion Hb not higher than 14-15 g/dl.

Iron Overload

Iron overload occurs when iron intake is increased over a sustained period of time, either as a result of red blood cell transfusions or increased absorption of iron through the gastrointestinal tract (GI). Both of these occur in thalassaemia, with blood transfusion therapy being the major cause of iron overload in thalassaemia major and increased GI iron absorption being more important in thalassaemia intermedia.

based on the assumption that 200 mg of iron is contained in each donor unit. Thus, irrespective of whether the blood used is packed, semi-packed or diluted in additive solution, if the whole unit is given, this will approximate to 200 mg of iron intake. According to the recommended transfusion scheme for thalassaemia major, the equivalent of 100â&#x20AC;&#x201C;200 ml of pure RBC per kg per year are transfused (equivalent to 116232 mg of iron per kg body weight per year or 0.32-0.64 mg/kg/day). Regular blood transfusion therapy therefore increases iron stores to many times the norm unless chelation treatment is given.

In the absence of any mechanism of the human body to excrete excess iron, chelation therapy is essential and constitutes the second important arm, besides transfusion therapy, of the clinical management of these patients.

Increased gastro-intestinal absorption of iron: Normal intestinal iron absorption is about 1-2 mg/day. In patients with thalassaemia who do not receive any transfusion, iron absorption increases several-fold.

The Rate of Iron Loading

It has been estimated that iron absorption exceeds iron loss when expansion of red cell precursors in the bone marrow exceeds five times that of healthy individuals.

Blood transfusion: Knowledge of the rate of iron loading from transfusion to as high a level of accuracy as possible will contribute significantly to the formulation of chelation therapy appropriate for each patient. Simple calculations, such as those described in the Blood Transfusion Chapter of this book, can provide the treating physician with this information.

Transfusion regimens aimed at keeping the pre-transfusion haemoglobin above 9 g/dl have been shown to prevent such expansion (Cazzola 1997). In individuals who are poorly transfused, absorption rises to 3-5 mg/day or more representing an additional loading of 1-2 grams of iron loading per year.

In case organisational or other difficulties do not allow such estimations, a rough approximation can be made 33

Patient’s weight

20 kg

35 kg

50 kg

65 kg

Pure red cell volume (ml) transfused yearly (if 100-200 ml/kg/yr)

2,000-4,000

3,500-7,000

5,000-10,000 6,500-13,000

Yearly iron loading from transfusion (g)

2.3-4.6

4.1-8.2

5.8 -11.6

7.5 -15.1

Daily iron loading from transfusion (mg)

4.7 -9.5

11.1-22.2

15.9-31.8

20.6-41.5

Table 1: Examples of increase in iron stores from transfusion in the absence of chelation

Figure 1: A simplified scheme of iron turnover in healthy adults is shown above in bold arrows. The broken line indicates the effect of transfusion on iron turnover, with an increased daily delivery of haem iron to macrophages which leads to increased iron release rates from macrophages, saturation of transferrin and the appearance of Non-Transferrin-Bound Iron (NTBI) in blood. This in turn causes increased iron uptake by the liver and other parenchyma, such as the heart and endocrine glands. (Adapted from Porter JB. Hematol Oncol Clin North Am. 2005;19:1-6)

(atoms or molecules with unpaired electrons). These can damage lipid membranes, organelles and DNA causing cell death and the generation of fibrosis. In health, iron is ‘kept safe’ by binding to molecules such as transferrin, but in iron overload their capacity to bind iron is exceeded both within cells and in the plasma compartment. The resulting ‘free iron’ damages many tissues in the body and is fatal unless treated by iron chelation therapy.

Toxicity from Iron Overload Mechanism of iron toxicity Iron is highly reactive, easily alternating between two states – iron III and iron II – in a process which results in the gain and loss of electrons, generating harmful free radicals

increase serum ferritin, while vitamin C deficiency may depress it. A sudden and unexpected rise in ferritin level should prompt a search for hepatitis, other infections or inflammatory conditions. In thalassaemia intermedia, serum ferritin tends to underestimate the degree of iron overloading (Pootrakul 1981). Therefore although there is a broad correlation between serum ferritin level and liver iron, the prediction of iron loading from serum ferritin can be unreliable (Olivieri 1995). Importantly, however, at least five studies have shown an association between the control of serum ferritin and prognosis (Gabutti V and Piga A. 1996; Olivieri, N. et al 1994; Telfer PTl, 2000; Davis BA, et al. 2004; Borgna-Pignatti, 2004). Studies have identified a significantly lower risk of cardiac disease and death in at least two-thirds of cases where serum ferritin levels have been maintained below 2,500 Ìg/L (with desferrioxamine) over a period of a decade or more (Olivieri, 1994). Observations with larger patient numbers show that maintenance of an even lower serum ferritin of 1,000 Ìg/L may be associated with additional advantages (Borgna-Pignatti, 2004) (see Table 2).

Complications of iron overload Untreated transfusional iron overload in thalassaemia major is fatal in the second decade of life, usually as a result of cardiac complications (Zurlo 1989). Iron overload also causes pituitary damage, leading to hypogonadism and poor growth. Endocrine complications, namely diabetes, hypothyroidism and hypoparathyroidism, are also seen. Liver disease with fibrosis and eventually cirrhosis, particularly if concomitant chronic hepatitis is present, is also a serious complication. (These complications are described in greater detail in the relevant chapters of this book.)

Monitoring of Iron Overload Monitoring closely and assessing as accurately as possible iron overload is essential in establishing effective iron chelation regimes, such as those mentioned in this chapter, tailored to the individual patient’s specific needs. However, some general principles of monitoring iron overload apply to all treatments:

Liver iron concentration (LIC) Liver iron concentration is now regarded as the reference standard for estimating body iron loading and has been shown accurately to predict total body iron stores (Angelucci, 2000), using the formula:

Serum ferritin This is a relatively easy test to perform, well established, generally correlating with body iron stores and prognostically relevant in thalassaemia major. Up to a value of about 3,000 Ìg/L serum ferritin is secreted in an iron-free form from macrophages, but above this value increasing proportions of ironladen ferritin ‘leaks’ from hepatocytes (Worwood, 1980; Davis, 2004). Day-to-day variations are particularly marked: high degrees of iron loading, inflammation, hepatitis and/or liver damage may falsely

Total body iron stores in mg/kg = 10.6 x the LIC (in mg/g dry wt) Normal LIC values are up to 1.8 mg/g dry wt, with levels of up to 7 mg/g dry wt seen in some non-thalassaemic populations without apparent adverse effects.

Several studies link high Liver Iron Content (LIC) (above 15-20 mg/g dry wt) to worsening prognosis (Brittenham, 1993;

Telfer, 2000), liver fibrosis progression (Angelucci, 1997) or liver function abnormalities (Jensen, 2003).

Table 2: Measuring and interpreting serum ferritin Advantages

Disadvantages

ñ Easy to assess ñ ñ Inexpensive ñ ñ Repeat measures are useful for monitoring chelation therapy ñ Positive correlation with morbidity and ñ mortality

In the absence of prior iron chelation therapy, the risk of myocardial iron loading increases with the number of blood units transfused (Buja and Roberts, 1971; Jensen, 2003). However, more recent studies have identified discordance between liver and cardiac iron loading in some patients receiving iron chelation: patients with increased liver iron may have normal cardiac iron stores, while patients with normal or near normal liver iron may have increased

Indirect measurement of iron burden Fluctuates in response to inflammation, abnormal liver function, metabolic deficiencies Serial measurement required

cardiac iron. While the control of total body iron over a period of years is important to prognosis, liver iron concentrations are less important than cardiac iron in determining the immediate risk of heart failure. Thus, while the long-term control of body iron is important to prognosis, the risk for specific organ damage to the liver or heart at any given time is best assessed by measuring the iron in the organ of interest.

LIC can also be measured accurately using a method known as SQUID (supercoducting quantum interference device). However, only four such machines are currently available worldwide: they are expensive to purchase and maintain, and require dedicated trained staff. Liver iron measured by SQUID has the advantage of possessing a wide linear range but each SQUID machine has to be individually calibrated.

LIC determination should be considered, by the treating physicians for those patients whose serum ferritin levels deviate from expected trends (i.e. those with suspected co-existing hepatitis, or patients on chelation regimens with variable or uncertain responses), as this may reduce the risk of giving either inadequate or excessive doses of chelation therapy. Since the relationship of serum ferritin to iron overload and iron balance has not yet been established, assessment of LIC may be particularly useful when new chelating regimes are being used.

LIC can also now be measured using MRI techniques, previously limited to a relatively narrow linear range. One recently described approach, is the R2 or Ferriscan technique which appears to have acceptable linearity and reproducibility over the range of clinical interest (St Pierre TG, et al, 2005). The technique demonstrates an average sensitivity of >85% and specificity of >92% up to an LIC of 15 mg/g dry wt, and has been registered in the EU and US. For calibration, the MRI machine must use a Phantom supplied by the company, while the data acquired is sent via internet for analysis by dedicated Ferriscan software (payment per scan analysed). A particular advantage of this technique is that it can be applied with little training, at any centre with a reasonably up-to-date MRI machine (see Table 4).

Measurement of LIC can be done by chemical determination on a liver biopsy sample (fresh, fixed or from dewaxing of paraffinembedded material)(see Table3) or by noninvasive methods such as magnetic biosusceptometry (SQUID) (Brittenham, 1993) or magnetic resonance imaging (MRI)(see Table 4). Biopsy is an invasive procedure, but in experienced hands has a low complication rate (Angelucci 1997). Inadequate sample size (<1 mg/g dry weight, 4 mg wet wt or about a 2.5 cm core length) or uneven distribution of iron, particularly in the presence of cirrhosis (Villeneuve 1996), may give misleading results.

Table 3: Measuring LIC by liver biopsy Advantages

Disadvantages

ñ ñ ñ ñ

ñ Invasive, painful procedure associated with potentially serious complications ñ Risk of sampling error, especially in patients with cirrhosis ñ Requires skilled physicians and standardized laboratory techniques

Direct measurement of LIC Validated reference standard Quantitative, specific, and sensitive Allows for measurement of non-heme storage iron ñ Provides information on liver histology/pathology ñ Positive correlation with morbidity and mortality

myocardial T2* to <20 ms (implying increased myocardial iron) is associated with an increased chance of decreased LV function (Anderson et al, 2001). For example, patients with T2* values >20 ms have a very low chance of decreased LVEF. T2* values of 10-20 ms indicate up to a 10% chance of decreased LVEF; 8-10 ms indicates an 18% chance; 6 ms indicates a 38% chance; and T2* values of just 4 ms indicate a 70% chance of decreased LVEF (Westwood, 2007). In centres where such methodology is available, the T2* value may identify patients at high risk of developing a fall in LVEF before it occurs permitting a more informed choice regarding patients whose chelation treatment should be intensified.

Heart function Regular monitoring of left ventricular ejection fraction (LVEF) has allowed identification of a group of patients with poor prognosis at high risk of subsequent heart failure and death who responded well to intensification of desferrioxamine (Davis et al, 2004). Patients with a fall in ejection fraction below reference values for the method used have a 35-fold increased risk of cardiac failure and death, with a median interval to progression of 3.5 years allowing time for intensification of chelation treatment. Left ventricular function can be quantified using MRI, MUGA or echocardiography. The first two methods have advantages over echocardiography in that they are less operator-dependent and therefore more easily adapted to longitudinal monitoring.

The ability to estimate heart iron offers an additional way to stratify risk, opening up a new diagnostic window. However, factors affecting the risk of developing heart failure from myocardial iron overload are complex, while T2* measures storage iron – not in itself directly toxic to cells. Factors that may increase the availability of labile intracellular iron to cause intracellular damage such as myocarditis, or lack of continuous exposure to intracellular chelation, may influence the

Myocardial iron estimation (T2* or other measures) Estimation of myocardial iron using MRI is becoming increasingly available but requires expertise in its use and standardisation. The T2* value in tissues shortens as the iron concentration increases. A shortening of

Table 4: MRI assessment of LIC Advantages

Disadvantages

ñ Assesses iron content throughout the liver ñ Potentially widely available ñ Pathological status of liver and heart can be assessed in parallel

ñ Indirect measurement of LIC ñ Requires MRI imager with dedicated imaging method

Liver iron levels can be assessed using a technique known as R2 (spin echo) MRI, which is a validated and standardised method for measuring LIC MRI=Magnetic Resonance Imaging

risk posed by excess heart iron, and explain why only a proportion of people with short T2* values show abnormal heart function at any moment in time. Prospective data on the relationship between myocardial T2* and survival are still required. However, the relationship between short T2* values (<10ms) and the risk of heart dysfunction is clear (see Table 5).

of which can redox cycle. One way of measuring the NTBI fraction that is labile and can redox cycle is the labile plasma ironâ&#x20AC;&#x2122; assay (LPI assay). However, although the measurement of NTBI (or LPI) has proved a useful tool for examining how chelators interact with plasma iron pools, its value as a guide to routine treatment or prognosis has yet to be demonstrated.

Urinary iron estimation Measurement of the urinary iron excretion can assist in assessing the effect on iron excretion of desferrioxamine (about half of total iron excreted in urine) or deferiprone (over 80% of iron excreted in urine). However, the inherent variability in daily iron excretion necessitates repeated determinations. Faecal iron excretion contributes an additional, but variable (30100%) to the amount of urinary iron excretion, depending on the level of iron stores, the dose of desferrioxamine and the level of haemoglobin (Pippard 1982).

Other markers of oxidative damage A wide variety of markers for oxidative damage have been investigated. Malondialdehyde (MDA) is increased in iron overload, while a wide range of antioxidants are depleted.

There has been interest in the use of antioxidants or naturally occurring products that contain antioxidant properties, such as Curcumin. However, until controlled data are available caution is advised in the use of these, as the effects of antioxidants in the presence of iron can be unpredictable due to redox cycling of iron between the iron (II) and iron (III) states.

Plasma non-transferrin bound iron (NTBI) In iron overload, transferrin, the normal carrier of iron in plasma becomes saturated leaving iron unbound i.e. Non-Transferrin Bound Iron (or NTBI). NTBI is cleared by different cells than transferrin iron, and is mainly responsible for the abnormal pattern of iron distribution in transfusional iron overload. Because these forms of iron rapidly reappear once iron chelators are cleared from the blood, experts suggest that the optimal treatment is 24hour chelation (Porter, 1996).

Other markers of organ dysfunction. These are discussed more fully in other chapters. However, iron overloaded patients should be monitored for evidence of hypoganadotrophic hypogonadism (growth and sexual development and biochemical

NTBI consists of several chemical entities, only some of which are readily chelatable and only some

Iron appears to be removed more quickly from some tissues, such as the liver, than others – for example, the heart.

markers of HH), diabetes mellitus (yearly GTT), hypothyroidism and hypoparathyroidism.

Treatment of Iron Overload

Increasing the dose of chelators given in an attempt to speed up iron removal runs the risk of increasing the toxicity of an iron chelator, by chelating the iron needed for normal tissue metabolism. The twin goals of iron chelation in iron overloaded patients is therefore to decrease tissue iron to safe levels, while simultaneously making the iron as safe as possible by binding the toxic iron pools responsible for causing tissue damage. Iron is constantly being turned over, either as a result of the breakdown of red cells in macrophages or the breakdown of ferritin within cells. These same fractions are redoxactive and potentially harmful; the plasma component of this iron (NTBI) is mainly responsible for the iron loading of tissues. As mentioned above, NTBI appears within minutes of a chelator being cleared from the body. Thus, in order to achieve the second goal of chelation – the minimisation of toxic (labile) iron pools – 24-hour chelation coverage is the ideal, especially in heavily iron loaded patients. Once low levels of iron have been achieved, it is theoretically more appropriate to reduce the dose of chelator than to interrupt or decrease the frequency of chelation.

Goals of iron chelation therapy

The primary goal of chelation therapy is to maintain safe levels of body iron at all times. Unfortunately, once iron overload has accumulated, removal of storage iron is slow and inefficient, because only a small proportion of body iron is available for chelation at any given time. Consequently, when an iron chelator is given, only a small proportion of the drug binds iron, before it is excreted or metabolised. Once a patient is iron overloaded, it may take months or years to reduce body storage iron to safe levels, even with the most intensive treatment. Chelation must therefore begin soon after (2-3 years) the initiation of transfusion therapy.

Table 5: MRI assessment of cardiac iron Advantages

Disadvantages

ñ Rapidly assesses iron content in the septum of heart ñ Iron levels can be quantified reproducibly ñ Functional parameters can be examined concurrently ñ Pathological status of liver and heart can be assessed in parallel

ñ Indirect measurement of cardiac iron ñ Requires MRI imager with dedicated imaging method ñ Technically demanding ñ Methodology remains to be standardized and validated

Cardiac iron levels can be rapidly and effectively assessed using a technique know as T2* (gradient echo) MRI, which is becoming the new standard method MRI=Magnetic Resonance Imaging

Desferrioxamine (Desferal® or deferoxamine)

approximately 14%. Iron excretion with desferrioxamine increases with dose, with body iron stores and in vitamin C deficient patients with the addition of vitamin C.

Desferrioxamine has been in clinical use since the 1970s and widely used as subcutaneous infusions since about 1980. Provided that treatment is 1) begun within 2-3 years of beginning transfusion therapy, 2) administered regularly and 3) administered in adequate doses, desferrioxamine has a wellestablished impact on survival and on cardiac and other complications of iron overload described above (Brittenham, 1993; Gabutti and Piga, 1996; Borgna-Pignatti, 2004).

Effects on serum ferritin Clinical experience over a period of three decades indicates that ferritin can be controlled with desferrioxamine monotherapy, and that maintaining serum ferritin <2500 Ìg/L with this drug is closely linked to protection from heart disease and to improved survival (Olivieri, 1994).

Evidence for the effectiveness of desferrioxamine

However, the results of a formal prospective study on the dose required to stabilise or decrease serum ferritin in large populations have only recently become available.

The main disadvantages of the treatment are that it is costly and that it must be administered parenterally.

The study – a prospective evaluation of changes in ferritin levels and LIC as a function of dose in 290 thalassaemia major patients (Cappellini, 2006) – demonstrated that a mean daily dose of 42 mg/kg resulted in a small decrease in serum ferritin of 364 Ìg/L at one year, whereas a mean daily dose of 51 mg/kg resulted in an average ferritin decrease of approximately 1,000 Ìg/L over one year. Therefore, if the serum ferritin is >2,500 Ìg/l, a mean daily dose of at least 50 mg/kg/day is recommended (except in children – see below).

Mechanism of action and pharmacology Due to its molecular size, desferrioxamine is poorly absorbed from the gut. The higher the dose, the higher the proportion of iron excreted in the faeces rather than the urine. Iron excreted in the urine is derived from the breakdown of red cells in macrophages, whereas faecal iron is derived from iron chelated within the liver (Hershko, 1979; Pippard, 1982). Desferrioxamine has a short plasma half-life (initial half-life 0.3h), being eliminated rapidly in urine and bile. The process of iron chelation ceases soon after an infusion of desferrioxamine is complete. The efficiency of desferrioxamine (measured in terms of percent of dose excreted in the iron bound form) administered at standard 812 hour intervals 5-7 days a week is

Effects on liver iron Administered at least 5 times a week and in sufficient doses, desferrioxamine is effective in controlling liver iron and hence total body iron stores (Brittenham, 1993). The relationship between dose and change in LIC was not examined systematically until recently (Cappellini, 2006), in a study

establishing that a mean dose of 37 mg/kg stabilised LIC for patients with baseline LIC values of between 3 and 7 mg/g dry wt. For patients with LIC values between 7 and 14 mg/g dry wt, a mean dose of 42 mg/kg resulted in a small decrease of 1.9 mg/kg dry wt. In patients with LIC values >14 mg/g dry wt, a mean dose of 51 mg/kg resulted in LIC decreases of an average of 6.4 mg/g dry wt.

Early intervention therefore for decreased LV function is therefore recommended. Once heart function has been improved, sustained compliance is critical to outcome especially while increase myocardial iron remains (Davis, 2004) .

Effects on heart iron (T2*)

Treatment with continuous intravenous desferrioxamine has been shown to improve myocardial iron, even in the most overloaded hearts, with

Thus a dose of 50 mg/kg at least 5 days a week is recommended if a significant decrease in LIC optimal levels (see above) is required. It should be emphasised that these are average changes and that the dose required may increase or decrease depending on transfusion requirement (Cohen, 2005).

average myocardial T2* values of <6 ms (Anderson, 2004). The average rate of improvement at this level of iron loading of the heart is about 3 ms/year in severely overloaded hearts: if improvement is linear it would take several years to normalise the T2* to >20 ms (Porter 2002).

Effects on heart function Subcutaneous therapy has long been known to improve asymptomatic cardiac disease (Freeman, 1983; Wolfe, 1985; Aldouri et al, 1990). Since the introduction of desferrioxamine, the incidence of ironinduced heart disease has fallen progressively in cohorts of patients â&#x20AC;&#x201C; with a key factor being the age of starting treatment (Brittenham, 1994; Borgna-Pignatti, 2004). Symptomatic heart disease can be reversed by high dose intravenous treatment (Marcus, 1984; Cohen, 1989). The same results can be obtained with excellent long-term prognosis with lower doses (50-60 mg/kg/day â&#x20AC;&#x201C; see below) and consequently less drug toxicity using continuous dosing (Davis, 2000 and 2004). Continuous intravenous doses of 5060 mg/kg/day typically normalised LVEF in a period of three months (Anderson LJ, et al., 2004), significantly before liver or heart iron stores had been normalised. However, if advanced heart failure has developed before treatment is intensified, the chances of successful rescue are decreased.

In patients with baseline T2* values of between 8-20 ms, subcutaneous treatment at relatively low doses of 35 mg/kg showed an average improvement in T2* of 1.8 ms over one year (Pennell 2006). At a slightly higher dose of 40-50 mg/kg, five days a week, patients showed an improvement of 3 ms over one year (Porter et al, 2005). Improvement in cardiac T2*, even at low, intermittent doses, has been confirmed by two prospective randomised studies (Pennell, 2006; Tanner, 2006).

Effects on morbidity Regular subcutaneous therapy started before the age of 10 years reduces the incidence of hypogonadism (Bronspiegel-Weintrob, 1990), as well as other endocrine disturbances, including diabetes mellitus (Brittenham, 1993; Olivieri, 1994; Borga-Pignatti, 2004)

demonstrated by the improving survival in patients born between the 1960s and the present day (see Figure 3). Note that only patients born after 1980 will have started treatment at an early age, and that age of starting treatment is a key factor in outcome (Borgna-Pignatti, 2004; Brittenham, 1993; Davis, 2004).

Effects on survival and complications of iron overload As mentioned previously, desferrioxamine was first used to treat iron overload in thalassaemia in the 1970s but was only widely used by infusion after 1980. The benefits of its regular use are clearly

Table 6: Decreasing complications in cohorts born after desferrioxamine was already available.

Birth 1970–74*

Birth 1980–84†

Death at 20 years

Hypogonadism

64.5%

14.3%

Diabetes

15.5%

0.8%

Hypothyroidism

17.7%

4.9%

* IM, DFO introduced in 1975 † SC, DFO introduced in 1980 In 1995, 121 patients switched to DFP (censored at the time)

Survival probability

Figure 3: Increasing probability of survival (% alive at ages shown) with desferrioxamine therapy for thalassaemia, mainly as a result of decreased cardiac iron toxicity, in patient cohorts born between 1960-64 and 1995-97 (Borgna-Pignatti, 2004)

Age (years)

infections such as Klebsiella may also be exacerbated by continued treatment with desferrioxamine.

Desferrioxamine needs to be taken at least five times a week in order to optimise survival (Gabutti and Piga, 1996). Fatal complications from iron overload are also decreased if body iron (as measured by liver iron) is kept below certain levels (Brittenham, 1993) (see below).

It is therefore recommended to cease administration of desferrioxamine in anyone with an unexplained fever, until the cause has been identified and effective antibiotic treatment begun. The decision as to when to recommence treatment with desferrioxamine requires clinical judgement and a careful balancing of the potential risks and benefits. For example, a patient with high cardiac iron or poor heart function may be at high risk if desferrioxamine is withheld during a septic episode, outweighing the risks of infection once antibiotics have been commenced.

Unwanted effects of desferrioxamine Local skin reactions, such as itching, erythema, induration and mild to moderate discomfort are common and may be due to inadequate dilution of desferrioxamine. Ulceration at the site of a recent infusion results from an intradermal infusion of desferrioxamine and should be addressed by deeper placement of the needle in subsequent infusions.

Severe allergy to desferrioxamine is a rare event and can be treated by careful desensitisation, carried out under close medical supervision (Bosquet, 1983; Miller, 1981). Desensitisation is usually successful but may need to be repeated. If unsuccessful, an alternative chelator, such as Deferiprone or Deferasirox (see below), may be considered.

Infection with Yersinia enterocolitica is an important risk associated with desferrioxamine treatment (described in detail in the Chapter 9: Infections in Thalassaemia Major). Such an infection may be difficult to diagnose. However, where there is reasonable clinical suspicion of infection, with Yersinia enterolitica treatment with desferrioxamine should be temporarily discontinued. Infection should be considered in any patient with a febrile illness, especially when associated with abdominal pain, diarrhoea or joint pains, and should be treated as a medical emergency. Desferrioxamine can usually be reintroduced once symptoms have subsided and a full course of antibiotics completed. Other

Dose-related complications Administration of excessive dosage of desferrioxamine may cause the following complications in patients who are not heavily iron loaded: 単

Hearing problems: High frequency sensory neural loss, tinnitus and deafness may occur when desferrioxamine is given in high doses, particularly to young children whose iron burden is low (Olivieri, 1986), and when the therapeutic

essential in all children (see Chapter 4: Endocrine Complications).

index is exceeded (>0.025) (Porter, 1989). Minor sensory neural deficit has been reversible in some cases, but significant hearing loss is usually permanent. It is therefore advisable to monitor audiometry yearly, bearing in mind that audiometric changes due to excessive desferrioxamine are usually symmetrical; asymmetry suggests other pathology. 単

単

Effects on the eye: These were first noted when very high doses (>100 mg/kg/day) were given (Davies, 1983). Symptoms may include night-blindness, impaired colour vision, impaired visual fields and reduced visual acuity. Severe cases may show signs of retinitis pigmentosa on fundoscopy, whereas milder cases are only demonstrable with electroretinography. The main risk factor appears to be high dose (Olivieri, 1986) but complications are also more likely in patients who have diabetes (Arden, 1984) or those receiving concomitant phenothiazine treatment (Blake, 1985). Treatment with desferrioxamine should be temporarily suspended in patients who develop complications, to be reintroduced at lower doses once investigations indicate resolution of the problem.

単

Skeletal changes: These are more common in cases of excessive dosage of desferrioxamine where patients have a low level of iron loading (De Virgillis, 1988; Olivieri, 1992; Gabutti, 1996). Rickets-like bony lesions and genu valgum may be seen in association with metaphyseal changes, particularly in the vertebrae, giving a disproportionately short trunk. Radiographic features include vertebral demineralisation and flatness of vertebral bodies. Patients should be regularly observed for such changes, as they are irreversible.

単

Rare complications: Renal impairment and interstitial pneumonitis have been reported at very high doses of 10 mg/kg/h or more. In patients without iron overload, desferrioxamine has induced reversible coma when used with a phenothiazine derivative (Blake, 1985). Rapid intravenous injection, as may occur during flushing of a line containing desferrioxamine, must be avoided.

Recommended standard therapy

Growth retardation: This may occur if desferrioxamine is administered at too high a dose. Another risk factor is a young age of starting treatment (<3yrs) (De Virgillis, 1988; Piga, 1988). Growth velocity resumes rapidly when the dose is reduced to <40 mg/kg day, while it does not respond to hormonal treatment. It is therefore recommended that doses do not exceed 40 mg/kg until growth has ceased. Regular monitoring of growth is

Standard dose and frequency

The standard recommended method is slow subcutaneous infusion over 8-12 hours of a 10% desferrioxamine solution, using an infusion pump. In general, average doses should not exceed 40 mg/kg until growth has ceased. The standard dose is 20-40 mg/kg for children,

Liver iron concentration (by biopsy, SQUID or MRI) has recently been advocated as a more reliable alternative to serum ferritin (see below). To avoid wasting a costly drug such as desferrioxamine, the dose can be adjusted to the nearest whole vial (500 mg or 2 g), alternating dose volumes between the higher and lower number of vials to achieve the desired mean daily dose.

and up to 50-60 mg/kg for adults, as an 812-hour subcutaneous infusion for a minimum of 6 nights a week. To achieve negative iron balance in patients with average transfusion requirements, a dose of 50 mg/kg/day at least 5 days a week is required (Capellini, 2005). It is important that patients with high degrees of iron loading or at increased risk of cardiac complications receive adequate doses.

When to start desferrioxamine therapy

Use of desferrioxamine by subcutaneous bolus

In thalassaemia major, this should start as soon as transfusions have deposited enough iron to cause tissue damage. This has not been formally determined, but current practice is to start after the first 10-20 transfusions or when the ferritin level rises above 1,000Ìg/l. If chelation therapy begins before 3 years of age, particularly careful monitoring of growth and bone development is advised, along with reduced desferrioxamine dosage. In thalassaemia intermedia, the rate of iron loading is highly variable and the relationship between serum ferritin and body iron can be different from that seen in thalassaemia major. If possible, an estimation of liver iron is advisable before starting treatment to see whether iron has exceeded safe levels (see Figure 4).

If an infusion pump is not available or if 10hour infusions are not tolerated, bolus subcutaneous treatment may be considered if the patient is not at high risk of heart disease. A randomised study has shown that serum ferritin and liver iron can be controlled equally effectively by giving an equivalent total dose (45 mg/kg x 5 per week) either as two subcutaneous ‘boluses’ or as a nightly 10-hour subcutaneous infusion (Yarali, 2006).

Dose adjustment At low ferritin levels, the dose of desferrioxamine may need to be reduced and desferrioxamine-related toxicities monitored particularly carefully. Dose reductions can be made using the therapeutic index (see Figure 4) (Porter, 1989):

Use of vitamin C: Vitamin C increases iron excretion by increasing the availability of chelatable iron, but if given in excessive doses may increase the toxicity of iron. It is recommended not to give more than 2-3 mg/kg/day as supplements, taken at the time of the desferrioxamine infusion so that liberated iron is rapidly chelated. Where a patient has just started on desferrioxamine and it has been decided to administer vitamin C, the vitamin supplement should not be given until after several weeks’ treatment.

Figure 4: Therapeutic Index

Therapeutic index = mean daily dose (mg/kg)* / ferritin (Ìg/l) The aim is to keep the index < 0.025 at all times *mean daily dose = (actual dose received on each infusion x doses per day/7)

Although a valuable tool in protecting the patient from excess chelator, this index is not a substitute for careful clinical monitoring.

Desferrioxamine use during pregnancy: This is discussed in detail in the

Strength of infusion The manufacturers of desferrioxamine recommend that each 500 mg vial of the drug is dissolved in at least 5 ml of water, giving a 10% solution. Concentrations in excess of this may increase the risk of local reactions at the site of infusion.

relevant Chapter 5: Management of Fertility and Pregnancy in ‚-thalassaemia), but Desferrioxamine is not generally recommended unless the risk of cardiac disease in the mother without chelation treatment is high.

Site of infusion Care must be taken to avoid inserting needles near important vessels, nerves or organs. The abdomen is generally the best place. However because of local reactions such as erythema, swelling and induration, it is often necessary to ‘rotate’ the sites used for injection (see Figure 5). Some patients find that the skin over the deltoid or the lateral aspect of the thigh provides useful additional or alternative sites.

Practical issues with subcutaneous infusion Because regular use of desferrioxamine is critical to a good outcome, every effort should be made with each individual to help him or her to find the most convenient way to infuse the drug.

Figure 5: Rotation of infusion sites

Figure 6: Insertion of needles for desferrioxamine infusion

Compliance requires a sustained and secure relationship between doctor, patient and parents, and regular discussion and support are keys to maximising compliance. The reasons for poor compliance are varied. In some cases, parents cannot sanction the daily “ordeal” of chelation therapy for their child. In others, compliance may only become a problem when a child reaches adolescence. Sometimes a previously good complier may become less compliant when other life events or stresses become a burden (see Chapter 15: Psychosocial Support). Helping a patient to take control or ‘self-manage’ is often a useful approach of long-term benefit (see TIF’s book on ‘Compliance to Iron Chelation Therapy with Desferrioxamine’).

Type of needle The best needle to use will depend on the individual. Many patients are happy with butterfly needles of 25 gauge or smaller, which are inserted at an angle of about 45 degrees to the skin surface. The needle tip should move freely when the needle is waggled. Other patients prefer needles that are inserted vertically through the skin and are fixed with an adhesive tape attached to the needle (see Figure 6). Patient preference is highly variable and clinicians should explore the best type of needle for each patient in order to maximise compliance.

Type of infuser There are many types of infusers now available. Newer devices, including balloon pumps, are smaller, lighter, and quieter than their predecessors. For patients who find dissolving, mixing and drawing up desferrioxamine a problem, pre-filled syringes or balloons may be useful. Some pumps are designed to monitor compliance.

Monitoring compliance There is no perfect way to measure compliance. One successful approach may be to give patients a calendar, in which each infusion of desferrioxamine is noted down during the treatment. Some pumps can log usage. Another approach has been to keep a record of empty vials returned to the provider of the desferrioxamine.

Local reactions Persistent local reactions may be reduced by varying the injection sites, lowering the strength of infusion or, in severe cases, by adding 5-10 mg of hydrocortisone to the infusion mixture.

Rescue therapy with continuous infusions In high risk cases, continuous infusion of desferrioxamine is potentially more beneficial than periodic infusions because it reduces the exposure to toxic free iron (NTBI), which returns to pre-treatment levels within minutes of stopping a continuous intravenous infusion (Porter, 1996). The route of administration is not critical, provided that as close to 24-hour exposure to chelation is achieved. Intensification of treatment through continuous, 24-hour intravenous administration of desferrioxamine via an implanted intravenous

Supporting compliance

It is clear that compliance with therapy determines prognosis. However, desferrioxamine treatment is troublesome and time-consuming, and can be painful. Practical approaches to maximising compliance by decreasing local reactions and providing the most convenient pump system have been discussed above. Especially important, however, is support from family and the health care team.

delivery system (e.g. Port-a-cath) (Davis, 2000) or subcutaneously (Davis, 2004) has been shown to normalise heart function, reverse heart failure, improve myocardial T2* (Anderson, 2002) and lead to long-term survival, provided treatment is maintained. In non-high risk cases, options such as encouraging the patient to improve compliance or an increase in dose should be explored before moving to 24-hour treatment.

Suggested dosing A dose of at least 50 mg/kg/day and not exceeding 60 mg/kg/day is recommended as a 24-hour infusion (Davis, 2000 and 2004). Higher doses have been used by some clinicians however DFO is not licensed at these doses and the risk of retinopathy increases. Addition of vitamin C is recommended only when acute heart dysfunction has settled, which usually occurs by three months of continuous treatment (Anderson, 2004). As ferritin falls, the dose but preferably not the duration of treatment can be reduced, in line with the therapeutic index (see above).

Consideration for intensive therapy Intensification should be considered in the following cases: 単 severe iron overload - persistently very high ferritin values* - liver iron > 15 mg/g dry weight *

Management of in-dwelling intravenous lines Infection and thrombosis of the catheter may occur. Careful aseptic procedures must be followed in order to prevent possible infection by Staphylococcus epidermidis and aureus, which when established are difficult to eradicate and often removal of the infusion system becomes necessary. The risk of thrombosis and infection is likely to be greater in centres that do not have regular experience in the use of long-term indwelling lines. Use of prophylactic anticoagulation is advised as line-thrombosis is relatively common in thalassaemia major (Davis, 2000). As development of a thrombosis can occur at the tip of the catheter, it is advisable, if possible to avoid placing the tip in the right atrium.

単 significant cardiac disease^: - significant cardiac dysrhythmias - evidence of failing left ventricular function - evidence of very severe heart iron loading (T2*<6 ms) 単 prior to pregnancy or bone marrow transplantation, when rapid reversal of iron loading may be desirable * If the only abnormalities are high ferritin or LIC, it would be usual to try to increase the dosing (for example, to 5060 mg/kg) or the duration or the frequency of subcutaneous infusions.

When cardiac disease is present, 24-hour intensive therapy(or combination therapy with desferrioxamine and deferiprone-see below) is necessary and simple increments in conventional 8-12-hour dosing are not recommended.

Intravenous desferrioxamine with blood transfusion This has been used as a supplement to conventional therapy (e.g. 1 g over 4 hours piggy-backed into the infusion line), but its contribution to iron balance is very limited. Special attention must be given to avoiding

accidental boluses due to desferrioxamine collecting in the dead space of the infusion line. Co-administration of desferrioxamine and blood can lead to errors in interpreting side effects such as acute fever, rashes, anaphylaxis and hypotension during blood transfusion. Desferrioxamine should never be added directly into the blood unit.

Effects on serum ferritin Four prospective randomised trials compare the effects of deferiprone on serum ferritin at baseline and at follow-up (Maggio, 2002; Gomber, 2004; Pennell, 2006; Ha, 2006). Pooled analysis shows a statistically significant decrease in serum ferritin at six months in favour of desferrioxamine (Gomber, 2004; Ha, 2006), with no difference between the two drugs at 12 months (Maggio, 2002; Pennell, 2006). There are numerous nonrandomised cohort studies demonstrating a lowering of serum ferritin at doses of 75 mg/kg/day administered in three doses. The effect on serum ferritin at this dose appears greater at higher baseline ferritin values. In these studies significant decreases in serum ferritin are seen in patients with baseline values above 2,500 Ìg/L (Al-Refaie et al., 1992; Agarwal, 1992; Oliveiri, 1995) but not with values below 2,500 Ìg/L (Olivieri,1995; Hoffbrand,1998; Cohen, 2000).

Deferiprone (Ferriprox®, Kelfer®, L1) Deferiprone is an orally absorbed iron chelator that began clinical trials in the UK in the 1980. It was first licensed for use in thalassaemia in India, followed by the European Union and other countries outside the US and Canada, in the late 1990s.

Pharmacology

Effects on liver iron

Three molecules of deferiprone are required to bind one iron atom, and the efficiency of iron binding decreases with falling concentrations of iron or of chelator. The drug is rapidly metabolised and inactivated in the liver by glucuronidation of one of its iron binding sites (Kontoghiorghes, 1998). At currently used doses, about 6% of the drug binds iron before it is excreted or metabolised (6% efficiency) (Aydinok, 2005). Unlike desferrioxamine, iron excretion is almost exclusively in the urine.

Four trials that measure change in liver iron concentration (LIC) from baseline after a period of treatment with deferiprone compared with desferrioxamine are available (Olivieri, 1997a; Maggio, 2002; Pennell, 2006; Ha, 2006). One study showed increases in LIC at 33 months of 5 mg/g dry wt with deferiprone (n=18) and 1 mg/g dry wt with desferrioxamine (n=18) (Olivieri, 1997). A second study showed an average decrease in LIC at 30 months with both deferiprone (n=21) and desferrioxamine (n=15) (Maggio, 2002). A third study found decreases in LIC at one year of 0.93 mg/g dry wt with deferiprone (n=27) and 1.54 mg/g dry wt with desferrioxamine (n=30) (Pennell, 2006).

Evidence of effectiveness of deferiprone There are considerable accumulated publications about the effects of deferiprone. Most of these have not been randomised controlled trials, making comparison with desferrioxamine difficult.

Another study reported decreases in LIC at six months with both deferiprone (6.6 mg/g dry wt, n=6) and desferrioxamine (2.9mg/g dry wt, n= 7) (Ha, 2006). In a non-randomised prospective study, using Deferiprone, LIC increased from baseline by 28% at two years and by 68% at three years of treatment (Fischer, 2003). In other studies where only single biopsies were performed after several years of Deferiprone treatment, LIC has been found to be above 15 mg/g dry wt in variable proportions of patients: 11% (Del Vecchio, 2002), 18% (Tondhury, 1998) and 58% (Hoffbrand et al, 1998).

was reported for either drug (Maggio, 2002). A recent study using a new technique multislice, multiecho T2* demonstrated improved T2* values in the Deferiprone group compared to the Desferrioxamine group (Pepe, 2006).

Effects on survival and complications of cardiac disease In six randomised prospective comparisons with desferrioxamine, mortality was not reported as an outcome measure while in a seventh, one death reported in the Deferiprone arm, but not in the Desferrioxamine arm was considered as due to cardiac complications (Ha, 2006). In a retrospective cohort analysis of patients treated with deferiprone or desferrioxamine, no deaths were reported (n=157) in the Deferiprone arm in contrast to the desferrioxamine-treated patients (BorgnaPignatti, 2006a), although some caution was expressed by the authors with regard to the interpretation of these results. In this analysis the author noted that there were no cardiac events in 750 patient years of exposure to Deferiprone in more than 150 patients.

Effects on heart function One prospective one-year study found that in patients with normal left ventricular ejection fraction, deferiprone given at high doses (92 mg/kg) improved heart function (Pennell, 2006). In another randomised study over one year, no difference in LVEF or other measures of LV function was seen with either deferiprone at 75 mg/kg/day or desferrioxamine (Maggio, 2002). A prospective study of the effects of deferiprone monotherapy on patients with abnormal LVEF or symptomatic heart disease has not been reported.

Compliance with deferiprone One study comparing compliance with deferiprone and desferrioxamine found rates of 95% and 72% respectively (Olivieri, 1990), while another found 94% and 93% respectively (Pennell, 2006).

Effects on heart iron The effect of deferiprone monotherapy on heart iron has been reported in two prospective studies. One study found significant improvement in T2* after one year at 92 mg/kg of deferiprone daily. Patients with starting T2* values of between 8 and 20 ms showed an average increase from 13 ms to 16.5 ms in the deferiprone group, and 13.3 to 14.4 ms in the desferrioxamine group (Pennell, 2006). In another randomised study, of deferiprone and desferrioxamine administered at standard doses over one year, no change in heart iron estimated by T2

Two important points to be taken into consideration are (i) compliance with any treatment tends to be higher in studies than in routine use, and (ii) although compliance with oral treatment is expected to be better, it cannot be taken for granted requiring, as in the use of Desferrioxamine, constant supervision and patient support.

reintroduced, and the use of GM CSF should be considered in the case of agranulocytosis; offlabel use of the drug should be avoided.

Unwanted effects with deferiprone Neutropenia, agranulocytosis and thrombocytopenia

Gastrointestinal symptoms

The most serious and potentially fatal adverse effect of deferiprone is agranulocytosis (absolute neutrophil count, or ANC*, <500/mm3). The condition may occur with thrombocytopenia, but also isolated thrombocytopenia has occasionally been reported. Onset of agranulocytosis is variable, from a few months to nine years. In a prospective trial where weekly neutrophil counts were undertaken and where deferiprone was discontinued when the ANC was <1,500/mm3, agranulocytosis developed in 0.2/100 patient years and milder forms of neutropenia (ANC 500-1500/mm3) occurred in about 2.8/100 patient years (Cohen, 2000 and 2003). Recently, 46 cases of agranulocytosis, were reported, in Europe with nine related deaths (Swedish Orphan, safety alert, 2006). Five of these cases were in patients who had been prescribed the drug for an unspecified â&#x20AC;&#x2DC;off labelâ&#x20AC;&#x2122; indication, and several were not receiving weekly blood count monitoring. Swedish Orphan has subsequently issued the following recommendations on the use of deferiprone:

Nausea and change in appetite (loss or gain) occur in 3-24% of patients (Ceci 2002; Cohen et al, 2000).

Effects on liver Variable fluctuation in liver enzymes has been reported. About a quarter of patients show ALT fluctuation of twice the normal upper limit (Cohen, 2000). One prospective randomised study showed no significant endof-study changes in liver enzymes with deferiprone or desferrioxamine (Pennell, 2006). An observational report of fibrosis after treatment for three or more years (Olivieri, 1998) has not been supported by other reports (Tondury, 1998; Hoffbrand, 1998; Wanless, 2002). A relevant prospective randomised study investigating the progression to fibrosis, using Deferiprone for one year, showed no difference as compared with Desferrioxamine, over the same period and no difference in baseline and end-oftreatment liver function tests (Maggio, 2002).

Arthropathy

ANC* should be monitored every week or more frequently if there are signs of infection; concomitant treatment that could affect the white cell count should be avoided; if severe neutropenia or agranulocytosis develop, the drug should be stopped and not

The frequency of arthropathy varies greatly between studies, from as low as 4.5% at one year (Cohen, 2000) to 15% after four years (Cohen, 2003) in a predominantly European patient group, and as high as 33-40% in a study of patients in India (Agarwal et al, 1992; Choudhry et al, 2004). It is not yet clear whether these differences reflect environmental or genetic differences, or differences in iron overload between populations at the start of treatment.

* ANC: absolute neutrophil count

Symptoms range from mild non-progressive arthropathy, typically in the knees, controllable with non-steroidal antiinflammatory drugs to (more rarely) severe erosive arthropathy that may progress even after treatment is stopped. Cases involving other joints, such as wrists, ankles and elbows, and avascular necrosis of the hips, have also been described.

As a result of the various unwanted effects, 20-30% of patients are unable to sustain long-term treatment with deferiprone (Hoffbrand, 1998). Frequency of adverse events compared with desferrioxamine Adverse effects have been reported in four randomised studies comparing deferiprone with desferrioxamine. One trial has reported data that allows comparison of the probability of an adverse event with deferiprone and desferrioxamine (Maggio, 2002), establishing a statistically significant two-fold difference between deferiprone (34%) and desferrioxamine (15%), but no difference between temporary or permanent treatment withdrawal.

Treatment should be stopped where joint symptoms continue despite a reduction in deferiprone dose and are not controlled by non-steroidal antiinflammatory drugs. Neurological effects Neurological complications are very rare and have been typically associated with unintentional overdosing. Rare neurological effects have included cognitive effects, nystagmus, walking disorders, ataxia, dystonia and impaired psychomotor skills. These effects appear to improve on cessation of treatment.

Pregnancy Deferiprone is teratogenic in animals and must never be given to patients attempting to conceive. Until more is known, potentially fertile sexually active women and men taking deferiprone must use contraception. Deferiprone should not be used in pregnant women.

Effects on eye and ear There have been isolated reports of loss of vision (central scotoma). One study reported continued audiometric deterioration after switching from desferrioxamine to deferiprone (Chiodo, 1997). It is therefore advisable to monitor for CNS, audiometric and visual function in patients on regimes containing deferiprone.

Recommended treatment regimens with deferiprone According to the official European licensing Agency (EMEA*), Deferiprone could be used as a second line drug, for removing iron in patients who are unable to use Desferrioxamine or in whom DFO therapy has proven ineffective.

Other effects Zinc deficiency during deferiprone therapy has also been observed in some patients, especially those with diabetes.

Standard dosing and frequency The daily dose of deferiprone that has been evaluated most thoroughly is 75 mg/kg/day, given in three doses. In the EU, the drug is * EMEA:

European Agency for the Evaluation of Medicinal Products

monitoring of the blood count throughout treatment.

licensed for doses up to 100mg/kg/day but formal safety studies of this dose are limited. The standard dose of 75mg/kg/day administered in three separate doses is therefore recommended.

Combined Desferrioxamine and Deferiprone

Dose escalation with deferiprone. Doses of 100mg/kg/day have been given in at least one prospective study (Pennell, 2006), with no increase in side-effects reported. High dose monotherapy with deferiprone has not yet been prospectively evaluated for safety and effectiveness for patients with abnormal heart function, and combination therapy with deferiprone and desferrioxamine (see below) or intensive therapy with desferrioxamine as a 24-hour infusion should be recommended for this group of patients.

A variety of regimens involving combinations of deferiprone and desferrioxamine have been used by clinicians, either in the context of a formal trial or on an ad hoc basis, usually when monotherapy with desferrioxamine or deferiprone has failed to control iron overload or its effects.

Pharmacology In principle, chelators can be given at the same time as each other (simultaneously) or following one another (sequentially). There is considerable variation in the way in which sequential treatment can and has been administered. Some investigators have used the term ‘alternating therapy’ to describe the use of two drugs administered on alternate days, reserving the term ‘sequential therapy’ for when desferrioxamine is given at night and deferiprone during the day. In practice regimes may involve a component of ‘sequential’ and ‘alternating’ therapy, such as when desferrioxamine is given three times a week (alternate nights) and deferiprone every day. Most regimes have tended to give deferiprone daily, at standard doses, combined with varying frequency and dosing of desferrioxamine.

Age of commencement Although there have been some retrospective reports of its use in children, the safety and efficacy of this drug has not been formally evaluated in children under 10 years of age.

Use of vitamin C The effect of vitamin C on iron excretion with deferiprone is not clear and is thus not recommended.

Safety monitoring Weekly blood counts are necessary throughout treatment so that a falling white cell count can be detected early and treatment stopped before overwhelming sepsis develops. If severe neutropenia or agranulocytosis develops, re-challenge is contra-indicated. Recent reports of eight deaths from agranulocytosis in patients treated in Europe, cited above, only emphasise the importance of scrupulous

The pharmacology of combinations of chelators may be fundamentally different depending on whether the drugs are present in cells or plasma at the same time. By giving desferrioxamine at night and deferiprone by

day (sequentially), 24-hour exposure to iron chelation can be achieved (similar to that achieved with 24-hour desferrioxamine infusion or once daily deferasirox. (For more on deferasirox (Exjade), see below). This has the theoretical advantage of 24-hour protection from labile (redox active) iron (Cabantchik, 2005). If the drugs are given at the same time (simultaneously), they may interact in a process that involves the â&#x20AC;&#x2DC;shuttlingâ&#x20AC;&#x2122; of iron, which may lead to additional chelation of iron from cells or plasma and so improved iron removal. However, there is also a possibility of chelation from metalloenzymes, leading to increased drug-related toxicity.

achieved with two nights of desferrioxamine plus seven days of deferiprone at 75 mg/kg (n=14). Another randomised study, involving 30 patients and three different treatments (Gomber et al, 2004), found that the decrease in serum ferritin was greatest with five nights of desferrioxamine, albeit not significantly different from that achieved with a combined treatment of desferrioxamine two nights a week plus deferiprone seven days a week. A third randomised study, involving 60 patients (Galanello, 2006), found no difference in the level of decrease in serum ferritin in patients randomised to combined treatment (two days desferrioxamine at 33 mg/kg + seven days deferiprone at 75 mg/kg) or to desferrioxamine five nights a week at 33 mg/kg.

In short, the simultaneous use of these drugs has not been tested formally in large enough patient groups to allow firm, evidence-based recommendations about efficacy and safety.

Taken together, these studies suggest that serum ferritin can be controlled with a relatively small dose of desferrioxamine given twice a week, when combined with deferiprone at standard doses (75 mg/kg/day). In a more recent randomised study of 65 patients (Tanner, 2007), serum ferritin was decreased more by combined treatment (desferrioxamine five days a week plus deferiprone seven days a week) than with standard desferrioxamine monotherapy (40 mg/kg five times a week).

However, data from several prospective studies indicate that sequential (or alternating) use of these chelators can be used to achieve control of iron overload and improvement in heart iron measurements.

Evidence of efficacy of combined treatments

Effects of sequential use on liver iron One randomised study, assessing the effects on liver iron of combined treatment compared to desferrioxamine monotherapy (n=60), found LIC of <7 mg/g dry wt at baseline â&#x20AC;&#x201C; a figure maintained, on average, in both arms of the study (Galanello, 2006). Another prospective randomised study, comparing the effect of desferrioxamine monotherapy administered subcutaneously five times a week with that of deferiprone

Effects of sequential use on serum ferritin Four randomised studies have compared levels of serum ferritin in patients using combined treatments with those under other treatment regimes. One study (Mourad et al, 2003) found the decrease in serum ferritin achieved with five days of desferrioxamine monotherapy (n=11) to be similar to that

(T2* 8-20 ms), myocardial T2* changes with combined deferiprone 75 mg/kg seven days a week plus desferrioxamine five days a week were compared with patients on standard desferrioxamine five times a week (Tanner, 2007). T2* improved in both groups but was significantly greater (6 ms) with combined treatment than with desferrioxamine monotherapy (3 ms). In an observational study, the T2 of the heart improved with combined therapy (Kattamis, 2006).

administered daily at 75 mg/kg daily or deferiprone at 75 mg/kg daily, plus twiceweekly desferrioxamine, found that the decrease in liver iron was highest in the desferrioxamine monotherapy group and lowest in the deferiprone monotherapy group, with sequential combination treatment showing an intermediate effect (Aydinok, 2005). A further randomised study, comparing deferiprone plus desferrioxamine five times a week with desferrioxamine monotherapy five times a week (n=65), found that an improvement in liver T2* (as a surrogate measure of LIC) was greater in the combination arm (Tanner, 2007).

Safety of combined treatment Formal safety data on combined treatment are limited. A meta-analysis of the incidence of agranulocytosis with combined regimes compared with deferiprone monotherapy suggests that the risk may be increased several-fold, although the number of patients that qualify for evaluation is small (Macklin, IND submission to FDA, 2004). The increased incidence appeared to occur mostly in those regimes where the drugs were administered simultaneously. In a recently reported prospective study, one case of agranulocytosis and two of neutropenia were seen at one year in the combination arm, including 32 patients (Tanner, 2007), while no increase in arthropathy was observed in the same group of patients.

Effects of sequential use on heart function In the above-mentioned randomised controlled study of 65 patients (Tanner, 2007), with baseline LVEF >56% changes in LVEF improved by approximately 2.5% in the combination arm and 0.5% in the desferrioxamine monotherapy arm. Two observational studies have also reported changes in heart function under combined treatment. In 79 patients treated with a variable desferrioxamine regimen plus deferiprone at 75 mg/kg seven days a week for a variable time, there was an improvement in LVEF measured by echocardiography (Origa, 2005). In an observational study of 42 patients with sequential use of treatment over three to four years (deferiprone 75 mg/kg/day plus desferrioxamine two to six days a week), the LV shortening fraction improved (Kattamis, 2006).

Conclusions and possible treatment regimens

The above-mentioned studies suggest that some combined regimens can control iron overload in the liver and heart where monotherapy is not having the desired effects. In general, if a patient is not doing

Effects of sequential use on cardiac iron In a randomised controlled study of 65 patients with moderate heart iron loading

provides 24-hour chelation from labile plasma iron (Nisbet-Brown, 2003; Galanello, 2003). The efficiency of chelation is 28%, over a wide range of doses and levels of iron loading.

well with monotherapy, combined treatment offers an additional approach (as does intensive therapy with at least 50 mg/kg/day of desferrioxamine for as many hours a day as is practicable-see above). For patients with very high levels of heart iron or cardiac dysfunction, 24-hour treatment with desferrioxamine and daily therapy with deferiprone should be strongly considered.

Evidence of effectiveness of deferasirox Deferasirox has undergone preclinical and clinical evaluation that has included largescale prospective randomised studies involving over 1,000 patients, to assess safety, efficacy and the dose response effects of treatment. At this time, evidence of effectiveness is confined to serum ferritin and liver iron.

Dose effect on serum ferritin A dose-dependent effect on serum ferritin has been observed in several studies (Cappellini, 2006; Piga, 2006). A prospective randomised study comparing the effects of deferasirox in 296 thalassaemia major patients with that of desferrioxamine in 290 patients found that 20 mg/kg daily of deferasirox stabilised serum ferritin close to 2,000 Ìg/L. At 30 mg/kg, serum ferritin was reduced, with an average fall of 1,249 Ìg/L over one year (Cappellini, 2006). Longer-term analysis of ferritin trends shows that the proportion of patients with ferritin values <1,000 Ìg/L and less than 2,500Ìg/L is decreasing progressively with time (Porter, 2006).

Deferasirox (Exjade) Deferasirox was developed by Novartis as a once-daily, oral monotherapy for the treatment of transfusional iron overload. The drug has been licensed as first-line monotherapy for thalassaemia major in over 70 countries worldwide, including the US (2005) and the EU (2006). The average follow up in large-scale prospective trials at the time of writing is three years.

Pharmacology This is an orally absorbed iron chelator, with two molecules binding each iron atom. The tablet is dissolved in water (or apple juice) using a non-metallic stirrer, and consumed as a drink once daily, preferably before a meal. Metabolic iron balance studies show iron to be excreted almost entirely in the faeces, with less than 0.1% of the drug eliminated in urine (Nisbet-Brown, 2003). Metabolism occurs predominantly by glucuronidation in the liver. Due to the long plasma half-life (nine to 11 hours), once-daily administration

Dose effect on liver iron and iron balance In the same prospective study, iron balance was achieved at 20 mg/kg/day, with mean LIC constant over one year (Cappellini, 2006). Negative iron balance was achieved at 30 mg/kg/day, while mean LIC fell by 8.9 mg/g dry wt (equivalent to a decrease in body iron

of 94 mg/kg body weight) over one year. These are average trends and a closer analysis shows that the blood transfusion rate influences the response to treatment (Cohen, 2005). Thus for patients in the high or low transfusion category (see Table 7), the average dose required to achieve iron balance is accordingly adjusted up or down from 20mg/kg/day (Cohen, 2005). Some patients will still fail to achieve negative iron balance at a daily dose of 30 mg/kg/day of deferasirox, and studies are currently underway to assess the effectiveness and safety of higher doses.

and estimated heart iron were not evaluated formally as part of the drug registration process, and formal prospective studies on both heart function and heart iron are now in progress. Retrospective analysis of effects on myocardial T2* after one year and two years of treatment suggests that this measure can be improved in a significant proportion of patients with pre-existing abnormal T2* values (Porter, 2005). Patients with normal LVEF showed no change in this measure over one year (Porter, 2005).

Unwanted effects with deferasirox

A more moderate reduction in LIC occurred in children under six years old, despite the administration of an average dose of 21.9 mg/kg in this subgroup. However, these patients had the highest mean transfusional iron intake.

Gastrointestinal effects Gastrointestinal disturbances â&#x20AC;&#x201C; typically mild and transient â&#x20AC;&#x201C; occurred in 15% of patients and included abdominal pain, nausea and vomiting, diarrhoea and constipation, lasting a median of less than eight days. These

Effects on heart iron and heart function The effects of deferasirox on heart function

Transfusion rate

% of patients

LIC change*

so transfused

at 20mg/kg

at 30mg/kg

Low (<0.3 mg/kg/day)

24%

-4

-.9.5

Intermediate (0.3-0.5 mg/kg/day)

59%

-2

-9.0

High (>0.5 mg/kg/day)

17%

+1.8

-4.0

*in mg/g dry wt Table 7: Relation of transfusion rates with LIC.

symptoms rarely required dose adjustment or discontinuation.

Effects on the liver Overall a decrease in ALT* was seen, which paralleled improvements in LIC (Deugnier, 2005). Two patients out of 296 developed elevated ALT values greater than twice the ULN while receiving deferasirox for one year, which the investigator reported as related to the administration of the drug.

Skin rashes These occurred in (11%) of patients and were typically pruritic, maculopapular and generalised, but occasionally confined to palms and soles of the feet. A rash typically developed within two weeks of starting treatment. A minority of patients required permanent discontinuation of therapy, and mild rashes often resolved without dose modification.

Other effects No agranulocytosis, arthropathy or growth failure was associated with deferasirox administration. Comparing 296 patients who received deferasirox in a one-year prospective randomised study with 290 patients receiving desferrioxamine, deafness, neurosensory deafness or hypoacusis were reported as adverse events in eight patients on deferasirox and seven in desferrioxamine. Cataracts or lenticular opacities were reported as adverse events in two patients on deferasirox and five on desferrioxamine (Cappellini, 2006).

Increase in serum creatinine An increase in serum creatinine â&#x2030;Ľ30% on at least two consecutive readings was observed in 38% of patients receiving deferasirox, most frequently at doses of 20 mg/kg and 30 mg/kg (Cappellini, 2006). These increases were sometimes transient and generally within the normal range, never exceeding two times the upper limit of normal (ULN), and were more frequent in the population of patients having the most dramatic decrease in LIC and serum ferritin. In the randomised study, a dose reduction of 33-50% was planned if at least two consecutive increases in serum creatinine were >33% above baseline. As the creatinine spontaneously normalised in a number of cases, dose reductions were instituted in only 13%. In about 25% of those cases, the creatinine then returned to baseline, while in the rest it remained stable or fluctuated between baseline and the maximum increase observed prior to dose reduction. With follow up of a median of three years at the time of writing, no evidence of progressive renal dysfunction has been reported where the above doses and modifications are used. Further work on the mechanism of creatinine increases is being undertaken.

Convenience and impact on quality of life Studies comparing satisfaction and convenience of DFS with DFO in thalassaemia major show a significant and sustained preference for DFS (Cappellini, 2006). Total withdrawals in deferasirox-treated patients were 6% at one year compared with 4% with desferrioxamine (Cappellini, 2005). This compares with a dropout rate of 15% at one year with deferiprone (Cohen, 2000). Based on thalassaemia patient reported preferences for DFS and DFO, published compliance data with DFO and the probability of complications from iron overload in relation to compliance with DFO, the cost effectiveness per qualityadjusted life year (QALY) gained is 4.1 per patient for DFO and 8.1 per patient for deferasirox. * ALT: Alanine L-Aminotransferase

Recommended treatment regimens with deferasirox

The drug also appears to be palatable to children at this young age. On the basis of present knowledge, the criteria for starting treatment (ferritin level, age, number of transfusions) do not differ from those of desferrioxamine.

Recommended dosing

Other indications and contraindications

The drug is taken orally as a suspension in water, once daily, preferably before a meal. A starting dose of 20 mg/kg is recommended for thalassaemia major patients who have received 10-20 transfusion episodes and currently receive standard transfusion at rates of 0.3-0.5 mg of iron/kg/day. In those patients in whom there is a higher rate of iron intake from transfusion (>0.5 mg/kg/day) or in patients with pre-existing high levels of iron loading, where a decrease in iron loading is clinically desirable, 30 mg/kg/day is recommended. For patients with a low rate of iron loading (<0.3 mg/kg/day), a dose of 10-15 mg/kg may be sufficient to control iron loading.

Deferasirox is contraindicated in patients with renal failure or significant renal dysfunction. For patients with evidence of significant heart dysfunction (e.g. LVEF below reference range) there is very limited clinical experience and treatment cannot be recommended at this time for patients with heart failure or poor LV function. The combined use of deferasirox with other iron chelators has also not been formally assessed and therefore cannot be recommended at this time. The drug should not be used in pregnant women.

Experience of use in patients with pre-existing renal disease (baseline creatinine outside reference range) is insufficient at this time to recommend its use. As the median follow up in large-scale studies is three years at this time, vigilance in monitoring for possible longterm effects is still advisable.

Age of commencement Prospectively randomised studies of deferasirox in children as young as two years of age have been carried out (Cappellini, 2006; Galanello, 2006).

A fall in LIC was seen across all age groups analysed, with no age-related adverse effects: in particular, no adverse effects on growth, sexual development or bones were seen (Piga, 2006).

Summary of Iron Overload and its treatment: ñ 1.08 mg of iron in 1ml of pure red cells (HCT = 100%); ñ Rate of iron loading: volume of RBC x 1.08 (annual transfusion requirements x donor Hct = volume of RBC). On average 200mg iron/donor unit; ñ Recommended transfusion 100-200 ml/kg/year is equivalent to 116-232 mg iron/kg/year or 0.32-0.64 mg/kg/day; ñ Serum ferritin broadly related to body iron. When high, the following should be considered: (i) iron overload; (ii) inflammation; (iii) hepatitis; and/or (iv) liver damage. When serum ferritin is low, the following should be considered: (i) low body iron; (ii) vitamin C deficiency. In thalassaemia intermedia, ferritin underestimates the degree of iron overload. Ferritin levels related to low risk are below 2,500 mg/l, preferably below 1,000 mg/l; ñ Ranges of LIC reflecting levels of RISK:Very low risk = <1.8 mg/g dry weight Low to moderate risk = 1.8 - 7 mg/g dry weight; Moderately high to high risk = 7 - 15 mg/g dry weight; Very high risk = > 15 mg/g dry weight; Total body iron stores = 10.6 x LIC (mg/g dry weight); LIC is measured by: a) Liver biopsy – indicated if ferritin levels deviate from expected trends, if coexistent hepatitis and if uncertain response to chelation; b) SQUID – not universally available; c) MRI – R2. ñ Cardiac iron reflected by heart function tests and measured by MRI T2*; ñ Urinary iron – used to monitor desferrioxamine or deferiprone dose effects. Variability in daily excretion, and ñ NTBI and LPI – not yet routinely used.

Desferrioxamine: ñ Initiate treatment after first 10-20 transfusions or ferritin level above 1,000 Ìg/l; ñ If before 3 years of age monitoring of growth and bone development is recommended; ñ Therapeutic index = mean daily dose (mg/kg) (Mean daily dose = actual dose of each infusion x doses/7 days) /ferritin (mg/l). Keep index < 0.025 at all times; ñ Standard treatment: a) Slow subcutaneous infusion over 8-12 hours, b) 10% desferrioxamine solution (5 ml water for each 500 mg vial), and c) infusion pump (several types available); ñ Standard dose: a) children 20-40 mg/kg (not exceeding 40 mg/kg, until growth has ceased), and b) adults 50-60 mg/kg. Infuse 8-12 hours 6 nights minimum per week; ñ Alternative route: subcutaneous bolus – two S.C. boluses/day to a total daily dose of 45 mg/kg; ñ Vitamin C-dose limited to 2-3 mg/kg/day given orally at the time of infusion; ñ Pregnancy – desferrioxamine can be used in pregnancy. It should be interrupted during the first trimester and can be used in the second and third trimesters, in selected cases; ñ Intensive chelation with desferrioxamine – continuous 24-hourly infusions IV or SC. Indications: a) Persistently high serum ferritin; b) LIC > 15 mg/g dry weight; c) Significant heart disease, and; d) Prior to pregnancy or bone marrow transplantation Dose: 50 mg/kg/day (up to 60 mg/kg/day) ñ In-dwelling catheters: danger of infection and thrombosis.

Deferiprone: ñ Standard dose: 75 mg/kg/day in 3 divided dose (up to 100 mg/kg/day, but as yet not enough information); ñ Children above 10 years of age; ñ Vitamin C concomitant treatment not recommended; ñ Weekly blood counts (more frequently if signs of infection); ñ Pregnancy – stop treatment. It is recommended that sexually active patients should use contraception;

COMBINATION THERAPY. In patients for whom monotherapy with desferrioxamine or deferiprone is not controlling body levels of iron or myocardial iron or in the presence of significant heart disease, combined regimes offer an alternative that can reduce iron levels in both the liver and heart. No recommendations as to which is the more effective combination can be made at present. CAUTION: agranulocytosis may be more frequent in combination therapy, especially in simultaneous use.

Deferasirox: ñ Recommended dose: Starting dose 20 mg/kg/day. After 10-20 transfusions (iron intake (0.3-0.5 mg/kg/day); If pre-existing iron overload (or iron intake > 0.5 mg/kg/day), the dose of 30 mg/kg/day is recommended. For patients with low rate of iron loading (<0.3 mg/kg/day), lower doses may be sufficient to control iron loading; some patients will still fail to achieve negative iron balance at a daily dose of 30mg/kg/day of deferasirox, and studies are currently underway to assess the effectiveness and safety of higher doses; ñ Administration: Tablet dissolved in water (or apple juice), using a non-metallic stirrer. Taken once a day before a meal. ñ Continuous Monitoring ñ Use in children > 2 (FDA) and >6 (EMEA) years of age ñ Contraindicated in renal failure or significant renal dysfunction; ñ Cannot be given during pregnancy

Endocrine Complications In Thalassaemia Major

Endocrine abnormalities are among the common complications of thalassaemia. Despite early establishment of appropriate chelation therapy, problems such as delayed sexual maturation and impaired fertility may persist. Determining the prevalence of endocrine complications is difficult because of differences in the age of first exposure to chelation therapy, and the continuing improvement in survival in well-chelated patients. The growth rates and endocrine complications of a sample of 3,817 thalassaemia patients in 29 countries are reported in Table 1 (De Sanctis, 2004).

contributing factors to stunted growth in patients with thalassaemia may include chronic anaemia, transfusional iron overload, hypersplenism and chelation toxicity (DeSanctis, 1991). Other contributing factors include hypothyroidism, hypogonadism, growth hormone deficiency/insufficiency, zinc deficiency, chronic liver disease, undernutrition and psychosocial stress.

Diagnosis and investigations Diagnosis requires careful clinical evaluation to establish: 単 slow growth rates: growth velocity expressed in cm/year, below 1SD for age and sex (based on growth velocity charts) 単 short stature: height below the 3rd centile for sex and age (based on national growth charts) (see Appendix A) 単 signs of other pituitary hormone deficiencies (e.g., gonadotrophins) 単 other possible causes of retarded growth.

Growth Growth retardation is common in thalassaemia major. Patterns of growth are relatively normal until the age of 9-10 years when growth velocity begins to slow. Key

Short stature Primary hypothyroidism Insulin-dependent diabetes mellitus Impaired glucose tolerance Hypoparathyroidism Hypogonadism Growth hormone deficiency/insufficiency

males females males females males females males females males females males females males females

Based on a sample of 3,817 thalassaemia patients in 29 countries

Table 1: Growth and endocrine complications in thalassaemia

Number of patients 664 513 60 64 75 46 109 136 40 125 353 243 53 148

% 31.1 30.5 2.8 3.8 3.5 2.7 5.1 8 6.5 7.4 43.3 37.7 7.1 8.8

patients with thalassaemia receiving irregular transfusion, as well as in those regularly using desferrioxamine. In peri-pubertal patients, hypogonadism should be carefully investigated before starting growth hormone treatment which may result in decreased insulin sensitivity and abnormal glucose tolerance (de Sanctis, 1999).

Investigation of a child with thalassaemia who has stunted growth is generally similar to that of a child without thalassaemia. Evaluation of short stature/retarded growth.

The first step in the investigation of short stature or retarded growth is the regular (six-monthly intervals) and accurate measurement of standing and sitting height, pubertal staging (Tanner 1962) and bone age, including examination of metaphyses. Interpretation of absolute height must take into account the height of the parents.

Oral zinc sulphate supplementation should be given to patients with proven zinc deficiency.

Delayed puberty and hypogonadism Delayed puberty and hypogonadism are the most obvious clinical consequences of iron overload.

Additional endocrine studies that may be helpful include thyroid function tests (FT4, TSH), assessment of levels of sex hormones, growth hormone (GF) secretion, zinc, calcium, alkaline phosphatase, urine analysis, and investigation of glucose tolerance. Possibly useful tests include: Insulin Growth Factor-I (IGF 1) and Insulin Growth Factor Binding Protein-3 (IGFBP-3). The secretion of GH is normal in the majority of patients with thalassaemia. However, an investigation of transglutaminase antibodies is also essential, to exclude celiac disease.

Delayed puberty is defined as the complete lack of pubertal development in girls by the age of 13, and in boys by the age of 14. Hypogonadism is defined in boys as the absence of testicular enlargement (less than 4 ml), and in girls as the absence of breast development by the age of 16 (de Sanctis, 1995). Arrested puberty is a relatively common complication in moderately or grossly iron overloaded patients with thalassaemia, and is characterised by a lack of pubertal progression over a year or more. In such cases, the testicular size remains 6-8 ml, and breast size at B3 (see Table 2). In such cases annual growth velocity is either markedly reduced or completely absent (de Sanctis, 1995).

It is important to bear in mind that desferrioxamine toxicity is an important cause of delayed growth (see Chapter on Iron load and Iron Chelation) Treatment Anaemia, folate deficiency and hypersplenism are traditional causes of poor growth in

Penile development P1: Prepubertal

Breast development B1: Prepubertal

Growth of pubic hair PH1: Prepubertal

P2: Early puberty (enlargement of scrotum and testes, 4-5 ml, little or no enlargement of penis)

B2: Early puberty (breast bud stage)

PH2: Early puberty (sparse growth)

P3: Mid-puberty (enlargement of penis and further growth of testes, 8-12 ml, and scrotum)

B3: Mid-puberty (breast and areolar enlargement)

PH3: Mid-puberty (hair extends over the pubic junction)

P4: Advanced puberty (enlargement of penis in length and breadth. Increased pigmentation of scrotal skin and enlargement of testicles, 15-25 ml)

B4: Advanced puberty (areola and nipple project separately from the contour of the breast)

PH4: Advanced puberty (hair corresponds to adult growth but less extensive)

P5: Adult

B5: Adult PH5: Adult (Fully developed breast, the areola no longer projects separately from the breast contour)

Table 2: Pubertal assessment according to Tanner

Most women with thalassaemia major present primary amenorrhoea, with secondary amenorrhoea developing over time, particularly in poorly chelated patients. Ovarian function in such cases is generally normal but gonadotrophin response to Gonadotrophin-Releasing-Hormone (Gn-RH) is low compared to patients with normal menstrual cycles.

ñ ñ ñ ñ

Investigations ñ ñ ñ ñ

Routine biochemical analysis Bone age (X-ray of wrist and hand) Thyroid function (TSH and FT4) Hypothalamic-pituitary-gonadal function: Gonadotrophin-Releasing-Hormone (Gn-

RH), stimulation test for Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) Sex steroids (serum testosterone, serum 17-‚ Estradiol) Pelvic ultrasound to assess ovarian and uterine size Transglutaminase antibodies In selected cases, Growth Hormone (GH) stimulation test In selected cases, Insulin Growth Factor-I (IGF-I), Insulin Growth Factor Binding Protein-3 (IGFBP-3), plasma zinc

Treatment

The treatment of delayed or arrested puberty and of 66

It is important that the treatment of pubertal disorders is treated on a patient-by-patient basis, taking account of the complexity of the issues involved and the many associated complications.

hypogonadotrophic hypogonadism depends on factors such as age, severity of iron overload, damage to the hypothalamo-pituitary-gonadal axis, chronic liver disease, and the presence of psychological problems resulting from hypogonadism. Collaboration between endocrinologists and other doctors is critical.

Hypothyroidism This may occur in severely anaemic and/or iron overloaded patients, usually appearing in the second decade of life. The condition is uncommon in optimally treated patients (de Sanctis, 1995; Sabato, 1983).

For girls, therapy may begin with the oral administration of ethinyl estradiol (2.5-5 Ă&#x152;g daily) for six months, followed by hormonal reassessment. If spontaneous puberty does not occur within six months after the end of treatment, oral oestrogen is re-introduced in gradually increasing dosages (ethinyl estradiol from 5-10 Ă&#x152;g daily) for another 12 months. If breakthrough uterine bleeding does not occur, low oestrogen-progesterone hormone replacement is the recommended treatment.

Signs and symptoms Pre-clinical hypothyroidism is asymptomatic. In mild and overt hypothyroidism, symptoms such as growth retardation, decreased activity, above normal weight, constipation, reduced school performance, cardiac failure and pericardial effusion may be encountered. The incidence of hypothyroidism is slightly higher in females. Typically, the thyroid gland is not palpable, thyroid antibodies are negative and thyroid ultrasonography shows an irregular echo pattern with thickening of the thyroid capsule.

For delayed puberty in males, low dosages of intramuscular depot-testosterone esters (25mg) are given monthly for six months, followed by hormonal re-assessment. In patients with hypogonadotrophic hypogonadism, treatment at a dose of 50 mg per month can be continued until growth rates wane. The fully virilising dose is 75-100 mg of depot-testosterone esters every 10 days, administered intramuscularly. The same effects can be achieved with topical testosterone gel.

Annual investigation of thyroid function is recommended, beginning at the age of 12 years. Free T4 and TSH are the key investigations, and their interpretation, along with TRH test and TSH response, are shown in Table 3. Bone age may be helpful in evaluating hypothyroidism. The majority of patients have primary thyroid dysfunction. Secondary hypothyroidism caused by ironmediated damage of the pituitary gland occurs very rarely.

For pubertal arrest, the treatment consists of testosterone esters or topical testosterone gel, administered as for the treatment of delayed puberty and hypogonadotropic hypogonadism.

Hypo-thyroidism

Serum FT 4

Serum TSH

TSH Response to TRH Increased

Subclinical

Normal

Mild Overt

Marginally low Low

Marginally increased (TSH: 4.5-8mIU/l) Elevated Exaggerated Elevated Exaggerated

Treatment Observation

L-thyroxin L-thyroxin

KEY: FT4-free thyroxine; TSH-thyroid stimulating hormone; TRH-thyrotrophin-releasing hormone (adapted from Evered, 1973) Table 3: Hypothyroidism and its treatment

Abnormal thyroid function may be reversible at an early stage through intensive chelation, and good compliance.

The pathogenesis resembles type-2 diabetes, with differences in the age of onset (it may start early in the second decade of life) and slow progression of disturbances in glucose metabolism and insulin secretion.

Treatment depends upon the severity of organ failure. Sub-clinical hypothyroidism requires regular medical follow-up and intensive iron chelation therapy.

The type of glycaemia may be classified as diabetic, borderline or normal.

Treatment

ñ Diabetic type: Fasting Plasma Glucose (FPG) ≥7.0 mmol/l (126 mg/dl) and/or plasma glucose 2 hours after 75 g glucose load (2hPG) is ≥11.1mmol/l (200 mg/dl). A casual Plasma Glucose (PG) ≥11.1 mmol/l (200 mg/dl) also indicates diabetic type. The persistence of “diabetic type” indicates that a subject has diabetes. ñ Normal type: FPG <6.1 mmol/l (110 mg/dl) and 2hPG <7.8 mmol/l (140 mg/dl). ñ Borderline type: includes those who are neither diabetic nor normal types, according to cut-off values for venous PG measurements.

In patients with mild or overt hypothyroidism, L-thyroxine is given.

Impaired carbohydrate metabolism Impaired glucose tolerance and diabetes mellitus may be the consequence of ‚-cell destruction secondary to iron overload, chronic liver disease, viral infection and/or genetic factors.

Diabetes in thalassaemia is rarely complicated by ketoacidosis.

after the age of 16 (de Sanctis, 1995). The majority of patients show a mild form of the disease accompanied by paraesthesia. More severe cases may demonstrate tetany, seizures or cardiac failure.

Investigations Oral Glucose Tolerance Test (OGTT) should be performed annually from the age of puberty. For children, a dose of 1.75 g/kg (to a maximum of 75 g) is used for OGTT.

Investigations should begin from the age of 16 and should include serum calcium, serum phosphate and phosphate balance. In cases with low serum calcium and high phosphate levels, parathyroid hormone should also be evaluated. Parathormone may be normal or low, with low readings for 1,25 dihydroxycholecalciferol (vitamin D).

Treatment ñ Impaired glucose tolerance may be improved by a strict diabetic diet, weight reduction, where applicable, and possibly intensive iron chelation therapy ñ In symptomatic patients, insulin treatment is normally required but metabolic control may be difficult to achieve ñ Where hyperinsulinism is insufficiently managed by diet alone, acarbose may be a useful first-line therapy for glycaemic control ñ The role of oral hypoglycaemic agents remains to be fully determined

Bone radiology shows osteoporosis and malformations.

Treatment ñ Oral administration of vitamin D or one of its analogues. Some patients require high doses of vitamin D to normalise their serum calcium levels. This should be carefully monitored, as hypercalcaemia is a common complication of this treatment. ñ Calcitriol, 0.25-1.0 Ìg, twice daily, is usually sufficient to normalise plasma calcium and phosphate levels. Weekly blood tests are required at the start of treatment, followed by quarterly plasma and daily urinary calcium and phosphate measurements. ñ In patients with persistently high serum phosphate levels, a phosphate binder (other than aluminium) may be considered. ñ Tetany and cardiac failure due to severe hypocalcaemia require intravenous administration of calcium, under careful cardiac monitoring, followed by oral vitamin D.

Monitoring diabetes and its complications ñ Blood glucose (daily or on alternate days) ñ Ketones – check if blood sugar is above 250 mg/dl ñ Fructosamine estimation is more helpful than glycosylated haemoglobin levels ñ Urinary glucose is influenced by increased renal glucose threshold ñ Renal function (serum creatinine) ñ Serum lipids (cholesterol: HDL, LDL, triglycerides) ñ Urinary protein ñ Evaluation of retinopathy

Hypoparathyroidism Hypocalcaemia, due to hypoparathyroidism, is a recognised late complication of iron overload and/or anaemia and usually begins

Management of Fertility and Pregnancy in ß-thalassemia

gonadal axis (Chatterjee and Katz, 2000; Skordis, Christou et al, 1998). Also, the management during pregnancy are different in that TI patients have an increased thrombotic risk and need transfusion during pregnancy (Nassar, 2006), whereas TM’s, in addition to complications specific to iron overload, also face the risk of thromboembolism, particularly those with splenectomy and autoimmune antibodies.

Advances in the primary care of ‚thalassaemia major (HbTh) by optimal blood transfusion and chelation therapy have improved patient survival into adulthood. At the same time, patients’ quality of life has also increased significantly, and the expectation of having a family—an important dimension of quality of life—is consequently an important aspiration for many. Although spontaneous fertility can occur in well-chelated and -transfused patients with spontaneous puberty, the majority are infertile due to hypogonadotrophic hypogonadism (HH) consequent to transfusional haemosiderosis (Chatterjee and Katz, 2000) and need Assisted Reproductive Techniques (ART).

Management of fertility Although 80-90% of patients have HH, gonadal function is usually intact in the majority of patients, indicating that fertility is usually salvageable, i.e. ovulation in females and spermatogenesis in males can be induced by exogenous gonadotrophin therapy, ‘bypassing’ the H-P axis. However, other endocrine disorders, namely diabetes and hypothyroidism, may also influence the outcome of fertility treatment and need to be corrected by standard care. Successful spontaneous pregnancies, as well those resulting from the induction of gametogenesis, have been documented in HbTh females and males (Aessopos et al, 1999).

Planned pregnancy is essential both in spontaneous and ART conceptions, as HbTh pregnancies are high risk for the mother and the baby. However, these risks can be minimised through pre-pregnancy counselling with the haematologist, the reproductive medicine specialist, the cardiologist and the obstetrician, in conjunction with the specialist nurse.

Management of infertility requires a thorough work-up, including pre-pregnancy counselling of the couple (see below). Fertility assessment of patients with thalassaemia should also include evaluation of the partner according to standard criteria (see http://www.rcog.org.uk). The fertility options are dependent on two factors (a) partners’ carrier status and (b) site of damage to the H-P-G axis.

The management of patients of thalassaemia intermedia (TI) is similar to that of thalassaemia major (TM), with minor modifications. Older patients with thalassaemia major usually have hypogonadotrophic hypogonadism and are unlikely to conceive spontaneously, whereas patients with thalassaemia intermedia are potentially fertile with intact pituitary-

H-P damage, when gonadotrophins are pulsatile. But majority of patients with HH are apulsatile with functional gonads, and are therefore likely to benefit from HMG/HCG therapy with 80% success rate. Patients with endometrial damage respond better to IVF programmes. Induction of ovulation should only be undertaken by a specialist reproductive team, according to Human Fertilisation and Embryology Authority (HFEA) guidelines (Deech, 1998 review). Patients should be counselled regarding risk of hyperstimulation syndrome, multiple pregnancy, ectopic pregnancy and miscarriage. The risk of hyper-stimulation and multiple births can be minimised by vigilant monitoring of the induced cycle, followed up through, vaginal ultrasound scans. For such procedures, it is important to obtain the consent both and imperative of the patients and involved clinicians and carefully documented notes should be kept throughout. The regime to be followed will be dependent on the teamâ&#x20AC;&#x2122;s local protocol (See Figure 1 for an established protocol).

If both partners are homozygous for â&#x20AC;&#x161;thalassaemia, use of donor gametes, preferably donor sperm is the ideal option, as sperm can be more easily available from sperm banks, whereas the use of donor eggs is technically more complicated with an unpredictable success rate (Deech, 1998 review). If the partner is heterozygous, then Pre-implantation Genetic Diagnosis (PGD) is another option, where diagnosis can be made prior to conception. This method may be more acceptable to certain communities with religious beliefs against termination of affected pregnancy. Lastly, in patients with severe organ damage or where both partners have HbTh, another option may be adoption, where there is good family support.

Methods for induction of ovulation Induction of ovulation with pulsatile GnRH infusion is only possible at the early stage of FIGURE1

patients. The induction process must be undertaken according to HFEA guidelines, with an emphasis on consent and counselling (Deech, 1998 review) (See Figure 2 for an established protocol).

Key points in induction of ovulation: ñ Careful monitoring of the cycle by serial vaginal ultrasound scans ñ DFO should be continued until HCG is injected/biochemical pregnancy is confirmed ñ Luteal support with progesterone may be required ñ After a maximum of six cycles, reassess and refer for IVF

However, the recent advent of micromanipulation techniques such as intracytoplasmic sperm injection (ICSI) has improved conception rates, even in oligoasthenospermic patients. Therefore, sperm should be cryopreserved in all subjects unless azoospermic, to better preserved fertility and so the chance of conception. However, our recent literature on sperm DNA damage in HbTH (Perera, Pizzey et al, 2002) males raises anxiety about mutagenic risks in these individuals, especially after ICSI, where natural protective barrier against gamete selection during fertilisation is lost.

Induction of spermatogenesis The induction of spermatogenesis in male patients with thalassaemia is more difficult that the induction of ovulation in their female counterparts, with a success rate of 10-15% in moderate to severely iron loaded

FIGURE 2

INDUCTION OF SPERMATOGENESIS ñ Baseline testosterone and semen analysis ñ HCG 2000 units twice-weekly for 6 months ñ Monitor testosterone level ñ Repeat semen analysis-no sperm ñ Continue HCG with combined HMG 75 units three times weekly for additional 6 months ñ If semen analysis is satisfactory

SAVE

ñ If azoospermia persists, stop treatment

Pre-pregnancy counselling

before encouraging women with thalassaemia major to embark on pregnancy: cardiac impairment, liver dysfunction and the vertical transmission of viruses.

Before embarking on fertility treatment, it is important that patients and their partners attend pre-pregnancy counselling, which has a three-fold purpose (a) evaluation of eligibility, (b) physicians to review medications involved and (c) physician/s, patient and partner to discuss the risks associated with induced fertility and pregnancy.

1. The most important is cardiac function because cardiac complications remain the leading cause of death in both transfused and untransfused patients. The cardiac load is increased during pregnancy by at least 25-30% due to increased heart rate and stroke volume. This, along with iron load, has a real potential for premature death from cardiac failure. Therefore it is prudent that all patients with TM should have cardiac assessment by ECHO (Left ventricular ejection fraction >65%; fractional shortening >30%), by ECG, both at rest and with exercise, and by 24 hr tapes to check for rhythm disorders. If LV dysfunction can be demonstrated in patients under stressful conditions or if significant arrhythmias have occurred, then women should be strongly advised against planning pregnancies (Hui et al,

Evaluation of eligibility (Figure 3) Each patient should be assessed regarding suitability to embark on pregnancy with optimum outcome both for the mother and the fetus. There are at least 3 important factors that must be seriously considered

Figure 3

EVALUATION OF ELIGIBILITY FOR PREGNANCY ñ Heart: ECG, Echo, MRI ñ Liver: LFT, ultrasound, biopsy ñ Endocrine: diabetes, thyroid, parathyroid and ñ Risk of thrombo-embolism: thrombophilia screen ñ Viral infections: HBV, HCV, HIV, rubella ñ Bone health: Vitamin D, calcium, DEXA, x-ray ñ Iron overload: ferritin, liver and heart Fe ñ Ascertain hemoglobinopathy status of partner ñ Optimise lifestyle issues (smoking, etc).

Diagnosis and Management of Osteoporosis in â&#x20AC;&#x161;-thalassaemia). Patients should also be screened for diabetes, thyroid function, and acquired red cell antibody. Both partners should be screened for haemoglobinopathy.

2002). Most of the non-invasive cardiac investigations are relatively insensitive for detecting early cardiac loading. Modified MRI has recently been developed using gradient T2* measurements to quantify iron levels, and can accurately relate these to LV dimensions assessed using the same technique (Anderson et al, 2001). If the facility exists, cardiac MRI should be performed and the aim should be to have T2* closer to 20 ms.

Review of medications

2. Liver function should be evaluated by biochemical test while iron overload status by liver biopsy and MRI. Liver biopsy can also provide information on fibrosis and cirrhosis.

(Figure 4)

This is a good opportunity to review medications and to give advice to patients regarding diet, smoking and alcohol, and to commence supplements of folic acid, calcium and vitamin D. Patients on oral chelators (deferasirox or deferiprone) are recommended to switch to desferrioxamine prior to induction of ovulation/spermatogenesis (Singer and Vichinsky, 1999). Hormone replacement therapy should also be stopped at least 4-6 weeks prior to induction of gametogenesis. Bisphosphonate is contraindicated during pregnancy and breast-feeding, as both are states of considerable negative calcium balance. It is therefore prudent to ensure adequate calcium and vitamin D intake before and throughout pregnancy. Other medications that should be discontinued at least six months prior to fertility treatment include interferon, ribovarin and hydroxy urea. Hypothyroid patients receiving thyroid replacement therapy should receive increased doses, to ensure they are euthyroid. Hyperthyroidism is rare in patients with thalassaemia. However, if a patient is receiving an anti-thyroid drug such as carbimazole, this should be replaced by propyl thiouracil.

3. All patients should be screen for HIV, Hepatitis B, Hepatitis C and rubella. The opportunity should not be missed to ensure rubella immunity prior to pregnancy. If the patient is HIV positive and wishes to have a family, she should be advised of the usual recommendations for care which include appropriate antiviral agents, delivery by CS and the avoidance of breast feeding to reduce the risk of vertical transmission to <5% (RCOG clinical Green Top Guidelines, 2004). As regards Hepatitis C-positive cases, these women should be given a course of antiviral agents to attain Hepatitis C RNA negative status. 4. Before embarking on pregnancy, it is also important to establish bone heath by Xray of spine and DEXA scan of hip and spines (BMD score) and correction of osteoporosis/osteopenia by institution of appropriate therapy (see Chapter 6:

Figure 4

REVIEW OF MEDICATIONS PRIOR TO PREGNANCY ñ Stop HRT ñ Stop interferon, ribovarin, hydroxy urea ñ Stop bisphosphonates six months prior to fertility treatment ñ Switch from warfarin to heparin ñ Switch from oral hypoglycaemic to insulin ñ Switch from oral iron chelation to DFO ñ Review thyroid medication ñ Give calcium and vitamin D supplements ñ Start folic acid supplement to prevent neural tube defect

pregnancy. Serum ferritin is likely to alter by 10%, despite increase in frequency of blood transfusion (Aessopos, 1999; Tuck, 1998; Daskalakis, 1998; Butwick, 2005). The aim during pregnancy is to maintain pretransfusion haemoglobin concentration above 10g/dL (Aessopos, 1999).

Risks associated with pregnancy (Figure 5) All patients should be made aware that pregnancy per se does not alter the natural history of thalassaemia. If pregnancy is managed in a multidisciplinary setting, the foetal outcome is usually favourable with a slight increase in incidence of growth restriction (Aessopos, 1999; Ansari, 2006; Tuck, 1998). It has been shown that the risks of pregnancy-specific complications such as ante-partum haemorrhage and pre-eclampsia in thalassaemia are similar to the background population. It has also been shown that DFO is not required during pregnancy in patients that are not iron overloaded and that have adequate cardiac function prior to

Management of pregnancy (Figure 6) Once pregnancy is confirmed, the patient should be managed in a multidisciplinary team consisting of obstetrician, midwife, physician, haematologist and anaesthetist. The patient should be made aware that although pregnancy is high risk, the outcome is usually favourable (Aessopos, 1999).

Figure 5

Risks associated with pregnancy ñ Pregnancy does not alter the natural history of the disease ñ Requires intense/vigilant monitoring ñ Cardiac complications ñ Risk of pregnancy-specific complications same as background population ñ Risk of miscarriage same as background population ñ Risk of foetal malformation: no increase ñ Risk of foetal growth restriction: two-fold increase ñ Preterm labour risk: two-fold increase ñ Risk of transmission to the fetus/baby of Hepatitis B/C, HIV ñ Risk of iso-immunisation ñ Risk of pre-maturity and growth restriction is increased in multiple births

from mid-trimester (Nassar, 2006; Eldor and Rachmilewitz, 2002). Although there is a predisposition to venous thrombosis in postsplenectomy patients, no reports of thrombotic episodes have been reported in the literature (Tuck, 1998; Daskalakis, 1998). Folate demand in pregnancy is normally increased and this may be relevant in patients with thalassaemia due to bone overactivity. Regular folic acid supplementation is recommended in mothers with thalassaemia major to prevent superimposed megaloblastic anaemia, although this has only been demonstrated individuals with ß-thalassaemia minor (carriers) (Leung, 1989). If cardiac function deteriorates during pregnancy, DFO may be used, with caution, as evidence regarding

The main risk to the mother is cardiac complications, which can be minimised by ensuring optimal cardiac function before embarking on pregnancy. The key points include evaluation of cardiac function by ECHO, and of liver and thyroid functions, in each trimester. All patients should be screened for gestational diabetes at 16 weeks and, if normal, this should be repeated again at 28 weeks. Serial ultrasound scans from 24-26 weeks onwards must be undertaken to monitor foetal growth. In selected cases, particularly those with thalassaemia intermedia, thromboprophylaxis by low molecular weight heparin is required

After delivery, DFO can be recommenced but not oral chelating agents. Breastfeeding should be encouraged in all cases except in those who are HIV and/or hepatitis C RNApositive and/or HBsAg positive because of the risk of transmission via breast milk.

teratogenicity of DFO is equivocal (Singer and Vichinsky, 1999). As regards the newer oral chelating agents, data on fetotoxicity are lacking. However, the manufacturerâ&#x20AC;&#x2122;s product information for DFO includes risk of skeletal anomalies in animal pregnancies. Although there are currently no reports regarding human foetal anomaly from DFO, patients should be informed about this prior to its use during pregnancy.

All patients should be counselled regarding contraception. Intrauterine devices should be avoided because of risk of infection. Taking oestrogen-containing birth control pill is also not advisable because of the risk of thrombo-embolism (Orr, 1967). In most cases, progesterone-only pill or barrier methods are usually appropriate. Male patients with hypogonadotrophic hypogonadism are not fertile spontaneously and therefore contraception is not required. Calcium and vitamin D supplements should be continued during breast-feeding, however bisphosphonate therapy for osteoporosis should only be resumed after cessation of breastfeeding.

As regards the management of labour, if pregnancy is non-complicated, one could await the spontaneous onset of labour. But, similar to reported data, it is the authorsâ&#x20AC;&#x2122; experience that 80% of women with thalassaemia will require caesarean section (CS) because of higher frequency of cephalopelvic disproportion, largely due to short stature and skeletal deformity in this cohort, combined with normal foetal growth. It is desirable to use epidural anaesthesia for CS wherever feasible, to avoid the risk of difficult intubation associated with general anaesthesias due to severe maxillo-facial deformity in TM patients (Orr, 1967). Although most skeletal deformities are largely prevented by regular transfusion, spinal abnormalities associated with TM are relevant to regional blockade. Osteoporosis and scoliosis are common in TM, despite transfusion therapy (Borgna-Pignatti, 2006b). Patients with osteoporosis usually have vertebral bodies with reduced height and the segmental position of the conus may be lower than predicted (Borgna-Pignatti, 2006b). It is therefore important to correct osteoporosis prenatally by hormone replacement (and premidronate therapy), where required, to increase bone density so that spinal anaesthesia at CS becomes feasible.

Figure 6

Key points for pregnancy care ñ Check cardiac, liver and thyroid function once each trimester ñ Screen for gestational diabetes ñ Increase frequency of blood transfusion to maintain pre-transfusion Hb above 10 g/dL ñ Serial ultrasound scans to monitor fetal growth ñ Higher incidence of caesarean section ñ Encourage breastfeeding unless HIV positive and/or ∏CV RNA and/or HBsAg positive ñ Resume DFO after delivery ñ Discuss contraception, where appropriate ñ POP, barrier method ñ Avoid intrauterine device and oestrogen-containing preparations ñ Resume bisphosphonate after breastfeeding has ceased

Diagnosis and Management of Osteoporosis in â&#x20AC;&#x161;-thalasaemia

Osteoporosis is a skeletal disease characterised by low bone mass and micro architectural deterioration with a resulting increase in bone fragility and hence susceptibility to fracture (Sambrook, 2006). With increased life expectancy, osteopeniaosteoporosis syndrome (OOS) is a major cause of bone pain of hip and spine and fragility fractures especially of the lumbar spine which may be found in 70-80% adult patients with â&#x20AC;&#x161;-thalassaemia world-wide, accounting for significant bone morbidity (Chatterjee, 2001).

2003; Lasco, 2001). The diminished osteoblast function with reduced osteocalcin (Morabito, 2004) is accompanied by a comparable or even greater increase in osteoclast activity through RANK/RANKL/osteoprotegerin pathway as the final, dominant mediator (Voskaridou, 2003).

Diagnosis and investigations (Figure 1 and Figure 2)

Aetiology and pathogenesis

The commonest presentation is bone pain and backache with or without past history of fractures. Patients may also be asymptomatic in 20% cases.

Several studies have shown reduced bone mass in osteoporotic patients with thalassaemia (Chatterjee, 2000; BorgnaPignatti 2006b; Chan, 2002; Morabito, 2004; Voskaridou, 2003) but the underlying pathogenesis is still speculative. The causes of OOS in thalassaemia syndromes are multifactorial (Chatterjee, 2000), and include marrow expansion secondary to ineffective erythropoiesis (Borgna-Pignatti, 2006), anaemia , transfusional haemosiderosis (Borgna-Pignatti 2006) , delayed puberty (Chatterjee, 2000), use of deferioxamine (Voskaridou, 2003) or oral chelation agents for iron overload (Chan, 2002), multiple endocrinopathies such as hypogonadothrophic hypogonadism or primary hypogonadism (Chatterjee, 2000), low IGF1 (Lasco, 2002), low vitamin D levels due to aberrant vitamin D-PTH axis (BorgnaPignatti, 2006). Genetic factors, for instance, polymorphism of the VDR gene and COL 1 gene seem to play an important role in the development of low bone mass (BorgnaPignatti, 2006; Morabito, 2004; Voskaridou,

(A) DEXA Scan The diagnosis is best confirmed by bone mineral density (DEXA) according to WHO criteria (Figure 1). Although bone mineral density remains the best available noninvasive assessment of bone strength in routine clinical practice, many other skeletal characteristics also contribute to bone strength (Mahachoklertwattana 2003). These include bone macro architecture (shape and geometry), bone micro architecture (both trabecular and cortical), matrix and mineral composition, as well as the degree of mineralisation, micro damage accumulation, and the rate of bone turnover, which can affect the structural and material properties of bone which are complicated and difficult to assess in routine clinical practice (Sambrook, 2006).

Figure1

World Health Organisation (WHO) criteria for diagnosis of OOS Osteoporosis BMD > 2.5 SD below the young normal mean (T score) or Standard deviations in relation to patient’s age (Z score) Osteopenia BMD >1.5-2.5 SD below the young normal mean (T score)

Figure 2

List of investigations ñ Bone profile-serum Ca, PO4, 25(0H) vitamin D, PTH 24h urinary calcium. ñ Endocrine profile FSH, LH, E2/T, TFT ñ Liver function test ñ Spinal X-ray ñ DEXA-Spine-hip, radius, ulna-annually ñ Markers of iron overload

(B) Biochemical (D)MRI

All patients must have endocrine and bone profile including 25 (OH) vitamin D3, PTH, calcium, phosphate, liver function tests, (alkaline phosphate, ALT, bilirubin, albumin) FSH, LH, testosterone and oestradiol assays (Chatterjee, 2001; Chatterjee, 2000).

MRI of spine, if available, must be undertaken to determine extramedullary haematopoiesis, specially in TI patients and also to check for degenerative changes, skeletal dysplasia and disc prolapse.

(E) Assessment of iron load and chelation therapy (see Chapter 3: Iron

AP and lateral X-ray of the spine is important to rule out fractures even in asymptomatic patients who may have micro fractures.

Overload).

(2) Calcimimetics Vitamin D deficiency must be corrected (oral dose of 1000-1500 IU/day) and calcium supplementation (500 mg-1G orally/day) (Sambrook, 2006).

MANAGEMENT Principles of management of OOS are the same as other patients with osteoporosis due to other conditions (Sambrook et al, 2006). The aim is to improve BMD score and prevent/reduce future risk or fracture with/without offering pain relief in thalassaemia patients. General guidelines include assessment of other drugs, lifestyle issues, exercise and diet.

(3) Anti-resorption agents Bisphosphonates represent the biggest advance in the treatment of osteoporosis in the past decade in non-thalassaemic patients (Sambrook, 2006), with results of clinical trials showing reductions in the risk of vertebral fractures (40â&#x20AC;&#x201C;50%) and non-vertebral fractures (20â&#x20AC;&#x201C;40%), including hip fractures. Bisphosphonates, the potent inhibitors of osteoclast function, can be used as second line therapy in TM patients (non-responders or poor responders) and those without hypogonadism (TI) with encouraging results. Route of administration and dose: They can be given as pamidronate 1-2 mg/kg body weight once a month as IV infusion for 3-5 years (Chatterjee, 2001), orally as alendronate 70 mg orally per week (Borgna-Pignatti, 2006b) or zolandronic acid twoâ&#x20AC;&#x201C;three times per year (Mahachoklertwattana 2006). Daily alendronate and risedronate have reduced the risk of single and multiple spine fractures, asymptomatic (morphometric) and symptomatic spine fractures in women with bone mineral density T scores of less than -2.5 and one or more prevalent spine fractures (Borgna-Pignatti 2006b). Despite their impressive anti-fracture efficacy, several issues are now arising with respect to bisphosphonates including the risk of jaw osteosclerosis in long-term users (BorgnaPignatti 2006b).

(A) Therapeutic Options (Figure 3) Controversy exists regarding the best therapeutic option for osteopeniaosteoporosis. It is likely that the factors contributing to OOS in thalassemia intermedia (TI), while overlapped with those of thalassaemia major (TM) have a different emphasis with intramedullary expansion being more important and hypogonadism less important than in TM. The choice of therapy depends on the age of the patient, the type of thalassaemia including transfusion dependence, symptoms and severity of clinical presentation, the past history of type and number of fractures, previous therapy, presence of risk factors of nephrocalcinosis, associated hypogonadism, hyperparathyroidism. An ideal therapy should be safe and effective, able to correct the specific defect of bone remodelling unit, strengthen the bone and offer symptomatic relief. (1) Sex steroid replacement therapy In symptomatic or asymptomatic TM patients with proven OOS (DEXA scan) and hypogonadism, it is logical to correct hypogonadism first by sex hormone replacement therapy for at least two years (Chatterjee, 2001; Chatterjee, 2000; Lasco, 2001; Carmina, 2004).

(4) Combination therapy Combination of pamidronate to HRT regime in TM has been used with successful results (Chattergee et al, 2001).

treatment for >5 years is not recommended as it may induce osteosclerosis, specially of the jaw (Borgna-Pignatti, 2006) and may even aggravate the existing problem. Biochemical correction of hypogonadism must be confirmed from optimal peak and trough sex steroid levels. Caution must be exercised in prescribing vitamin D replacement therapy patients with risk of nephrocalcinosis and bisphosphonate is also given in caution (Borgna-Pignatti 2006). Patients on thyroxine and corticosteroid replacement therapy must be monitored carefully as excess replacement can aggravate osteoporosis.

(B) Monitoring of Treatment Treatment should be monitored with biochemical parameters (bone and sex steroid profile) and annual DEXA scan of spine and femoral neck to determine the T scores. A rise of 1-2% per year is expected in the femoral neck with or without change in femoral scores (Mahaklertwattana et al, 2003). After 3 years of pamidronate, usually the BMD effect plateaus. Also long-term

Figure 3

Recommendations ñ Diet and exercise ñ Vitamin D and calcium supplementation ñ Sex hormones replacement in HH-HRT ñ Anti-resorption agents-Bisphosphonate ñ Combination therapy-Bisphosphonate+HRT

The Management of Cardiac Complications in Thalassaemia Major

The quality and duration of life of transfusion-dependent patients with thalassaemia has been transformed over the last few years, with their life expectancy increasing well into the third decade and beyond, with a good quality of life (Olivieri 1995; Zurlo 1989).

prompt intervention. Ideally, a quantitative assessment of the degree of myocardial iron overload is required in order to identify those patients at risk of developing heart complications as well as, importantly, those where the risk may be minimal. Establishing the best treatment protocols requires co-operation between the treating physician and cardiologists experienced in dealing with cardiomyopathies.

Nevertheless, cardiac symptoms and premature death from cardiac causes are still major problems.

Iron related heart complications are the leading cause of death and one of the main causes of morbidity.

Clinical manifestations Patients with considerable iron overload of the heart may remain free of symptoms. Once myocardial dysfunction develops, discernible symptoms are related to the degree of ventricular impairment. Subtle early signs may be confused with the effects of the underlying condition.

In the absence of effective iron chelation therapy, many patients sustain iron-induced myocardial damage resulting in cardiac failure, cardiac arrhythmia, progressive congestive cardiac failure or sudden death (Brittenham,1994).

Even after significant effects on heart muscle, however, including symptoms of heart failure, aggressive iron chelation can restore myocardial function to normality.

For example, breathlessness during exercise may be attributed to anaemia. In more advanced stages of heart failure, clinical presentations are equivalent to those seen with any severe heart muscle disease and may include dyspnoea, peripheral oedema, hepatic congestion and severe exercise limitation. Signs and symptoms of right heart failure may predominate, but bi-ventricular involvement is the norm. The development of the signs of classical heart failure implies advanced disease with a poor prognosis, until the acute situation is resolved. As mentioned above, an important

The unique capacity of the heart to recover from the effects of iron overload only emphasises the importance of early detection and, ideally, prevention; once overt heart failure is manifest, acute survival may be as low as 50%.

The regular assessment of cardiac status helps physicians to recognise the early stages of heart disease and allows for

distinguishing feature of heart failure due to iron overload is the capacity of heart function to make a complete recovery with appropriate chelation therapyâ&#x20AC;&#x201D;a fact that may not be widely appreciated by physicians and cardiologists unaccustomed to dealing with patients with thalassaemia. It must be emphasised that the patient may require support of failing circulation for a period of several weeks in order to achieve a full recovery.

Treatment is directed towards the relief of iron overload, with a secondary strategy of symptomatic treatment of the documented arrhythmia.

Symptoms of palpitations are common in patients with thalassaemia, and are a frequent cause for anxietyâ&#x20AC;&#x201D;both for patients and their physicians. In brief, the prognostic implications of arrhythmia are related to the degree of myocardial iron-overload and any associated myocardial dysfunction. Thus in the case of a non-iron overloaded patient, the development of an arrhythmia such as atrial fibrillation (AF) deserves simple investigation and possible pharmacological treatment, but does not necessarily imply an adverse outcome. The same arrhythmia in a heavily iron overloaded heart, particularly if cardiac dysfunction is present, may be the harbinger of severe decompensation and requires immediate response and probable hospitalisation.

Patients frequently present with epigastric pain due to liver congestion, diminution in exercise capacity and also dyspnoea and cough.

Chest pain is uncommon in thalassaemia, but may accompany intercurrent illnesses including pericarditis or myocarditis. The frequency of these complications appears to differ between countries, being rare in the UK but more prevalent elsewhere.

Clinical examination A thorough medical history and physical examination are required for a basic cardiological assessment, which should also include: 12-lead electrocardiogram and a detailed echocardiogram, undertaken according to published guidelines. Where available, cardiac magnetic resonance imaging (CMR), used to quantitatively estimate cardiac iron overload, has become an invaluable tool in the estimation of clinical risk for the development of heart complications in thalassaemia. Additional tests may also be valuable for the detailed assessment of individual clinical problems, such as the investigation of cardiac arrhythmia (Holter or 24-hour ECG) or functional assessment by exercise tests.

Palpitations must therefore be investigated and treated in the context of the patient as a whole. Ectopic activity, usually supraventricular but occasionally ventricular, can produce symptoms requiring prophylactic drug treatment (often with beta-blockers), especially as these transient events can trigger more sustained arrhythmias, particularly AF. Arrhythmias that produce symptoms of haemodynamic compromise (dizziness, syncope or pre-syncope) pose a significant clinical risk and are associated with significant myocardial iron-overload.

Electrocardiogram The electrocardiogram is frequently abnormal, but changes are typically nonspecific. These changes commonly include depolarisation changes in the T-waves and ST segments of the anterior chest leads, and sometimes a preponderance of right ventricular voltages. Occasionally P-waves are

right and left heart dimensions, biventricular function (left ventricular fractional shortening and ejection fraction), estimated intracardiac pressures (pulmonary artery pressure, systolic and mean) and Doppler analysis of intra-cardiac flows. Longitudinal follow-up assessments should be carried out at approximately the same time in the patient’s transfusion cycle, to minimise variability of clinical parameters.

also affected, suggesting bi-atrial enlargement. Conduction disturbance in the forms of bundle branch block may be seen but higher degrees of conduction disturbance are rare. When new ECG abnormalities appear during follow-up, further investigation is required in order to detect the cause.

Ambulatory monitoring of ECG The standard method for detecting and investigating cardiac arrhythmia is via Holter ECG recording for 24 or more hours. There are now many types of recorders suited to the detection of intermittent cardiac arrhythmia.

Examination by echocardiography of the ventricular response to exercise may also be useful, highlighting individuals with subclinical disease in whom the ejection fraction fails to rise, or even falls, in response to exertion or simulated exercise using i.v. dobutamine.

Exercise ECG Exercise testing, by treadmill or cycle ergometer, may be of value in identifying patients at risk for cardiac arrhythmias or for assessing functional capacity. Adequacy of treatment of cardiac disease can also be gauged by exercise test performance.

Radioisotope studies: The use of MUGA (Multiple Uptake Gated Acquisition) to determine the overall left-ventricular ejection fraction is an outmoded technique (both in requiring the use of radioactive isotopes and its high cost). Greater accuracy can be achieved by monitoring resting ejection fraction and the response to a reproducible stress, in order to establish whether the ejection fraction can rise from its basal level.

An exercise test with gas-exchange evaluation allows verification of: VO2 peak (maximal O2 utilisation at the peak of the stress) and VO2 AT (anaerobic threshold), which are parameters closely related to the functional status and prognosis of patients with left-ventricular dysfunction.

Cardiac Magnetic Resonance Imaging (CMR)

The CMR scan provides a combination of morphological, functional information on the heart as well as—uniquely— quantitative estimates of tissue iron overload.

Echocardiography Echocardiography is widely available, relatively inexpensive and easy to perform. A large number of parameters can be obtained from the cardiac ultrasound investigation but even the simplest measurements of chamber size can provide immediate and valuable data on cardiac status and clinical progress, as long as they are obtained by a skilled practitioner following a standardised protocol. A minimum data set should include:

As a result, CMR is rapidly becoming the tool of choice in the clinical assessment of patients with thalassaemia and is hampered only by the limitation in access to appropriate scanners in some parts of the

measures, along with particular cardiological interventions. Such measures might include:

world. Scan times have been progressively reduced with modern protocols and very few patients are unable to tolerate the procedure due to claustrophobia.

ñ Maintenance of pre-transfusional haemoglobin level close to 9-10.5 g/dl in patients without heart disease, and 1011 g/dl in patients with heart disease; ñ Regular iron-chelation therapy and, for patients with high iron loads or cardiac disease, constant infusion regimens (s.c. or i.v.); consideration of combined chelation regimes using parenteral and oral chelators simultaneously. ñ Surveillance and adequate management of other causes of heart failure such as hypothyroidism, hypoparathyroidism, renal dysfunction, coincidental valve or structural heart disease, vitamin C deficiency. Avoidance of unhealthy life styles, including smoking, lack of physical exercise and excess alcohol consumption.

Cardiological management protocols The frequency of cardiological assessments described above depends on the age of the patient and a clinical assessment of the likely risk of significant myocardial iron overload, or awareness of high total body iron burden. ñ Well-chelated patients: first assessment at puberty, with repeat examinations yearly. The timing of a first CMR is not determined but should probably wait until the time of greatest actuarial risk, i.e. late teens to early 20s. ñ Asymptomatic patients with any evidence of cardiac impairment: every three to six months. An initial CMR will give evidence of specific myocardial iron burden, which may then be followed by repeat examinations at six to 12 months to ensure treatment strategies are associated with a fall in heart iron content (rise in CMR T2* parameter towards 20 msec). ñ Patients with symptoms of cardiac impairment: weekly to every one to four months, depending on clinical condition. An immediate CMR will help guide management while subsequent scans provide an indication of response to treatment.

Monitoring cardiac function can be a useful guide to a patient’s overall prospects. Impaired myocardial function may require specific cardiac treatment, but it also calls attention to the immediate need for much stricter adherence to chelation protocol or the initiation of a more intensive chelation programme, in order to prevent an inexorable progression to severe cardiac failure.

Specific Cardiological Care

The essence of treatment of cardiac disease should be aggressive chelation therapy to rapidly counteract iron toxicity and progressively remove excessive iron deposits (Davis and Porter 2000).

Overall Management Strategy The therapeutic strategy to diminish the risk of heart complications in patients with thalassaemia involves a number of general

(see Chapter 3: Iron Overload for details on

fibrillation.

designing an appropriate chelation programme under these conditions).

Diuretics are the mainstay in producing symptomatic improvement in those individuals who develop pulmonary congestion or signs of right-sided heart failure. Loop diuretics such as Frusemide and Bumetanide will produce a reduction in circulating volume, which may considerably decrease pre-load. These diuretics should therefore be used with caution in patients with thalassaemia. The tendency for patients with thalassaemia to have restrictive physiology, with diastolic heart failure, means that the reduction in pre-load due to a loop diuretic can produce a sudden fall in cardiac output. These effects may precipitate prerenal failure. To restate, loop diuretics should be used cautiously and mainly in the late stages of disease.

Over recent years there has been a trend towards treating patients with thalassaemia exhibiting mild ventricular dysfunction with agents known to improve myocardial function in other forms of cardiomyopathy. Treatment of myocardial dysfunction is best undertaken using angiotensin converting enzyme inhibitors (ACE inhibitors). In controlled trials, these agents have been shown to reduce mortality in patients without thalassaemia established cardiomyopathy and to reduce the rate of appearance of heart failure in those with asymptomatic left-ventricular dysfunction. These results are very promising, and while their extension to heart failure in thalassaemia remains conjectural, it is widely applied in clinical practice. The usual precautions for initiating treatment in patients who are well hydrated and starting at low doses are recommended. The dose should be increased to the maximum tolerated, limited by hypotension in patients with thalassaemia. Certain patients are unable to tolerate ACE inhibitors due to the development of chronic cough. These individuals should be treated with angiotensin II receptor antagonists, such as losartan. Even though support for this drug in cardiac failure is not strong at present, the haemodynamic profile approximates that of ACE inhibitors.

Recent evidence supports the use of spironolactone as adjunctive treatment in non-thalassaemic patients with cardiac failure. This and related agents reduce potassium depletion induced by loop diuretics and counteract hyperaldosteronism. Potassium sparing agents can be used with ACE inhibitors, but require careful monitoring of electrolytes. When dealing with severe congestive cardiac failure in hospital, it is advantageous to use constant intravenous infusions of loop diuretics. This aids careful titration of the doses of diuretic on an hour-to-hour basis, according to urine output, thus avoiding the dangerous situation of massive diuresis, volume depletion, fall in cardiac output and worsening of renal function that can follow large i.v. bolus doses of loop diuretics. Inotropic support may be indicated in severe cases. Managing such patients can be aided by

Digoxin should not be used in the early stages of cardiomyopathy but may have a role as an inotropic agent in patients with cardiac dilatation accompanied by low blood pressure. Digoxin has a very specific role in the maintenance of reasonable ventricular rates in patients with established atrial

treatment of AF.

utilising biochemical markers of heart failure (BNP or pro-N-terminal BNP). Values are high in decompensated heart failure and fall in response to treatment. Data support delaying hospital discharge in decompensated heart failure until BNP levels have reverted to normal.

Amiodarone has a very wide spectrum of effectiveness against supraventricular and ventricular arrhythmias and produces a survival benefit in non-thalassaemic individuals with life-threatening ventricular dysrhythmias. However, Amiodarone does have an enormous potential for side effects, one of whichâ&#x20AC;&#x201D;disturbances of thyroid functionâ&#x20AC;&#x201D;is of particular relevance in patients with thalassaemia.

Anti-arrhythmic agents: In many instances, the use of drugs to treat relatively benign but symptomatic arrhythmias may produce greater morbidity and mortality than in untreated individuals. The decision to treat arrhythmias in patients with thalassaemia must therefore be carefully considered, bearing in mind that iron toxicity is the primary cause of this complication. Intensive chelation treatment has been demonstrated to reduce arrhythmias. In the majority of instances, the arrhythmias are supraventricular, although ventricular tachycardia may occur in seriously ill individuals. The development of arrhythmia may be associated with a deteriorating ventricular function, and can be improved by addressing the latter problem. Overall, arrhythmias require very careful assessment. For most supraventricular arrhythmias, reassurance of the patient is generally appropriate, whereas patients with ventricular arrhythmias require urgent attention to address associated high myocardial iron load, via intensified chelation.

The role of other drugs, such as calciumantagonists and class I antiarrhythmic agents, has yet to be established. Generally, these agents should be avoided, since they all have a tendency to produce negative inotropic effect. Their use has not been widespread, since arrhythmias tend to be associated with more severe levels of myocardial impairment. Without more formal study, the use of such drugs cannot yet be recommended for the treatment of patients with thalassaemia. Cardioversion should be considered in patients who fail to respond to iron chelation therapy and pharmacological intervention. In the situation of acute heart failure, cardioversion from AF to normal rhythm should be considered early on, as reestablishing synchronised cardiac conduction improves cardiac failure.

Anti-coagulation: All patients with in dwelling central venous lines require formal anti-coagulation with warfarin or other suitable Coumadin derivatives, to prevent the potentially life-threatening complication of intra-atrial thrombus formation with embolisation and the development of pulmonary hypertension. Patients in AF also should be considered for anti-coagulation, if only as a temporary measure prior to

Beta-blocking agents can also be used to control many arrhythmias, and are indicated in patients with stabilised heart failure as they improve the medium- to long-term prognosis. Dosages should be low at first with careful slow upward titration over days and weeks. In heart failure, Carvidelol and Bisoprolol have a special role, while Sotalol may have advantages for the prophylactic

with or without symptoms: ñ intensification of iron chelation: i.v. desferrioxamine (24 hours x 7 days/week); consider combination treatment with oral deferiprone and s/c desferrioxamine ñ slow blood transfusion with diuretics ñ specific cardiac medications: ñ ACE inhibitors, or ARII blockers where ACE not tolerated ñ beta-blockers: carefully introduce once acute heart failure stabilised; bisoprolol or carvidelol remain first choice ñ diuretics, for the symptomatic relief of fluid overload; use sparingly whilst monitoring renal function; spironolactone should be introduced if possible ñ digitalis, if in atrial fibrillation, Warfarin: if central line in situ, or if in AF

cardioversion.

Heart transplant: A few patients have undergone heart transplant for severe, irreversible cardiac damage, and this procedure has also been combined with liver transplant (Olivieri, 1994). The outcome of transplant in patients with thalassaemia needs to be carefully studied to determine the effectiveness of this approach. The presence of iron-induced damage to other organs may adversely affect the outcome of heart transplant. If surgery is successful, intensive chelation therapy is still required to remove iron from other organs and to prevent iron accumulation in the transplanted heart.

Summary A) For asymptomatic patients with a normal heart and no myocardial iron content by CMR (or, where no CMR is available, patients with proven good chelation records and an absence of iron-related complications): ñ encourage continuation of current, effective chelation ñ encourage maintenance of a healthy lifestyle

Conclusion The prospects for patients with thalassaemia have improved with a greater understanding of the disease and with better, individualised regimes of management. Close co-operation between the medical disciplines is called for. At the same time, the fundamental treatment aim remains to provide regular, effective iron chelation, in forms that encourage patients to comply with treatment—treatment that must be allied to more precise definition of tissue-specific iron loads, so that patient and physician alike have a better idea of individualised risk.

B) For patients with increased cardiac iron content (measured by CMR) but normal cardiac function (or, where no CMR is available, those with iron related complications and/or a poor chelation history): ñ intensification of iron chelation: s.c. or i.v. desferrioxamine (24 hours x 7 days/week); consider combination treatment with oral deferiprone and s/c desferrioxamine ñ as for group A C) For patients with cardiac impairment,

in TI. According to this study, moderate to severe PHT was observed only in TI patients with a prevalence of 23%. Systolic left ventricular dysfunction, in contrast, was present only in TM cases with a prevalence of 8%. Heart failure was observed in 3% of TI patients and 4% of TM ones.

The prevalence, pathophysiology, diagnosis and management of pulmonary hypertension in â&#x20AC;&#x161;-thalassemia

In terms of pathophysiology, it seems that PHT in â&#x20AC;&#x161;-thalassemia results from a rather complex combination of mechanisms, which lead to the increase of both cardiac output and pulmonary vascular resistance. Chronic tissue hypoxia and chronic hemolysis are believed to hold the central pathogenetic role, while individual mechanisms involved include the prolonged anemic state, the increased percentage of hemoglobin F, the hepatic abnormalities, the presence of a hypercoagulabilable state, the thalassemiarelated elastic tissue defects, and the coexistent endothelial dysfunction (Aessopos, 2007).

Cardiac involvement represents the primary cause of mortality in both thalassemia major (TM) and thalassemia intermedia (TI). In this context, pulmonary hypertension (PHT) is part of the cardiopulmonary complications of the disease (Aessopos, 2005). Pulmonary hypertension was initially documented in a small group of 7 TI patients with right heart failure (Aessopos, 1995). In a subsequent study (Aessopos, 2001) of a large 110-patient series, age-related PHT was found in nearly 60% of cases followed by right heart failure in 5% of patients. It should be noted that all those patients had preserved left ventricular systolic function and normal pulmonary capillary wedge pressure. Thus, following those observations PHT is currently considered to be the primary cause of heart failure in TI patients.

The diagnosis of PHT in patients with thalassaemia may be performed simply and non invasively using transthoracic Doppler echocardiography (Aessopos, 2000). It has been shown that a peak systolic tricuspid pressure gradient in the presence of tricuspid regurgitation higher than 30 mmHg is indicative of the presence of pulmonary hypertension. A follow-up strategy with clinical examination of the cardiovascular system, electrocardiography, chest X-ray and echocardiography, performed on an annual basis, or in shorter intervals if clinically indicated, should be applied in every patient with thalassaemia. A close collaboration between attending physicians, hematologists and cardiologists is required in this context. Although both forms of the disease share a common molecular background, the diverse severity of the genetic defect and of the

In what concerns the development of PHT in TM, a recent study (Aessopos, 2007) compared cardiac disease between two large aged-matched groups of TM (n=131) and TI (n=74) patients, both treated uniformly in the currently accepted manner, namely regular transfusion and chelation therapy in TM and absence of any particular treatment

resulting clinical phenotype impose a different therapeutic approach. The currently applied regular lifelong therapy in TM patients eliminates chronic hypoxia and thus prevents the development of PHT. On the other hand, the absence of systematic treatment in TI leads to a cascade of reactions that compensate for chronic anemia but at the same time allow the development of PHT. The accumulated experience indicates that a large number of TI patients, if not the majority of them, should be considered for regular transfusion and chelation therapy (Aessopos, 2007). Two crucial points that remain to be clarified are the patient selection criteria and the timing of treatment onset. Until research data becomes available, the judgement should be based on individual clinical and laboratory assessment of patients. The applied treatment, once started, should definetely aim at prevention and not palliation of anaemia-induced complications.

The Liver in Thalassaemia

overload (HIC in mg/g dry weight x 10.6 = whole body iron store in mg/kg) (Angelucci, 2000). Non-invasive techniques used to assess hepatic iron include computed tomography, biomagnetic liver susceptometry (SQUID) and magnetic resonance imaging (MRI). Of these, relaxation rates R2 (1/T2) and R2* (1/T2*) measured by MRI appear to be the most promising and accurate (Wood, 2005).

Under normal circumstances, about one-third of storage iron (ferritin and haemosiderin) in the body is found in the liver. Approximately 98% of hepatic iron is found in hepatocytes, which make up 80% of total liver mass; the remaining 1.5-2% of total liver iron is found in reticuloendothelial cells, endothelial cells, bile ductular cells and fibroblasts. Iron that enters the cell in excess of that required accumulates in the major storage forms of iron, ferritin, and haemosiderin. Progressive accumulation of storage iron is associated with cellular toxicity, although the specific pathophysiologic mechanisms for hepatocytes injury and liver fibrosis are not entirely understood. These include lipid peroxidation of organelle membranes, increased lysosomal fragility and decreased mitochondrial oxidative metabolism. Iron also has a direct effect on collagen synthesis and/or degradation, and alterations in microsomal enzymes.

Hepatic iron stores are closely correlated with cumulative transfusional iron load and have been used as a marker for the effectiveness of chelation therapy and prognosis. An increase in hepatic iron is associated with an increased risk of impaired glucose tolerance, diabetes mellitus, cardiac disease and death.

The liver plays a central role in iron homeostasis. In addition to iron released from transfused red cells, an enhanced rate of gastrointestinal iron absorption has been suggested. This excess iron is initially confined to the Kupffer cells but when transfusion requirements produce massive iron overload, spillover to hepatic parenchyma cells quickly occurs, with the risk of late development of fibrosis and cirrhosis. In patients with â&#x20AC;&#x161;-thalassaemia, in absence of co-factors, the threshold hepatic iron concentration for the development of fibrosis is about 16 mg/g dry weight liver (Angelucci, 2002). Clinical studies suggest a relationship between hepatic iron concentration and the development of ironinduced hepatotoxicity.

Hepatitis C Virus (HCV) This RNA virus was first characterised in 1989, having previously been termed non-A non-B hepatitis. The majority of HCV isolates studied so far can be divided into six major groups, designated genotypes 1-6, with subdivisions in each (subtype a, b, c, etc.). Antibodies that develop after infection are not protective but rather are indicative of current or past infection. Active infection is diagnosed by the presence of circulating HCV RNA in blood (Sharara, 1996)

Hepatic iron concentration (HIC) is the gold standard for the measurement of body iron

Reversibility: The reversibility of advanced fibrosis and even early cirrhosis (Child A â&#x20AC;&#x201C; compensated or well-compensated*) has been documented in thalassaemia once causes of liver injury (iron overload and HCV infection are removed) (Muretto, 2002).

Preventative measures to minimise the risk of posttransfusional hepatitis C include careful selection of voluntary donors and appropriate blood donor screening.

End-stage liver disease: should lead to consideration of liver transplantation. Hepatitis C is currently the commonest reason for liver transplantation worldwide. Recurrent hepatitis C infection occurs in > 90% of cases after transplant but is usually mild. Long-term survival after liver transplantation for hepatitis C is similar to that for other diagnoses, averaging 65% after 5 years (Gane, 1996).

Natural history and complications of infection Acute infection: generally benign, with >80% asymptomatic. Anicteric Fulminant Hepatitis is very rare.

Hepatocellular carcinoma (HCC): Chronic infection: develops in 70-80% of

develops in 1-5% of infected individuals after 20 years, particularly after the development of cirrhosis, increasing by 1-4% each year thereafter (Colombo, 1991). Prevention and early detection of HCC are more effective than attempted cure. Cirrhosis patients should undergo a regular six-monthly screening programme, including liver ultrasound examination and alpha-fetoprotein check, for the early detection of hepatocellular carcinoma.

cases, leading to chronic liver disease. However, the clinical outcome is highly variable, for reasons that are not completely understood. Determinants of disease severity or chronicity as well as response to therapy include age at acquisition, as well as hostspecific (e.g. immunity) and virus-specific (e.g. genotype) factors and, most important, co-morbidities.

Cirrhosis: develops in a variable percentage of HCV-infected patients, ranging from < 5% in young, healthy people, to approximately 25-35% of cases of patients with relevant comorbidities. Age and co-morbidities appear to be the most important factors affecting the risk of developing cirrhosis. Cirrhosis usually takes as long as two to three decades to develop from the time of acquisition. Fiveyear survival in patients with compensated cirrhosis is 91%, with a 79% rate of 10-year survival. When cirrhosis is decompensated however, 5-year survival falls to just 50%.

Extra-hepatic manifestations of HCV infection include porphyria cutanea tarda, essential mixed cryoglobulinemia, glomerulonephritis, autoimmune thyroidits and vasculitis (Sharara, 1996).

* Liver cirrhosis is divided to 3 stages following the Child-Pugh score, Score 5-6 (Score A) is characterised by: No ascites, Bilirubin < 2mg/dl, Albumin>3.5g/dl. INR <1.7, no encephalopathy. Therefore, Child-Pugh stage A can be defined as â&#x20AC;&#x153;well compensated diseaseâ&#x20AC;?.

to guide decisions on therapy and anticipate complications (Angelucci, 1995).

Special features of hepatitis C in thalassaemia major

Treatment This is a rapidly changing field and the treatment of hepatitis in patients with thalassaemia should therefore be undertaken in close collaboration with a specialist in liver disease.

The severity of chronic hepatitis C in patients with thalassaemia may be greater because of concomitant iron overload, other concurrent viral infections (HBV, HIV) and possible infection with mixed hepatitis C genotypes. It has been demonstrated that iron and HCV infection are independent but mutually reinforcing risk factors for the development of liver fibrosis and cirrhosis, with a reciprocal multiplicative effect (Angelucci, 2002). It appears therefore that patients with thalassaemia, particularly those with poor control of iron overload, face an increased risk of developing cirrhosis.

Similar to non-thalassaemia patients, treatment of HCV in patients with thalassaemia is aimed at eradication of the virus, improvement in liver histology, reduction of the risk of liver cirrhosis and hepatocellular carcinoma.

Selection of patients for therapy Patients diagnosed with acute HCV infection and persistently positive serum HCV RNA after 12 weeks of exposure or diagnosis should receive treatment (Sharara, 2006).

Diagnosis and monitoring

Initiation of treatment in chronic hepatitis C has traditionally been based on one or more of the following: 単 confirmed presence of HCV-RNA 単 moderate to high serum ALT levels 単 abnormal liver histology

Antibody testing This is most valuable for screening blood and blood products and as initial testing in patients with chronic unexplained elevation in serum transaminases or those suspected of having chronic liver disease. Confirmatory testing is done using HCV RNA detection by polymerase chain reaction (PCR), the current standard for the confirmation of viremia. Ascertaining the genotype and quantity of HCV RNA in serum is useful only in determining the type and duration of treatment (see below).

Encouraging results for the treatment of HCV in thalassaemia, combined with the abovementioned risks of greater severity of chronic hepatitis C in such patients, means that the presence of serum HCV-RNA alone is sufficient to consider treatment in patients with thalassaemia, where the patient has no other contraindications to treatment or other significant co-morbidities.

Liver biopsy in thalassaemia major Liver biopsy prior to treatment is helpful in determining the extent of liver damage and

Response to treatment Depending on HCV genotype and viral load,

ñ High baseline HCV-RNA level and the absence of its early decay (4-12 weeks) upon initiation of treatment ñ HCV genotypes 1 or 4 ñ Presence of bridging fibrosis or cirrhosis ñ Co-existence of other viruses (HBV, HIV)

40-80% of patients with chronic hepatitis C will respond to the current standard treatment of pegylated interferon and ribavirin. Response is defined on the basis of a negative highly sensitive qualitative HCV RNA PCR assay, carried out 24 weeks after completion of therapy.

Controversial in this specific setting is the role of iron overload.

Patient responses are classified as follows: ñ Early viral response (EVR): defined as an undetectable HCV RNA or a > 2-log reduction in viral load after 12 weeks of treatment ñ Response at end of treatment (ETR): defined as absence of HCV-RNA at the end of treatment ñ Sustained viral response (SVR): absence of HCV-RNA > 6 months after concluding treatment. This is in practice equivalent to viral eradication of HCV ñ Non-responders: lack of significant decline (defined as > 2-log reduction from baseline) in HCV RNA after 12 weeks of therapy ñ Relapsers: re-emergence of HCV-RNA after a satisfactory end of treatment response

Since no baseline factor is specifically predictive of treatment success or failure, withholding therapy on the basis of factors suggesting a poor response is unwarranted. Because of the possible role of iron overload in reducing the likelihood of successful treatment of hepatitis C and for general, well-known clinical reasons, effective chelation therapy should be strongly considered before initiation of antiviral therapy in patients with bad control of transfusional iron.

Treatment regimens The gold standard is combination therapy with pegylated interferon and ribavirin. An example of an algorithm used for Hepatitis C managament is presented in Figure 1.

Monitoring response Depending on HCV viral genotype, the current recommendation is to measure the biochemical (serum ALT) and virological (HCVRNA) response after 4 to 12 weeks of therapy, and to continue therapy for an additional 12 to 24 weeks in patients with undetectable HCV-RNA. Because serum ALT may be raised for other reasons in patients with thalassaemia (iron overload, concomitant infections), monitoring response is based on viral HCV RNA.

Type of interferon: Pegylated interferon ·-2a or ·-2‚ given subcutaneously once weekly Duration: 24 to 48 weeks, depending on genotype

Side effects: Typical side effects in most patients include flu-like symptoms, insomnia, and cognitive and mood changes, especially in the first two weeks after starting interferon. Dose-dependent neutropenia and thrombocytopenia commonly occur during

Prediction of poor response Negative predictors in all patients with hepatitis C are:

Figure 1

In thalassaemia major this may be associated with a more marked haemolysis and a 30% increase in transfusion requirement, which requires careful adjustment of the transfusion interval and intensification of iron chelation therapy (Li, 2002; Inati, 2005).

interferon therapy. Particular attention should be paid to this complication in patients with thalassaemia and hypersplenism. Since both deferiprone and interferon may cause neutropenia, there are theoretical risks associated with their combined use, and this combination should be initiated with caution and under careful monitoring. Hypothyroidism is an important complication of interferon treatment.

It is important to note that dose-reduction of ribavirin is associated with an inferior sustained viral response and it is hence recommended that transfusion-chelation requirements be adjusted to compensate for ribavirin-associated haemolysis rather than altering the recommended ribavirin dose (Inati, 2005).

Some patients have experienced exacerbation of local reactions at the site of desferrioxamine infusion during interferon treatment. Heart failure has been seen in a few patients with thalassaemia receiving interferon, and special care should be given if prescribing interferon for patients with pre-existing heart disease.

Treatment duration and viral load monitoring: Depends primarily on the HCV genotype. For genotypes 1 or 4, treatment is administered for 48 weeks provided there is a positive early viral response (EVR) at 12 weeks. In the absence of EVR, treatment is usually discontinued and further treatment options considered.

Monitoring for side effects: Close monitoring for hypothyroidism is mandatory in patients receiving interferon, and testing for thyroid function and the presence of anti-thyroid antibodies should precede initiation of therapy. Regular monitoring of blood counts is also necessary, to identify neutropenia or thrombocytopenia. Cessation of therapy should be considered if the absolute neutrophil count falls below 1,000.

This approach has been validated in patients with thalassaemia where an SVR of 64% is seen in patients infected with genotype 1 and 4 and who have exhibited an undetectable HCV RNA at 12 weeks of treatment (Inati, 2005). For genotypes 2 or 3, treatment is limited to 24 weeks. Given the high rate of SVR for genotypes 2 and 3, approaching 80%, a 12-week determination of viral load is not usually necessary.

Ribavirin is a nucleoside (guanosine) analogue, well absorbed orally, and typically given in doses of 800-1200mg/d. Alone, it has limited antiviral activity in hepatitis C but in combination therapy with interferon has been shown to significantly increase sustained response rates compared to interferon alone.

Treatment options for nonresponders These have not been firmly established and are currently considered experimental. An expedited second treatment option may need to be considered in patients with advanced fibrosis on liver biopsy.

Side effects: Haemolysis occurs in most patients without thalassaemia, with a decrease in haemoglobin of 10-20% from baseline levels.

Management of special patient populations

HBsAg, and other public health measures, have led to a significant reduction in hepatitis B infections in most countries of Europe and North America, as well as other parts of the world. Hepatitis B nevertheless remains a formidable medical problem, mainly in developing countries.

Consultation with a physician experienced in the management of liver disease is especially important in the clinical management of the following patient populations: ñ Children ñ Patients with cirrhosis ñ Immunosuppressed patients ñ Pregnant patients ñ Patients with acute hepatitis C

Prevention There is currently no vaccine or immunoglobulin to prevent hepatitis C. The following recommendations are made to reduce the risk of non-parenteral transmission:

Current HBsAg positivity in thalassaemia major ranges from <1% to >20% and Hepatitis B infection remains a significant cause of chronic liver disease and hepatocellular carcinoma in patients with thalassaemia in many regions of the developing world.

Sexual transmission risk is generally low. However, insufficient data exist to recommend changes in current recommendations: that patients encourage their sexual partners to be tested for hepatitis C, and that safe sexual practices should be encouraged.

Clinical significance of HBV markers Despite the availability of good screening tests for hepatitis B, the interpretation of results may be difficult or misleading.

General measures, such as avoiding sharing toothbrushes, razors, etc. are advised, to avoid transmission to family members. However, the risk of transmission is low, and special measures such as to segregate towels and eating utensils are probably unnecessary.

ñ Acute infection. HBsAg is a reliable marker (can be present for 4-5 months). HBeAg is also transiently present (1-3 months). Anti-HBc IgM is the most reliable test for the diagnosis of acute HBV infection. ñ Chronic infection (overt carrier) is marked by the presence of HBsAg and anti-HBc in the blood (usually accompanied by HBeAg or anti-HBe). In accordance with international definitions, overt carriers can be classified as:

Hepatitis B Virus (HBV)

ñ active carriers, identified by the presence of HBeAg or anti-HBe antibodies and a viral load ≥5 log10 copies/ml (although others cite a figure

Incidence

Vaccination strategies, screening of blood donors for 98

interpretations of screening results.

of ≥4 log10 copies/ml), corresponding to about 17,200 IU/ml, according to most recent standardisations. The great majority of active carrier cases are associated with the presence of hepatic disease.

Natural history Acute hepatitis: This is the most common presentation, with an incubation period of 420 weeks. Severity is variable, with an icteric period often preceded by a prodromal illness with arthralgia and urticaria. Progression to fulminant hepatic failure is rare (≤1%). Acute hepatitis B is usually managed by supportive measures alone.

ñ inactive carriers, characterised by the persistent normality of transaminase in an anti-HBe-positive subject, associated with levels of viremia below the threshold (<5 Log10) and, eventually, with IgM anti-HBc <0.2 IMx Index. In the majority of such subjects, the histological finding, when available, does not reveal significant liver disease (necroinflammatory activity <4 HAI), while in a small minority of cases it is possible to observe effects of a chronic (sometimes even cirrhotic) disease which have became silent spontaneously or thanks to the effect of the antiviral treatment. ñ

Progression to chronic hepatitis B occurs in 5-10% of otherwise healthy adults and in 90% of neonates. In acute icteric hepatitis B in adults, transition to chronicity appears to be rare, probably occurring in less than 2% of cases. For patients with chronic hepatitis B infection, co-infection with hepatitis C may increase the severity and rate of progression of liver disease.

previous infection: the presence of anti-Hbc antibodies ± anti-Hbs indicates previous infection. In particular circumstances, such as deep immunosuppression (i.e. hemopoietic stem cell transplantation), the possibility of HBV reactivation after a previous infection has been demonstrated. This category of patients can therefore also be defined as potential occult carriers (Marzano, 2007).

Cirrhosis occurs at a rate of 1-2.2% per year. Iron loading in thalassaemia may increase the risk, as may concomitant HCV infection. Hepatocellular carcinoma is a wellrecognised complication of chronic hepatitis B infection.

vaccination: the presence of HBsAg antibodies (if anti-HBc is not present) indicates vaccination.

Patients with thalassaemia should be screened for all serological markers of hepatitis B and classified according to Table 1, which provides a list of possible

Test

Results

HBsAg anti-HBc anti-HBs

HBsAg anti-HBc

+ + or -

Interpretation

Recommendation

Susceptible to infection/never exposed to virus

Consider vaccination

Acute or chronic infection

Further evaluation

HBsAg anti-HBc anti-HBs anti-HBeAg

+/+ -

Resolution of previous infection

HBsAg anti-HBc anti-HBs anti-HBeAg

+/-

Past infection*- potential occult carrier.

HBsAg anti-HBc anti-HBs HBeAg

+ + +

Carrier with chronic infection (if HBsAg+ 6 months or more) Highly infectious

Further evaluation, including HBV-DNA levels

HBsAg anti-HBc anti-HBs HbeAg Anti-HBe

+ -

Carrier with chronic infection (if HBsAg+ 6 months or more)

Further evaluation, including HBV-DNA levels

HBsAg anti-HBc anti-HBs HBeAg Anti-HBeAg

+ -

Immunisation without infection

* Other interpretations include: 1. Recovering from acute HBV infection, with loss of HBsAg but anti-HBs has yet to appear (“window period”). 2. Immune to HBV but anti-HBs never appeared or has fallen below the level of detection. 3. Chronic HBV infection with undetectable serum levels of HBsAg. 4. False positive anti-HBc, with susceptibility to HBV infection. * Interpretations 2 and 4 are the most common explanations of this serologic pattern.

Table 1: Possible interpretations of Hepatitis B screening results

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Prevention:

HBV 2007 Treatment Overview (Hepatitis Annual Update 2007

Vaccination: All newly diagnosed patients with â&#x20AC;&#x161;thalassaemia should be vaccinated against hepatitis B. Three injections (at 0, 1 and 6 months) are required to produce an antibody response in 95% of normal individuals. The vaccine is ineffective in those already exposed to hepatitis B.

website:http://clinicaloptions.com/Hepatitis/AnnualUpdates)

The primary goal of therapy for Chronic Hepatitis B (CHB) is long-term suppression of serum HBV-DNA which in turn will likely reduce progression to cirrhosis, liver failure and hepatocellular carcinoma. The key endpoints in determining the efficacy of therapy include suppression of serum HBV DNA to low and preferably undetectable levels, normalisation of ALT levels, histologic improvements, HBeAg seroconversion in HBeAg-positive patients, and the relatively rare event of HBsAg seroconversion.

In individuals acutely exposed to known contaminated blood, hyperimmune globulin can limit the risk of acute infection.

The information provided below is derived from US treatment algorithms, AASLD*, EASL**, and APASL*** Guidelines, according to which, the currently preferred first-line monotherapy treatment options include the use of Adefovir, Entecavir and Pegylated Interferon, which has almost completely replaced standard interferon alfa-2b.

Prevention of vertical transmission: Transmission of hepatitis B from mother to infant occurs during the perinatal period. The risk of infection is 26-40% if the mother is HBeAg positive. Mothers with acute hepatitis B during pregnancy transmit the virus in up to 70% of pregnancies if infection occurs in the third trimester, and up to 90% if it occurs within 8 days of delivery.

Lamivudine and Telbivudine are not preferred first-line drugs in most populations, because of high resistance rates.

Measures to prevent vertical transmission include administration of hepatitis B vaccine and hepatitis B immuno-globulin (HBIG) to neonates within 12 hours of delivery by a carrier. This results in >90% reduction of the risk of transmission.

Recent trends include treatment of patients with any elevation of HBV-DNA with compensated or decompensated cirrhosis. Combination therapy with nucleos(t)ide analogues is also now widely used in cirrhotic patients as well as in patients with HBV and HIV co-infection or in patients who have undergone BMT after HBV infection.

Unlike hepatitis C, hepatitis B is highly infectious through the sexual route and close personal contact. Detailed advice and immunisation need to be given to the patientâ&#x20AC;&#x2122;s immediate family and sexual partner(s).

* AASL: American Association for the study of Liver Disease ** EASL: European Association for the study of Liver Disease *** APASL: Asian Pacific Association for the study of Liver Disease

101

ñ The rates of genotypic resistance with long-term therapy are high with lamivudine (70% at 4-5 years), somewhat less with telbivudine (21.6% in HBe-Agpositive and 8.6% in HBeAg-negative patients at year 2), intermediate with adefovir (30% at 5 years of therapy in HBe-Ag-negative patients), and low with entecavir in nucleoside-naïve patients (<1% at year 4), but higher in lamivudineresistant patients (~42% at year 4). Oral drugs with a high genetic barrier to resistance and/or high potency are generally preferred to reduce the likelihood of resistance. Interferon and peginterferon therapy have not been associated with the development of resistance

Summary: Implications for Clinical Practice The key recommendations based on updated treatment guidelines for treatment of chronic Hepatitis B are as follows: ñ Patients with HBeAg-positive chronic Hepatitis B should receive treatment when serum HBV DNA levels are ≥ 20,000 IU/mL and ALT levels are elevated, particularly 2-fold ñ Patients with HBeAg-negative chronic Hepatitis B should receive treatment when serum HBV DNA levels are ≥2,000 IU/mL and ALT levels are elevated ñ Genotype testing should be used more broadly. Knowledge of genotype may be useful in predicting natural history. For example, genotype C HBV is associated with more advanced disease and a higher rate of HCC than genotype B in Asians. For patients considering pegylated interferon therapy, genotype is useful in predicting response to therapy: HBV genotype A responds much better than genotype D (common genotypes in whites), and genotype B responds somewhat better than genotype C (common genotypes in Asia)

ñ Potential future therapies for chronic Hepatitis B include pegylated interferon and other nucleos(t)ide analogues, particularly tenofovir that is in late-stage studies and shows promise of high potency and low rates of resistance. The role of combination therapy is evolving, primarily to reduce the rate of resistance with long-term therapy

ñ All patients with chronic hepatitis B and cirrhosis with HBV DNA levels ≥ 2,000 IU/mL should be treated. In addition, it may be appropriate to treat all patients with cirrhosis and viraemia regardless of HBV DNA levels, particularly if ALT levels are elevated. Preliminary evidence also supports the use of combination nucleos(t)ide agents in these patients, and therapy should probably used be long-term, even after HBeAg seroconversion in HBeAg-positive patients

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Examples of treatment algorithms for specific groups with HBV infection include:

US Treatment Algorithm Recommendations for Treatment of HBeAg-Positive or HBeAg-Negative Cirrhotic Patients ñ HBV DNA < 2,000 IU/mL and compensated cirrhosis - May choose to treat or observe - Adefovir or entecavir preferred; pegylated interferon alfa-2a may be option in early well-compensated cirrhosis ñ HBV DNA ≥ 2,000 IU/mL and compensated cirrhosis - Treat; adefovir or entecavir are first-line options - Long-term treatment required, and combination therapy may be preferred (adefovir or tenofovir plus lamividine, telbivudine or entecavir) ñ HBV DNA < 200 IU/mL or ≥ 200 IU/mL and decompensated cirrhosis - Combination therapy preferred (adefovir or tenofovir plus lamivudine, telbivudine or entecavir) - Long-term treatment required - Wait-list for liver transplantation Reference: Hepatitis Annual Update 2007 website:http://clinicaloptions.com/Hepatitis/AnnualUpdates

2007 AASLD Guidelines on Management of Chronic Hepatitis B Patients with Compensated Cirrhosis ñ Who to treat - Patients who are HBeAg positive or negative - Patients with HBV DNA > 2,000 IU/mL; no ALT specified - Consider treating if ALT elevated for patients with HBV DNA < 2,000 IU/mL - Observe for patients who are HBV DNA negative ñ Drugs of Choice - Adefovir or entecavir preferred Reference: Hepatitis Annual Update 2007 website:http://clinicaloptions.com/Hepatitis/AnnualUpdates

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2007 AASLD Guidelines on Management of Chronic Hepatitis B Patients with Decompensated Cirrhosis 単 Who to treat - HBeAg positive or negative at any HBV DNA level 単 Drugs of choice - Combination of lamivudine or telbivudine plus adefovir or entecavir monotherapy is preferred (interferons contraindicated) 単 Duration of therapy - Long-term 単 Other recommendations - Refer for transpalntation Reference: Hepatitis Annual Update 2007 website:http://clinicaloptions.com/Hepatitis/AnnualUpdates

Potential Management of Hepatitis B Antiviral Drug Resistance Resistance Type

Strategy

Lamivudine

Continue lamivudine and add adefovir (preferred over switch to adefovir) or tenofovir Switch to emtricitabine/ tenofovir*

Adefovir

Continue adefovir and add lamivudine or telbivudine (preferred over switch to lamivudine or telbivudine) Switch to or add entecavir (if no prior lamivudine resistance) Switch to emtricitabine/tenofovir*

Entecavir

Switch to or add adefovir or tenofovir*

Telbivudine

Continue telbivudine and add adefovir or tenofovir* Switch to emtricitabine/tenofovir*

* Not approved by the FDA for the treatment of Hepatitis B Reference: Hepatitis Annual Update 2007 website:http://clinicaloptions.com/Hepatitis/AnnualUpdates

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Advantages and Disadvantages of Current Therapies for Chronic Hepatitis B Agent

Advantages

Disadvantages

Interferon alfa-2b

ñ HBsAg loss rates ñ Short treatment duration ñ No drug resistance

ñ Parenteral administration ñ Frequent adverse effects

Lamivudine

ñ ñ ñ ñ

ñDrug resistance common (~20%/yr and up to 70% with 4-5 yrs of therapy)

Adefovir

ñ Oral administration ñ Excellent tolerance ñ Use in ESLD* ñ Use in lamivudine failures

ñ 24-to 48-week HBV response less potent than entecavir and telbivudine ñ Drug resistance delayed and less common than with lamivudine, but more common than with entecavir with extended therapy (0% at Yr 1, 3% at Yr 2, 11% at Yr 3, 19% at Yr 4, and 30% at Yr 5 of therapy in HBeAgnegative patients)

Entecavir

ñ Oral administration ñ Excellent tolerance ñ High potency in lowering HBV DNA levels ñ Use in adefovir failures

ñ Drug resistance: rare in nucleosidenaïve parents (estimated at < 1% at Yr 4), but common in patients with lamivudine resistance (estimated at 6% at Yr 1, 14% at Yr 2, 33% at Yr 3, and 42% at Yr 4)

Pegylated Interferon

ñ HBsAg loss ñ Fixed duration of treatment ñ No drug resistance

ñ Parenteral administration ñ Frequent adverse effects but less than recombinat standard interferon

Telbivudine

ñ Oral administration ñ Excellent tolerance ñ High potency in lowering HBV DNA levels

ñ Drug resistance: intermediate rates of drug resistance in treatment-naïve patients (5.0% at Yr 1, and 21.6% at Yr 2 in HBeAg-positive patients, and 8.6% at Yr 2 in HBeAg-negative patients)

Oral administration Excellent tolerance Use in ESLD* Use in adefovir failures

* ESLD, end-stage liver disease Reference: Hepatitis Annual Update 2007-Emmet B. Keeffe,

website:http://clinicaloptions.com/Hepatitis/AnnualUpdates

treatment of CHC/B, should be decided in consultation with and monitored by a specialist hepatologist.

The authors of this book have made an effort to provide readers with essential information on CHC and CHB treatment. However,

105

Infections in Thalassaemia Major

briefest interaction with patients with thalassaemia, should have the same awareness, as should patients themselves. A basic outline of the effects of infection in thalassaemia and their practical implications are provided in Table 1 (see also Table 2 for more blood-borne infections).

Infections are the second commonest cause of death in thalassaemia major. Clinicians involved in the care of thalassaemia will be fully aware of this risk and the importance of any intervention that may limit it (Rahav, Volach et al, 2006). However, all medical and nursing staff, including those with the Blood borne transmission

Relevance for severity

Anaemia Splenectomy

Parvovirus B19 HIV

Orientation for practical management

Iron Iron overload chelation

Vaccine Sensitive to broad Suspend available spectrum chelation antibiotics if suspected

+++

Note

Pregnancy

HBV

+++

Yes

HCV

+++

CMV

+++

Yes

Meningococcus

+++

Yes

Hemophilus

+++

Yes

Klebsiella

Yes

Pseudomonas

Yes

Vibrio vulnificus

Yes

Escherichia coli

Yes

Salmonella

Yes

Yersinia

+++

Yes

deferrioxamine

Yes

Deferrioxamine-

Stem cell transplant

Streptococcus pneumoniae

Influenzae

enterocolitica Mucor species

Immunosuppression Pythium

+++

Yes

Yes?

Farming

insidiosum

Table 1: A summary of the effects of infection in thalassaemia and their practical implications.

106

The pathogens most commonly associated with post-splenectomy sepsis are encapsulated organisms, particularly:

A patient with thalassaemia major must not be considered as immuno-compromised per se, particularly if the disease is well compensated by treatment. On the other hand, many alterations to the body’s immune system have been described in thalassaemia, including reduction in neutrophil numbers, changes in number and function of natural killer cells, increase in number and function of CD8 suppress cells, occurrence of macrophages, chemotaxis and phagocytosis and interferon gamma production.

ñ Streptococcus pneumoniae (accounting for more than 75% of documented bacterial infections in asplenic patients); ñ Haemophilus influenzae, and; ñ Neisseria meningitides. Infections with gram-negative, rod-shaped bacteria, notably Escherichia coli, Klebsiella species (e.g., pneumoniae) and Pseudomonas aeroginosa, occur with increased frequency in asplenic patients and are often associated with high mortality. Other gram-negative organisms have also been implicated in postsplenectomy sepsis.

Even in the absence of any evidence-based data on a direct relationship between these alterations and the development of severe infections in thalassaemia, it is recognised by treating physicians through clinical observations and practice that several factors linked to the disease, its complications and treatment may facilitate or aggravate the severity of infections.

Protozoan infections due to Babesia have been implicated in a fulminant haemolytic febrile state in splenectomised patients, and Malaria is repeatedly reported as more severe in asplenic people with an increased risk of death (Boone and Watters, 1995) (for blood-borne infections see Table 2).

Where infection is suspected, the main causes to be considered include: ñ Splenectomy; ñ Transmission of pathogens by blood transfusion; ñ Iron overload and ñ Iron chelation.

Iron overload The role of iron load in susceptibility to infection has not yet been fully established in clinical trials. It is clear, however, that a variety of microorganisms are more pathogenic in the presence of iron overload.

Splenectomy The major long-term risk after splenectomy is overwhelming sepsis. In older studies, the risk of postsplenectomy sepsis in thalassaemia major is increased more than 30-fold in comparison with the normal population (Singer, 1973). Modern preventative measures (see below) have reduced this risk but the overall impact of these measures is unclear.

The best-described association between bacterial infection, iron and iron chelators involves Yersinia enterocolitica (see below).

107

manifestations: erythema infectiosum or fifth disease in children, mild to severe aplastic crises and myocarditis. During pregnancy severe foetal anaemia and myocarditis may lead to lethal non-immune hydrops fetalis.

Many other organisms, such as Klebsiella species, Escherichia coli, Streptococcus pneumonia, Pseudomonas aeroginosa, Legionella pneumophila and Listeria monocytogenes, have been shown to have increased virulence in the presence of excess iron. On the other hand, phagocytic efficiency, tested in vitro, is impaired in patients with thalassaemia with iron overload compared with individuals without thalassaemia.

In patients with an already shortened red cell lifespan (15-20 days) combined with anaemia due to haematological disorders such as spherocytosis, sickle-cell anaemia, autoimmune haemolytic anaemia and thalassaemia, B-19 infection may cause an acute, life-threatening red cell aplasia, commonly referred to as “transient aplastic crisis”. The cessation of erythropoiesis lasts for 5-7 days and haematologically complicates chronic haemolytic anaemia. The condition is characterised by:

Several observations in vivo indicate that infections are more frequent or severe in patients with iron overload either related to genetic haemochromatosis or to transfusions, as in thalassaemia. The role of iron overload in aggrevating Mucormycosis in bone marrow transplanted patients has been demonstrated.

ñ A variable fall in haemoglobin; ñ Disappearance of reticulocytes from peripheral blood (< 0.2%); ñ A virtual absence of red blood cell precursors in the bone marrow at the beginning of the crisis and ñ B-19 DNA viraemia.

Iron chelators A potential risk of natural siderophores, as in deferoxamine, is that they may be used by micro-organisms as a source of iron, and so become more virulent. This has been demonstrated in vitro and in vivo for Yersinia enterocolitica, which has a receptor on the outer membrane that efficiently binds ferrioxamine.

Following recovery from an acute B-19 infection, patients are typically immune to further infections by the agent. Where patients are immunosuppressed (e.g. transplanted, HIV-infected) and fail to mount an effective antibody response to the virus, the infection may be persistent and may mimic or trigger autoimmune inflammatory disorders.

A clear relationship between Mucormycosis and desferrioxamine has been reported in dialysis patients but only sporadically in thalassaemia. Similar observations have been reported for Rhizopus infections. Specific infections

B-19 may be transmitted via the respiratory system or blood derivates. The incidence of B-19-infected individuals with persistently detectable levels of B-19 DNA, despite the presence of specific IgG, is estimated at 1% of blood donors. The resulting risk of

Viral Infections Human Parvovirus B-19 (HPV B19) Parvovirus B-19 is a common pathogen that may cause a wide range of clinical

108

policies addressing the problem, as well as on the local prevalence of blood transmissible pathogens.

infection is estimated at between 1/625 and 1/50,000, depending on a number of factors (including detection methods, seasonal outbreaks, B-19 DNA load of the donor and co-presence of B-19 IgG antibodies) (Lefrere, Maniez-Montreuil et al, 2006). There is currently no general rule on action to be taken to prevent blood-borne transmission of B-19 in high-risk populations, including thalassaemia major patients.

With the use of standard procedures for prevention, it is possible to keep the risk of HIV transmission very low; with the use of the most sensitive screening measures, it is possible to lower this risk still further.

Management of acute B-19 crises includes close monitoring and adequate blood transfusion adjustment. Immunoglobulin administration may be beneficial in chronic illness.

Natural history In the absence of treatment, the median time from HIV seroconversion to the onset of AIDS in transfused patients is about 7-11 years. Factors affecting progression are symptomatic primary infection, age at infection and viral load (HIV1-RNA concentration in plasma).

Human Immunodeficiency Virus (HIV)

Management of HIV in thalassaemia A detailed account of the treatment and monitoring of HIV patients is beyond the scope of this book. Patients with thalassaemia identified with HIV infection should be managed in collaboration with an infectious diseasesâ&#x20AC;&#x2122; unit with expertise in HIV. Advances in drug treatment have revolutionised the care of patients from strategies aimed at preparing patients to die to treatments that may fully control the disease. However, accessing the bestâ&#x20AC;&#x201D;and most expensiveâ&#x20AC;&#x201D;treatment will depend on local conditions.

Risk of transfusion-associated infection Although sensitive and specific laboratory serologic tests became available soon after the discovery and description of HIV, a number of patients with thalassaemia who received transfusions previous to HIV screening have been infected. Many more are still being infected in countries where effective protective measures for blood safety, including blood donor selection and testing, have yet to be applied.

The prevalence of HIV infection in thalassaemia varies greatly worldwide, from <1% to >20%. In Italy,

Special considerations in thalassaemia Although antiretroviral therapy should be administered to patients with thalassaemia major based on the same general guidelines used for other infected non-thalassaemic individuals, side effects such as endocrine dysfunction and diabetes could be more significant.

for example, the prevalence is currently 1.7% while in Cyprus it is 0.17%. The rate of HIV infection as with other infections among transfused patients depends on the timing of introduction and quality of public health

109

Viruses enveloped

non-enveloped

HIV-1, HIV-2, HTLV-I, HTLV-II CMV, HHV-6, HHV-8, EBV HBV, HCV, HGV HAV; parvo B19, TTV

Bacteria Gram-positive

Gram-negative

Staphylococcus epidermidis Staphulococcus aureus Coagulase negative stachylococci Streptococcus viridans Enterococcal species Bacillus cereus Yersinia enterocolitica Pseudomonas fluorescens Salmonella enteritidis Citrobacter freundii Serratia marcescens Enterobacter cloacae Coliform bacteria Flavobacterium species

Protozoa Plasmodium Plasmodium Plasmodium Plasmodium

vivax falciparum malarias ovale

Trypanosoma cruci Babesia microti Toxoplasma gondii Leishmania donovani

Others Treponema pallidum Prions Abbreviations in Table 2: HIV: human immunodeficiency virus, HTLV: human T-cell leykaemia/lymphoma virus; CMV: cytomegalovirus, HHV: human herpes virus; EBV: Epstein-Barr virus; HBV: hepatitis B virus; HCV: hepatitis A virus; parvo B 19: parvovirus B19;TTV: transfusion-transmitted virus. Ref. A. Modell, ZLB Central Laboratory Swiss Red Cross, Bern, Switzerland 2000.

Table 2: Transfusion transmitted pathogens

110

organ transplant recipients, CMV infection constitutes a major, if not one of the most important causes of morbidity and mortality.

There is general agreement that a patientâ&#x20AC;&#x2122;s iron status influences the outcome of HIV-1 infection. In HIV-infected patients with thalassaemia major, the rate of progression of HIV was significantly faster in patients with low level of chelation with deferoxamine and higher serum ferritin concentrations. Further to the capacity to remove iron, iron chelators, mainly deferiprone, show interesting antiviral properties in vitro, but there is so far no evidence of a direct antiviral effect. Optimal control of iron overload with iron chelation is therefore recommended in HIV-positive patients with thalassaemia and the choice of chelator should take into consideration the above data as well as the individualâ&#x20AC;&#x2122;s needs. Because of an increased risk of neutropenia, deferiprone should be used with caution in such cases.

Unlike the case with other infectious agents, the presence of serum CMV IgG antibodies does not preclude infectiousness. It is estimated that approximately 2-12% of antiCMV positive healthy donors are infectious, i.e. can transmit the virus. The increasing use of bone marrow transplantation as a treatment for thalassaemia demands special attention to the serological status of CMV. Prevention of transmission through blood products is effectively achieved by the use of anti-CMV negative donation, but this policy may be applied only in special conditions, such as stem cell transplantation, because exclusion of CMV positive donors (50-75% of the adult population are anti-HCMV positive) will affect significantly the national pool of blood supply. As CMV is WBC-associated virus, the widespread use of leucocyte filtration, in recent years recommended for all patients with thalassaemia, no matter what their condition, constitutes an effective preventative measure.

While there is no direct evidence that splenectomy facilitates the progression of HIV infection, a decision to perform splenectomy in an HIV-positive patient with thalassaemia should be made with extreme caution. Of particular concern is the removal of an important fraction of T cells and the potential for overwhelming infection in immuno-compromised patients.

Bacterial infections

Human Cytomegalovirus (HCMV)

Yersinia enterocolitica Mechanisms of infection The Yersinia organism is most commonly transmitted by the ingestion of contaminated food, meat, milk or water, although it is commensal in healthy individuals. On rare occasions it becomes virulent, crossing the intestinal membrane and provoking life-threatening infections. The best known factor predisposing the organism

Transfusion-associated CMV has a wide clinical spectrum. In the immuno-competent patient-host, it is usually sub-clinical or may appear as an infectious mononucleosis-like syndrome. In the immuno-compromised host, however, such as bone marrow or

111

Post-infection sequelae include erythema nodosum and reactive arthritis, mostly in adults.

to virulence is the availability of a large amount of iron, as is the case in severe iron overloaded patients or in those undergoing iron chelation with desferrioxamine (Vento, Cainelli and Cesario, 2006), as described above.

Laboratory diagnosis Specific culture conditions (at 22oC for 48 hours) are necessary to identify Yersinia species and in this context, the treating physician should inform the laboratory of his/her suspicions in order to enable it to proceed to the correct culture conditions for blood and stool samples.

Transfusion-associated transmission of Yersinia enterocolitica may occur from apparently healthy donors, albeit rarely, as the organism can survive and multiply under normal storage conditions (4oC). The mortality rate among recipients of contaminated blood is >50%.

Serologic tests for Yersinia are problematic because of the likelihood of cross-reactivity. However, a four-fold rise in IgG titres in serial samples obtained 15 days apart may be suggestive of recent infection. Overall, the pickup rate for stool, blood culture and seroconversion is low. In some cases diagnosis may only be made after obtaining samples of affected tissue (e.g. gut, lymph node).

Clinical manifestations The clinical manifestations of Yersinia infection depend on the age and health of the host. While variable, these manifestations are severe in over 80% of cases involving patients with thalassaemia. Fever is the most common presenting feature, often associated with abdominal pain and diarrhoea or vomiting. Extra gastrointestinal manifestations, such as acute respiratory distress syndrome, arthralgia and skin rashes, are also sometimes seen.

Treatment The basic but most important point is that anyone involved in the care of a patient with thalassaemia with the above-described symptoms must be aware of the risk of Yersinia infection and its management. Simple information leaflets issued by the treating centre and carried by the patient or parents of children may be of help, especially when travelling.

The most typical clinical picture is an â&#x20AC;&#x2DC;acute abdomenâ&#x20AC;&#x2122; that mimics and may even be indistinguishable from acute appendicitis/peritonitis, caused by mesenteric lymphadenitis. It is important to have this critical point in mind, as the two conditions require a very different antimicrobial approach.

In the absence of a quick reliable laboratory diagnosis, treatment must begin on the basis of clinical suspicion. In such cases, the following measures should be taken:

The most dangerous condition is septicaemia, which, in the absence of specific antibiotics, may be fatal in more than 50% of cases. Complications may include abdominal, hepatic or splenic abscess, intussusception, nephritis, ileo-psoas abscess and meningitis.

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infection by Campylobacter and Chryseobacterium meningosepticum. Despite the in vitro data for micro-organisms such as Listeria monocytogenes and Salmonella, there is no in vivo evidence that the prevalence and severity of related infections in thalassaemia is higher than in the nonthalassaemic population.

単 Stop iron chelation therapy immediately 単 Obtain suitable laboratory samples 単 Commence antibiotic treatment immediately Yersinia species are typically intracellular and therefore antibiotics with good intracellular penetration are recommended. In mild suspected cases, oral ciprofloxacin is the recommended first line treatment. In severely unwell patients, immediate parenteral therapy is mandatory with the same drug. I.v. trimethoprimsulfomethoxazole or cephalosporins may be added or used as an alternative.

Klebsiella species Klebsiella infections in thalassaemia major and even more in HbE/b-thal are associated with high mortality and morbidity rates are occasionally reported in the literature. In a large retrospective study including 160 patients, the prevalence was reported to be 7.5%, with a clinical spectrum including sinusitis, intracranial infection, meningitis, septicaemia and pyogenic abscesses of the liver, lung and kidney. Mortality rate was 16%, and permanent neurological sequelae 25%. Predisposing factors seemed to be iron overload and liver function derangement (Chung et al, 2003).

It is generally advisable to continue antibiotics for at least two weeks after proven infection. Iron chelation should not be restarted until the patient has been asymptomatic for over a week. Some patients relapse after restarting desferrioxamine. Whenever possible, an alternative chelator should be prescribed. In contrast to deferoxamine, the synthetic chelators, deferiprone and deferasirox do not seem to trigger Yersinia enterocolitica virulence.

Pseudomonas aeruginosa in thalassaemia constitutes the most common pathogen-related infection to the central venous catheter. It may cause severe infections such as meningitis (Wang, Lin et al, 2003). Splenectomy seems to be the main predisposing factor.

Other bacterial infections

Melioidosis of the musculoskeletal system caused by Pseudomonas pseudomallei has been sporadically reported in thalassaemia.

Other micro-organisms that may cause severe infections and should be seriously considered in the management of unwell patients with thalassaemia include Klebsiella species, Pseudomonas species, Vibrio vulnificus, Escherichia coli, Salmonella species and Mucor species. Recent papers also report

Vibrio vulnificus is sporadically reported as the cause of severe infections, including septicaemia, wound infections and meningitis in patients with thalassaemia in South-East Asia. Iron overload is likely to be the most important predisposing factor.

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have been observed in patients with thalassaemia (Krajaejun et al, 2006).

Escherichia coli is not reported as a significant pathogen in thalassaemia major, being clinically significant in patients with HbE/â&#x20AC;&#x161;-thalassaemia, as for Klebsiella.

The disease has high rates of morbidity and mortality and early diagnosis and prompt initiation of effective treatment are extremely important. The organism does not respond to antifungal agents. A vaccine has been recently developed which has demonstrated at this preliminary stage effectiveness in patients with thalassaemia. (Krajaejun et al, 2006)

Salmonella species Many in vitro data suggest that patients with thalassaemia, particularly those that are splenectomised, have a decreased opsonic activity and phagocytic efficiency against Salmonella species. Overall, however, in vivo the prevalence of Salmonella infections does not seem higher than in normal subjects.

Common infections not related to thalassaemia

Haemophilus influenzae Thalassaemics appear to have a lower natural immunity to this microorganism, however vaccine-induced immunity seems to be effective.

Dengue Haemorragic fever due to dengue viral infection is endemic in Southeast Asian countries where thalassaemias are also common. In an uncontrolled study from Thailand, dengue was reported to be frequent and more severe than expected in patients with thalassaemia, underscoring the need for providing special awareness of proper diagnosis and management, particularly in these regions of the world.

Fungi Mucor species Mucormycosis or Zygomycoses are opportunistic fungal infections caused by ubiquitous organisms of the Zygomycetes class. The relationship with conditions of iron overload and deferoxamine use is well known.

Helicobacter pylori

In thalassaemia, severe infections have been observed only in immunocompromised subjects after stem cell transplantation.

In one study of patients with thalassaemia with recurrent abdominal pain, the prevalence of H. pylori infection was not statistically different from matched nonthalassaemic healthy subjects.

Pythiosum insidiosum Pythiosis is caused by the oomycete Pythium insidiosum. Human pythiosis has been reported in Thailand among farmers and their relatives although zoonosis is prevalent in many other parts of the world. The most severe forms (cutaneous, vascular and disseminated pythiosis)

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Malaria and thalassaemia

∆ransfusion-related Malaria and Chaga’s disease

There is evidence that in most cases, being a healthy carrier of a haemoglobinopathy provides protection against the clinical severity of malaria. However, the same is not true for the homozygous state. Patients with

Post-transfusion malaria and Chaga’s disease have been known for more than 50 years. Plasmodium species and Trypanosoma cruzii may remain viable for at least two weeks in refrigerated blood components as well as in frozen plasma, and in this context, there are great concerns that increased tourism to and from endemic countries might increase the frequency of transfusion-transmission of these pathogens. Both infections remain an important topic for blood transfusion services, and national standards including donor selection have been drawn up based on WHO, Council of Europe, EU and North American Authorities’ recommendations, in order to prevent or minimise the transmission of these diseases.

‚-

thalassaemia major or intermedia are not protected from severe malaria and may indeed be more prone to severe forms of the disease, depending on their clinical condition (anaemia, splenomegaly, iron overload and other complications). Patients must therefore be provided with specific advice for the prevention of malaria before and during periods of travel in endemic areas.

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Splenectomy in ‚-thalassaemia

splenomegaly causes concern about possible splenic rupture.

Many patients with thalassaemia major require splenectomy. However, optimal clinical management from the time of diagnosis may delay or even prevent hypersplenism, thereby increasing the efficiency of transfusion therapy and reducing the need for splenectomy. Throughout the care of the patient with thalassaemia, the size of the spleen should be carefully monitored on physical examination and, as needed, by ultrasonography.

ñ Leucopenia or thrombocytopenia due to hypersplenism causes clinical problems (e.g. recurrent bacterial infection or bleeding). Splenomegaly due to periods of undertransfusion with blood of inappropriately low haemoglobin may be reversible. Before considering splenectomy in this situation, the patient should be placed on an adequate transfusion programme for several months and then re-evaluated.

Splenectomy should be considered when: ñ Annual blood requirements exceed 1.5 times those of splenectomised patients, provided that they are on the same transfusion scheme and have no other reasons for increased consumption. Such reasons include new alloantibodies, infection, and changes in the haematocrit of the transfused units. For patients maintaining a pre-transfusion Hb level of about 10 g/dl, this increase in transfusion requirements represents consumption of more than 200-220 ml of red cells (assuming haematocrit of transfused cells is 75%)/kg/year (Modell, 1977; Cohen, 1980). The rate of iron overload should also be taken into consideration. For patients who maintain effective chelation therapy despite increased blood requirements, splenectomy may be unnecessary. For patients with increasing iron stores despite good chelation therapy, reduction in the rate of transfusional iron loading by splenectomy may be an important component of the overall management of iron overload.

It is generally advisable to delay splenectomy until patients are at least five years old because of the increased risk of overwhelming sepsis below this age (see below).

Surgery The two surgical techniques most commonly employed for total splenectomy are the open and laparoscopic approaches. The laparoscopic approach requires a longer operative time and may not be practical for patients with very large spleens, but the recovery period is shorter and there is virtually no surgical scar. Many surgeons now have extensive experience with this approach. In some centres, partial splenectomy is used to preserve some of the immune function of the spleen while reducing the degree of hypersplenism (De Montalembert, 1990). The long-term success of this approach is still undergoing evaluation. In particular, the

ñ Splenic enlargement is accompanied by symptoms such as left upper quadrant pain or early satiety. Massive

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likelihood of splenic re-growth and the volume of splenic tissue required to preserve immune function are two questions outstanding. Any surgery on the spleen should include a careful search for accessory spleens.

thrombotic tendency, special consideration should be given to the use of low-dose aspirin (80 mg/kg/d) for patients with high platelet counts, or the use of anticoagulation for patients with a history of previous thrombosis or other risk factors.

Reduction of splenic tissue by embolisation is a less invasive approach to hypersplenism than complete or partial surgical splenectomy (Pringle, 1982). However, this approach has not gained wide acceptance and may be complicated by fever, significant pain and the possible need for a subsequent total splenectomy. Embolisation does not permit a search for accessory spleens.

The major long-term risk after splenectomy is overwhelming sepsis. In older studies, the risk of postsplenectomy sepsis in thalassaemia major is increased more than 30-fold in comparison with the normal population (Singer, 1973). Modern preventative measures (see below) have reduced this risk but the overall impact of these measures is unclear. The pathogens most commonly associated with postsplenectomy sepsis are encapsulated organisms (Pedersen, 1983), particularly:

An evaluation for gallstones should be performed prior to surgery, especially if the patient has experienced symptoms suggestive of biliary tract disease. In some cases, positive findings will lead to cholecystectomy at the same time as splenectomy. Removal of the appendix at the time of splenectomy may prevent later problems in distinguishing infection with Yersinia enterocolitica from appendicitis. Splenectomy also provides a good opportunity for a liver biopsy to assess the liver histology and iron concentration.

単 Streptococcus pneumoniae (accounting for more than 75% of documented bacterial infections in asplenic patients) 単 Haemophilus influenzae 単 Neisseria meningitidis Infections with gram negative, rod-shaped bacteria, notably Escherichia coli, Klebsiella and Pseudomonas aeroginosa, occur with increased frequency in asplenic patients and are often associated with high mortality. Other gram-negative organisms have also been implicated in postsplenectomy sepsis.

Appropriate immunisations should be administered at least 2 weeks before splenectomy (see below).

Protozoan infections due to Babesia have been implicated in a fulminant haemolytic febrile state in splenectomised patients. Malaria is reportedly more severe in asplenic people (Boone, 1995) and carries an increased risk of death.

Complications of splenectomy Peri-operative complications include bleeding, atalectasis and subphrenic abscess. Postoperative thrombocytosis is common, with platelet counts often reaching 1,000,000-2,000,000/mm3. Because patients with thalassaemia may have an increased

Characteristics of overwhelming postsplenectomy sepsis include the sudden onset of fever and chills, vomiting and headache.

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(Landgren, Bjorkholm et al, 2004). The currently available pneumococcal vaccine is a 23-valent polysaccharide vaccine that can be given subcutaneously or intramuscularly. A conjugate vaccine will be available shortly. The protection rate with the 23-valent vaccine is 70-85%. Pneumococcal vaccine should be given at least 2 weeks in advance of a splenectomy and then in 3-5 years. The immune response to this polysaccharide vaccine is poor in children less than two years of age. Children vaccinated under the age of two should be re-vaccinated at age two. Patients who underwent splenectomy without being given pneumococcal vaccine may still benefit from vaccination postsplenectony.

The illness rapidly progresses to hypotensive shock, and is commonly accompanied by disseminated intravascular coagulation. Postsplenectomy sepsis has many of the features of adrenal haemorrhage (Waterhouse-Friederichsen syndrome). The mortality rate for such infections is approximately 50%, despite intensive supportive measures. Therefore, early intervention on the basis of clinical suspicion, even in the absence of many of the above findings, is critical. The risk of overwhelming postsplenectomy infection varies with: ñ Age—risk is very high in children <2 years of age. However, fulminant bacteraemia has been reported in adults as much as 25-40 years after splenectomy. ñ Time since splenectomy—the greatest risk appears to be in the period 1-4 years after surgery ñ Immune status of patient

If not administered as part of routine childhood immunisations, Haemophilus influenzae vaccine should be given to patients before they undergo splenectomy and should also be given to splenectomised patients (Spoulou, Tsoumas et al, 2006). Meningococcal polysaccharide vaccine should also be administered to patients who are undergoing splenectomy and to nonimmunised, previously splenectomised patients.

Preventative measures The three types of protective measures a physician can utilise to prevent postsplenectomy sepsis include:

These vaccines can be given at the same time in different syringes at different sites. Yearly administration of influenza virus vaccine is recommended to prevent this febrile illness that might otherwise require intensive evaluation and management of a febrile episode in the splenectomised host with thalassaemia (see below).

1. Immunoprophylaxis 2. Chemoprophylaxis 3. Patient education

Immunoprophylaxis Vaccination against Streptococcus pneumoniae is a critical step in preventing overwhelming infection after splenectomy

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febrile illnesses and seeking immediate medical attention. For all febrile episodes, the physician should strongly consider:

Chemoprophylaxis Chemoprophylaxis with oral penicillin, 125 mg b.i.d. for children under two years, and 250 mg b.i.d. for children two years and over is recommended to reduce the risk of postsplenectomy sepsis. Alternative antibiotics for patients unable to take penicillin include amoxicillin, trimethoprim-sulfomethoxazole and erythromycin. All splenectomised children under five years of age should be treated with prophylactic antibiotics. The value of chemoprophylaxis after this age is unproven. Some clinicians continuously treat all splenectomised patients with prophylactic antibiotics, irrespective of age, while others treat patients whose spleens are removed after the age of five years only for the first two years after splenectomy. The use of prophylactic antibiotics will need to be regularly re-evaluated as improved vaccines become available and as new data regarding antibiotic-resistant bacteria are developed.

Evaluating the patient, including a complete physical examination Obtaining blood and other cultures as indicated. Beginning treatment with an antimicrobial regimen effective against Streptococcus pneumoniae and Neisseria meningitidis. If bacteraemia is suspected, the patient should be treated with parenteral antibiotics and observed in a medical facility until the cultures are evaluated. Patients also need to be made aware of the potential for travel-related infections such as babesiosis and malaria, as well as the risk inherent in travel to an area where medical care is not readily accessible. In the latter case, an appropriate antibiotic should be made available for the patient to carry with him/her.

The importance of compliance with prophylactic antibiotics should be stressed repeatedly to patients and parents. However, the limitations of antibiotic prophylaxis must also be emphasised. Patients and parents should recognise that chemoprophylaxis does not prevent all cases of post-splenectomy sepsis: the risk of death from febrile illnesses remains, and rapid evaluation of febrile episode is essential (see below).

Patients should be reminded always to alert consulting physicians about their splenectomised status. Other complications which have been recognized in splenectomised patients include: 単 Thrombophilia 単 Pulmonary hypertension

Education

Thrombophilia- this is a complication which occurs more frequently in thalassaemia intermedia (see relevant chapter), but a higher risk is seen in splenectomised patients. The phenomenon of increased coagulability is related to the fact that damaged red cells

Patient and parent education can be highly effective in preventing overwhelming postsplenectomy infection. Physicians should emphasise to the patient and parents the importance of recognising and reporting

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normally removed by the spleen, persist in the circulation and trigger mechanisms of Thrombin generation (see Figure 2 Chapter 11: Thalassaemia Intermedia and HbE). In postsplenectomy patients markers of thrombin generation such as thrombin AT III (TAT) complexes, prothrombin fragments (F1,2) fibrinopeptide A (FPA) and D-dimer should be assessed annually, and anticoagulant prophylaxis prescribed where indicated.

Pulmonary hypertension â&#x20AC;&#x201C; this complication is more frequent in thalassaemia intermedia, but it is also increasingly identified in thalassaemia major, especially in splenectomised patients.

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Thalassaemia Intermedia and HbE

compound heterozygotes for ‚-thalassaemia, meaning that both ‚-globin loci are affected. The mild clinical characteristics of TI compared with thalassaemia major are primarily the result of the following three mechanisms:

Definition The clinical phenotypes of thalassaemia intermedia (TI) lie between those of thalassaemia minor (heterozygous state) and major (homozygous state), although there is substantial clinical overlap between the three conditions. TI was first described in 1955 by Rietti-Greppi-Micheli, who referred to patients as being ‘too haematologically severe to be called minor, but too mild to be called major’.

ñ inheritance of a mild ‚+ mutation; ñ presence of a polymorphism for the enzyme Xmn-I in the GÁ- promoter region, associated with increased HbF; and ñ co-inheritance of ·-thalassaemia on the ‚-globin locus.

Thalassaemia intermedia encompasses a wide clinical spectrum. Mildly affected patients are completely asymptomatic until adult life, experiencing only mild anaemia and maintaining haemoglobin levels between 710g/dL. These patients require only occasional blood transfusions, if any. Patients with more severe thalassaemia intermedia generally present between the ages of 2 and 6 years, and although they are able to survive without regular transfusion therapy, growth and development can be retarded. The clinical spectrum of thalassaemia intermedia indicates the need for an individualised treatment approach. Despite the availability of a number of treatment options, the lack of clear guidelines can present a significant clinical challenge (Taher, 2006; Camaschella and Cappellini, 1995).

The phenotype of TI may also result from the increased production of ·-globin chains, occurring either by the triplication of · genotype associated with ‚-heterozygosity, or by the interaction of ‚- and ‰‚thalassaemia (Taher, 2006). Analysis of the genotypes of patients with thalassaemia intermedia is important for an early diagnosis of the milder disease, thus avoiding unnecessary blood transfusions. Predicting phenotype from genotype in TI is still difficult, due to the interaction of genetic and environmental factors. Primary genetic modifiers are the numerous genetic alleles at the ‚-chain locus, which can cause either complete or marked reduction in ‚chain synthesis. Secondary genetic modifiers are those that have a direct effect on modifying the amount of excess ·-chains (inheritance of abnormal ·- or Á-chain genes). Tertiary modifiers are polymorphisms occurring at loci involved in bone, iron and bilirubin metabolism that can affect clinical expression. Relevant environmental factors include social conditions, nutrition and the availability of medical care (Taher, Ismaeel and Cappellini, 2006).

Mechanism of TI The pathophysiology of thalassaemias is based on an imbalance of globin-chain synthesis. In the case of ‚-thalassaemia intermedia, the imbalance is greater than that seen in ‚-thalassaemia trait and less than that of ‚-thalassaemia major. Most TI patients are homozygotes or

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accurate identification of these two phenotypes at the onset is remarkably difficult. Nevertheless, a careful analysis of clinical, haematological, genetic and molecular data may allow a reasonable conclusion for treatment (Taher, 2006; Wainscoat, 1987; Weatherall, 2001). (see Table 1 for an outline of the major differences between thalassaemia intermedia and major).

Differential diagnosis Differentiation at presentation between thalassaemia major and thalassaemia intermedia is essential for designing appropriate treatment for an individual patient. The accurate prediction of a mild phenotype may avoid needless transfusions and their complications, while the timely diagnosis of thalassaemia major will allow an early start to a transfusion programme, thus preventing or delaying hypersplenism and reducing the risk of red cell antigen sensitisation. Unfortunately, however, the

Helpful clues in differentiating between thalassaemia major and thalassaemia intermedia Thalassaemia major more likely

Thalassaemia intermedia more likely

Clinical Presentation (years) Hb levels (g/dl) Liver/ spleen enlargement

<2 6-7 Severe

>2 8-10 Moderate to severe

Haematological HbF (%) HbA2(%)

>50 <4

10-50 (may be up to 100%) >4

Both carriers of high HbA2 ‚-thalassaemia

One or both atypical carriers: - High HbF ‚-thalassaemia - Borderline HbA2

Severe No

Mild/silent Yes

Yes

No No

Yes Yes

Genetic Parents

Molecular Type of mutation Coinheritance of ·-thalassaemia. Hereditary persistence of fetal haemoglobin ‰‚ thalassaemia GÁ XMN1 Polymorphism

Table 1

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degree of ineffective erythropoiesis is the primary determinant of the development of anaemia, while peripheral haemolysis of mature red blood cells and an overall reduction in haemoglobin synthesis are secondary determinants.

Pathophysiology of Thalassaemia Intermedia (TI) Three main factors are responsible for the clinical sequelae of thalassaemia intermedia: ineffective erythropoiesis, chronic anaemia and iron overload. The severity of clinical sequelae depends primarily on the underlying molecular defects. a-chains are highly unstable and precipitate into erythroid precursors in the bone marrow, causing membrane damage and cell death (i.e. ineffective erythropoiesis). Hypertrophy of erythroid marrow in medullary and extramedullary sites, a consequence of severe ineffective erythropoiesis, results in characteristic deformities of the skull and face and may also cause cortical thinning and pathological fractures of long bones. The

Complications and management of TI In addition to the defining symptoms of thalassaemia intermedia, which are seen to a lesser or greater extent in other forms of thalassaemia, patients with thalassaemia intermedia experience a number of specific complications that are rare in thalassaemia major. Figure 1 highlights the multitude of complications in untreated thalassaemia (Taher, Ismaeel and Cappellini, 2006; Cappellini, Cerino et al, 2001).

Figure 1: Pathophysiological sequelae of untreated thalassaemia and corresponding clinical manifestations

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Splenomegaly and Splenectomy

Extramedullary haematopoiesis

Splenectomy is now uncommon and is mainly performed late in life. The main indications for splenectomy in thalassaemia intermedia are a significant enlargement of the spleen and a decrease in mean haemoglobin levels in the absence of other transient factors such as infection (Taher, Ismaeel and Cappellini, 2006; Cappellini, Cerino et al, 2001; Borgna-Pignatti, Rigon, Merlo et al, 2003; Galanello, Piras, Barella et al, 2001). As for the type of surgery, the laparoscopic approach is safe and feasible and preferred over open surgery, as a minimally invasive alternative that may become the treatment of choice in â&#x20AC;&#x161;-thalassaemia patients who require concurrent operations. During splenectomy, surgeons should assess the gallbladder for any stones and perform cholecystectomy whenever gallstones are found (Leandros et al, 2006).

Extramedullary haematopoiesis is a compensatory mechanism where bone marrow activity increases in an attempt to overcome the chronic anaemia of thalassaemia intermedia, leading to the formation of erythropoietic tissue masses that primarily affect the spleen, liver, lymph nodes, chest and spine. These masses can be detected by magnetic resonance imaging (MRI). They may cause neurological problems such as spinal cord compression and paraplegia, and intra-thoracic masses. In case of spinal cord compression, clinical awareness is crucial for early diagnosis and prevention of irreversible neurological complications. MRI is the radiological method of choice for diagnosing extramedullary haematopoietic masses and for delineating the extent of spinal cord involvement. Management includes transfusion therapy, as well as radiotherapy and hydroxyurea (Taher, Ismaeel and Cappellini, 2006; Chehal, Aoun, Koussa et al, 2003; Castelli, Graziadei, Karimi and Cappellini, 2004; Saxon, Rees, Olivieri, 1998). Hypertransfusion is a promising treatment method, targeting at higher Hb levels, involving many blood transfusions over a period of weeks to compensate for the demands of erythropoiesis.

Gall stones and cholecystectomy Gallstones are much more common in thalassaemia intermedia than in thalassaemia major as a result of ineffective erythropoiesis and peripheral haemolysis. Similar to laparoscopic splenectomy, laparoscopic cholecystectomy has more favourable and feasible outcome than open cholecystectomy (Taher, Ismaeel and Cappellini, 2006; Cappellini, Cerino et al, 2001; BorgnaPignatti, Rigon, Merlo et al, 2003; Galanello, Piras, Barella et al, 2001; Leandros et al, 2006).

Kidney stones As a result of ineffective erythropoiesis and peripheral haemolysis TI patients are susceptible to kidney stones, which can lead to hydronephrosis and kidney failure. The

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supplementation can help accelerate the healing of ulcers. Hydroxyurea also has some benefit, either alone or in combination with erythropoietin or platelet-derived growth factor. In addition, the use of an oxygen chamber can provide moderate relief since tissue hypoxia may be an underlying cause of the ulceration (Taher, Ismaeel and Cappellini, 2006; Gimmon, Wexler and Rachmilewitz, 1982).

cause is associated with hypertrophic stones that block the renal tubules and even the calyces. The kidneys are frequently enlarged in thalassaemia, due to the presence of extramedullary haematopoiesis.

Leg ulcers Leg ulcers are more common in older rather than younger patients with thalassaemia intermedia. It is unclear why ulcers develop. However, once an ulcer has started to develop it is very painful and difficult to cure, although regular blood transfusions may provide some relief in persistent cases. Zinc

Thrombophilia Patients with thalassaemia intermedia have been shown to have an increased

Figure 2: Thrombotic mechanism in thalassaemia intermedia

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which is thought to be the primary cause of congestive heart failure in this patient population (Aessopos, Farmakis, Karagiorga et al, 2001). The mechanism underlying pulmonary hypertension in thalassaemia intermedia is unclear.

predisposition to thrombosis compared with thalassaemia major patients. Such events mainly occurred in the venous system and comprised deep vein thrombosis (40%), portal vein thrombosis (19%), stroke (9%), pulmonary embolism (12%) and others (20%). Moreover, splenectomised patients have been shown to have a higher risk of thrombosis than non-splenectomised patients (Cappellini, Robbiolo, Bottasso et al, 2000). (See Figure 2 for more on the thrombotic mechanism in thalassaemia intermedia.)

As anaemia and iron overload are uncommon in well-transfused and chelated thalassaemia major patients, the two conditions are likely to be at the root of the pathophysiology of pulmonary hypertension. Regular transfusion and iron chelation therapy is therefore indicated in thalassaemia intermedia patients who are well-stratified according to the early detection of pulmonary hypertension indices. Sildenafil has also been successfully used to treat pulmonary hypertension, although data from large patient numbers are lacking in thalassaemia intermedia (Taher, Ismaeel and Cappellini, 2006; Aessopos, Farmakis, Karagiorga et al, 2001; Aessopos, Farmakis, Deftereos et al, 2005).

Management of thrombophilia has two arms: prevention and treatment. Prevention consists of proper anticoagulation prior to any surgical or other high-risk procedure. Treatment entails the adequate use of anticoagulation according to the recommendations for hypercoagulable states. Awareness is important since thromboembolism plays an important role in pulmonary hypertension and right heart failure (Taher, Ismaeel and Cappellini, 2006; Taher, Ismaeel, Mehio, Bignamini et al, 2006; Eldor, Rachmilewitz, 2002; Cappellini, Robbiolo, Bottasso et al, 2000; Taher, AbouMourad, Abchee et al, 2002).

Hepatitis Hepatitis due to viral (B and C) infection is less frequent in thalassaemia intermedia than in patients with thalassaemia major, since blood transfusions are much less common in thalassaemia intermedia. Abnormal liver enzymes (increased alanine and aspartate aminotransferase) are frequently observed in patients with thalassaemia intermedia, primarily due to hepatocyte damage resulting from iron overload. Normalisation of liver enzyme levels is often observed during appropriate chelation therapy (Taher, Ismaeel and Cappellini, 2006; Cappellini, Cerino, Marelli and Fiorelli, 2001).

Pulmonary hypertension and congestive heart failure Pulmonary hypertension (PHT) is prevalent in patients with thalassaemia intermedia. In a study of 110 thalassaemia intermedia patients (60.9% untransfused or minimally transfused), 59.1% were shown to have PHT,

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However, the mechanism involved in TI is increased absorption from the gut rather than blood transfusions. The resulting iron overload can lead to a number of serious complications, including cardiac failure and endocrine abnormalities such as diabetes mellitus and hypogonadism (Taher, Ismaeel and Cappellini, 2006; Weatherall, 2001).

Endocrine function Hypogonadism, hypothyroidism and diabetes mellitus are quite rare in thalassaemia intermedia. Although patients with thalassaemia intermedia generally experience puberty late, they have normal sexual development and are usually fertile. Hypothyroidism is sometimes observed late in life (Taher, Ismaeel and Cappellini, 2006; Cappellini, Cerino, Marelli and Fiorelli, 2001).

Initiation of iron chelation depends on the amount of excess iron, rate of iron accumulation, and duration of exposure to excess iron. Increased levels of liver iron concentration (LIC) have been observed with small increases in serum ferritin (Fiorelli, Fargion, Piperno et al, 1990). Thus, direct assessment of LIC by biopsy or MRI is recommended. Chelation therapy should be initiated if LIC â&#x2030;Ľ 7 mg/g dry weight of liver (Taher, Ismaeel and Cappellini, 2006).

Pregnancy in TI Women with thalassaemia intermedia may have spontaneous successful pregnancies, although complications during pregnancy may occur. The chronic anaemia of thalassaemia intermedia can cause an increase in spontaneous abortions, pre-term labour and intrauterine growth retardation, while endocrine complications due to haemosiderosis are common. Folic acid deficiency is common in thalassaemia intermedia and occurs due to poor absorption, low dietary intake or, most significantly, an increased demand for folic acid from active bone marrow. During pregnancy, women with thalassaemia intermedia should be given oral folic acid supplementation (around 1 mg/day), and should be carefully monitored in order to assess the need for transfusion therapy and to avoid haemodynamic compromises (Taher, Ismaeel and Cappellini, 2006; Nassar, Rechdan, Usta and Taher, 2006).

Osteoporosis (also see chapter on osteoporosis) There is a high incidence of osteoporosis of the spine and hip in both sexes in thalassaemia intermedia. The severity increases with age and even young patients exhibit a spinal bone mineral density far below that of age-matched controls. Management consists of bisphosphonates and calcium supplementation with follow up bone-mass densitometries (Origa, Fiumana et al, 2005).

Pseudoxanthoma elasticum (PXE)

Iron overload

PXE is a rare hereditary connective tissue disorder, characterised by generalised degeneration of the elastic fibres with a

Just as in thalassaemia major, TI patients are susceptible to complications of iron overload.

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broad phenotypic expression. The clinical picture consists mainly of cutaneous, ocular and vascular manifestations; skin histopathology involves swollen, irregularly clumped and multiply-fragmented elastic fibres in the middle and deep reticular dermis, with secondary calcium deposition. This condition has been described as occurring in Ùhalassaemia.

Transfusion therapy and iron chelation Although transfusion therapy is not currently a routine treatment approach for patients with thalassaemia intermedia, it can afford significant benefits. The decision to initiate therapy should be based on the presence and severity of signs and symptoms of anaemia, including failure of growth and development. As the rate of iron loading is variable in thalassaemia intermedia, an assessment of liver iron concentration is advisable before initiating transfusion therapy. Patients with thalassaemia intermedia may benefit from an individually tailored transfusion regimen, compared with the regular transfusion regimens implemented in thalassaemia major, to help prevent transfusion-dependency. Alloimmunisation is a relatively common observation in thalassaemia intermedia, although the risk is decreased if transfusion therapy is initiated before the age of 12 months (Pippard, Callender, Warner and Weatherall, 1979; Mourad, Hoffbrand, SheikhTaha et al, 2003; Cappellini, 2001).

Management of thalassaemia intermedia There are a number of options currently available for managing patients with thalassaemia intermedia, including splenectomy, transfusion therapy, modulation of fetal haemoglobin production and bone marrow transplantation (Taher, Ismaeel and Cappellini, 2006; Cappellini, Cerino, Marelli and Fiorelli, 2001).

Splenectomy

Transfusions are indicated where the following are observed: ñ failure to thrive in childhood in the presence of significant anaemia; ñ emergence of bone deformities; ñ increasing anaemia not attributable to rectifiable factors; ñ evidence of a clinically relevant tendency to thrombosis; ñ presence of leg ulcers; ñ development of pulmonary hypertension; ñ delayed or poor pubertal growth spurt and ñ progressive splenic enlargement.

Splenectomy is no longer a major mode of management. However, the main indications for splenectomy include growth retardation or poor health, leucopenia, thrombocytopenia, increased transfusion demand and symptomatic splenomegaly. Splenectomy before the age of 5 carries a high risk of infection and is therefore not generally recommended.

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eligible for transplantation is complex and is related to both quality of life and expected survival time of the transplanted patient. This is particularly relevant in patients with thalassaemia intermedia, especially in those who are only mildly affected. In stable asymptomatic TI patients who do not require transfusions, bone marrow transplantation is not needed.

Modulation of fetal haemoglobin production Increasing the synthesis of fetal haemoglobin can help to alleviate anaemia and thereby improve the clinical status of patients with thalassaemia intermedia. Agents including cytosine arabinoside and hydroxyurea may alter the pattern of erythropoiesis and increase the expression of Á-chain genes. Erythropoietin has been shown to be effective, with a possible additive effect in combination with hydroxyurea. Butyrates are a further experimental category, still unlicensed and with difficult intake. Good responses have been reported; however, most patients complain of the difficulty of intake orally and intravenously. Further clinical evaluation is required to clarify the value of this approach (Taher, Ismaeel and Cappellini, 2006; Karimi, H. Darzi, M. Yavarian, 2005; Dettelbach and Aviado, 1985; Dixit, Chatterjee, Mishra et al, 2005; Perrine, Ginder, Faller et al, 1993; Cappellini, Graziadei, Ciceri et al, 2000; Olivieri, Rees, Ginder et al, 1997). (For more details, see Chapter 13: Alternative approaches to the treatment of thalassaemia.)

Recommendations for the management of thalassaemia intermedia Two major issues regarding the management of thalassaemia intermedia are 1) the approach and management of complications in adult thalassaemia intermedia patients and 2) preventing such complications in younger patients. A stratification of the management of TI between adults and young patients has therefore been established. The scheme for adult thalassaemia intermedia patients is as follows: ñ each patient to be reviewed separately and stratified by risk; ñ hydroxyurea introduced as a suitable initial approach; ñ transfusion and iron chelation therapy with deferoxamine subcutaneous infusion and concomitant steroids for protection from alloimmunisation are essential; ñ aspirin for stroke prevention, postsplenectomy and life-long anticoagulation in patients with a history of thrombotic events is a must; ñ liver MRI assessment of iron concentration (or liver biopsy if MRI is

Bone marrow transplantation Bone marrow transplantation is an established treatment for ‚-thalassaemia. Although marrow transplantation can lead to cure, the degree of its success depends primarily on the health and age of the patient. The decision as to which patients are

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unavailable) is important to determine liver iron status for future chelation.

Definition of ‚thalassaemia/HbE

There are no clear guidelines for the management of thalassaemia intermedia in the young. Thus, the authors recommend the following: ñ a guarded approach to the need for splenectomy and delay in initiating transfusion unless considered necessary based on the above mentioned indications; ñ early initiation of transfusion and iron chelation therapy if there is evidence of growth abnormalities, poor performance at school or a psychological impact secondary to facial deformities; ñ regular follow-up with echocardiodoppler for cardiac complications and initiation of therapy at earlier disease onset to prevent progression; ñ regular follow up of liver iron concentration with MRI or liver biopsy; ñ discourage smoking, prolonged immobilisation and the use of oral contraceptives or an intrauterine device.

Haemoglobin E has the clinical phenotype of a mild form of ‚-thalassaemia, and is most frequent in southeast Asia, particularly eastern Thailand and Laos. The combination of HbE with ‚-thalassaemia spans thalassaemia phenotypes, from a condition indistinguishable from thalassaemia major to a mild form of thalassaemia intermedia (TIF, 2002; Premawardhena et al, 2005). Clinically, ‚-thalassaemia/HbE may be classified into three categories, each of which has its own unique clinical management requirements:

Mild ‚thalassaemia/HbE Mild ‚-thalassaemia/HbE patients do not require treatment and rarely develop clinical problems. Haemoglobin levels may be as high as 9-12 g/dl. Care should be taken not to

See Table 2 for indications for transfusion and splenectomy. Indications for transfusion

Indications for splenectomy

Growth failure or poor performance at school

Growth retardation or poor health

Transient stressful conditions

Leukopenia

(e.g.pregnancy, infection) Symptomatic anaemia

Thrombocytopenia

CHF+PHT

Increased transfusion demand

Leg ulcers

Symptomatic splenomegaly

(Taher, Ismaeel and Cappellini, 2006)

Table 2: Indications for transfusion and splenectomy in thalassaemia intermedia

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confuse this group of patients with individuals having iron deficiency or with carriers of ‚-thalassaemia, by careful investigation of the red cell morphology, including iron status and haemoglobin electrophoresis (TIF, 2002; Premawardhena et al, 2005).

Severe ‚-thalassaemia/HbE Patients present with the clinical symptoms of thalassaemia major, including defective physical development, bone deformities including facial changes, anaemia, jaundice and hepatosplenomegaly. Haemoglobin levels can be as low as 4-5 g/dl. The clinical management of this group of patients needs to be addressed as in thalassaemia major (TIF, 2002; Premawardhena et al, 2005).

Moderately severe ‚-thalassaemia/HbE This group encompasses the majority of ‚thalassaemia/HbE patients. Most patients have steady haemoglobin levels of 6-7 g/dl. Clinically, these patients manifest symptoms similar to thalassaemia intermedia and normally do not require blood transfusions unless they develop infections precipitating further anaemia. Other complications such as iron overload may occur in these patients. Where this is the case, iron chelation therapy should be initiated. Patients in this group often have a somewhat shortened lifespan, but with careful monitoring and treatment can have an open-ended prognosis (TIF, 2002; Premawardhena et al, 2005).

Complications and management of ‚-thalassaemia/HbE Complications in ‚-thalassaemia/HbE patients depend on the category they belong to, as indicated above. The worst of the complications occur in the severe group, in which the clinical picture is similar to that ‚thalassaemia major. This includes the multitude of problems brought about by iron overload due to dependence on transfusions (see sections on complications in ‚thalassaemia major for further explanation).

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Stem Cell Transplantation

Figure 1). Class II patients have an 87% probability of survival and an 83% chance of disease-free survival, with a 3% risk of rejection and a 15% risk of non-rejection mortality (see Figure 2), while Class III patients have a 79% probability of survival and a 58% chance of disease-free survival, with a 28% risk of rejection and a 19% risk of non-rejection mortality (see Figure 3). (Centres performing transplants in patients with broadly similar characteristics have shown comparable outcomes [Lucarelli 1997].) In the case of Class III patients, the introduction of conditioning regimens containing less than 200 mg/kg of cyclophosphamide resulted in a significant decrease in transplant-related mortality, but with a concomitant increased risk of graft rejection. Among adults (aged >16), the probability of surviving a bone marrow transplant procedure is 66% with a 62% probability of cure, a 35% chance of transplant-related mortality and a 5% chance of returning to the pre-transplant thalassaemic condition (see Figure 4).

Outcome and patient selection Bone marrow transplantation from HLAidentical siblings has been increasingly adopted for the cure of haemoglobinopathies. Since 1981, a large clinical experience has been gained with more than 1,500 bone marrow transplants performed in centres around the world. Over that time, a number of factors – the use of cyclosporin, more effective treatment of cytomegalovirus infection, improved aseptic techniques and the evolution of systemic antibiotic therapy – have led to a remarkable improvement in the outcome of bone marrow transplantation procedures (Lucarelli, 1990).

Three patient classes have been identified on the basis of the following risk factors, which have been found to have a significant influence on posttransplant outcome: ñ inadequate iron chelation therapy, ñ presence of liver fibrosis and ñ hepatomegaly

Based on these outcomes, bone marrow transplantation in thalassaemia should be considered for patients at an early age or before complications due to iron overload have developed. However, a final decision must be based on an assessment of the relative advantages and disadvantages of bone marrow transplantation and conventional therapy, requiring the physician, patient and family to weigh the outcome and risks of each.

Patients in Class I have none of the above characteristics, patients in Class II have one or two, and patients in Class III exhibit all three characteristics. Among Class I children with thalassaemia major transplanted early in the course of the disease, the probabilities of survival and disease-free survival are 93% and 91% respectively, with a 2% risk of rejection and an 8% risk of transplant-related mortality (see

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There are several possible advantages to this approach. First, stem cells can be obtained easily at birth, and often in sufficient quantity for a successful donation â&#x20AC;&#x201C; thus avoiding the bone marrow harvest of a donor at a later age. Second, it has been suggested that graft versus host disease (GVHD) may be less severe when stem cells are obtained at this early point in life. Third, the routine collection of cord blood stem cells from all births would provide a wider pool of donors for BMT therapy.

HLA-matched sibling donors The general applicability of bone marrow transplantation is limited by the availability of a related HLA-matched donor. There is a onein-four chance that any given sibling will be HLA identical, with the likelihood of a thalassaemic patient having an HLA identical sibling donor varying according to family size.

However, the evidence of decreased GVHD using cord blood is not persuasive. And in many cases, the quantity of stem cells obtained is insufficient for engraftment in an adult recipient. Thus, while cord blood transplantation has been successfully used to treat some patients with thalassaemia (Miniero, 1998), its overall value in treating the condition has yet to be firmly established.

Matched unrelated donor transplantation Because most patients with thalassaemia do not have a compatible sibling donor, there is interest in using unrelated but otherwise matched donors. Unfortunately, the complication rates of transplants using matched unrelated donors are generally much higher than with sibling matched transplants. It is hoped that with continuing improvements in matching techniques, complication rates will be reduced to acceptable levels. There has been some application of transplantation using matched unrelated donors in thalassaemia, suggesting that if unrelated donors are from a closely related genetic background the outcome may be improved (Dini, 1999; Miano, 1998). Experience so far is limited, however.

Mixed chimerism Persistence of residual host haematopoietic cells, normally termed mixed chimerism, frequently occurs after bone marrow transplantation in â&#x20AC;&#x161;-thalassaemia (Andreani, 2000). Reduction of the dose of busulfan or cyclophosphamide in the conditioning regimens produced higher rates of mixed chimerism â&#x20AC;&#x201C; a risk factor for graft failure. None of the patients showing full donor engraftment rejected the transplant, while 29% of patients with mixed chimerism rejected the graft within two years of marrow infusion. Nevertheless, a condition of long-term (> 2 years) persistent mixed chimerism has been observed after successful BMT in thalassaemia. This

Cord blood transplantation The use of stem cells obtained from umbilical cord blood collected at the time of delivery has recently received considerable interest.

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observation may have a significant impact on the design of future bone marrow transplant strategies.

Post-transplant follow-up Post-transplant clinical follow-up of BMT is particularly important. Within the first year, careful monitoring of haematological and engraftment parameters, infectious complications and graft versus host disease is essential. Long-term follow-up is of particular interest with respect to monitoring the evolution of multi-system problems (iron overload, pubertal development, growth, endocrine deficiencies) related to the primary disease. A number of reports indicate that iron overload, chronic hepatitis, cardiac function and endocrine deficiencies can be more easily managed after transplant, sometimes permitting the healing of damaged organs. It is particularly important to remove excess iron after transplant. This can usually be achieved by repeated venesection (6 ml/kg blood withdrawn at 14-day intervals) (Angelucci 1997).

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Figure 1:

Figure 3:

Figure 2:

Kaplan and Meier probabilities of survival, event-free survival, rejection and non-rejection mortality in 119 Class I thalassaemic patients aged less than 17 years.

Kaplan and Meier probabilities of survival, event-free survival, rejection and non-rejection mortality in 126 Class III thalassaemic patients aged less than 17 years.

Figure 4:

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Kaplan and Meier probabilities of survival, event-free survival, rejection and non-rejection mortality in 291 Class II thalassaemic patients aged less than 17 years

Kaplan and Meier probabilities of survival, event-free survival, rejection and non-rejection mortality in 115 adult thalassaemic patients (aged more than 16 years).

Alternative Approaches to the Treatment of Thalassaemia

recovery from bone marrow suppression after the use of cytotoxic drugs, attention has focused on the possible role of cytotoxic agents as therapies in the treatment of serious haemoglobin disorders. Several cytotoxic agents that alter the pattern of erythropoiesis, favouring the expression of foetal (Á)-globin genes and so increasing the number of red cells containing HbF (F-cells), have been explored over the past 20-25 years (Pace and Zei, 2006; Fathallah and Atweh, 2006; Gambari and Fibach, 2007).

There is currently no definitive treatment for any of the serious haemoglobin disorders, other than bone marrow transplantation—an option available only to a small minority of patients that have a suitable donor and are in good clinical condition. Another, promising, approach involves the use of therapeutics to definitively correct the globin chain imbalance in ‚-thalassaemia, by re-activating the foetal globin genes.

Modulation of fetal haemoglobin

The demethylating agents 5-azacytidine and decitabine have been administered to a few ‚-thalassaemia patients with good responses, raising total haemoglobin levels by a mean of 2.5 g/dl above baseline and clearly prolonging the lives of end-stage patients (Lowrey, 1993; Dunbar, 1989; Ley, 1982). The mutagenic potential and instability of formulations of 5-azacytidine have limited its investigation, but higher oral doses of decitabine have been effective in baboons (Lavelle, 2006), and studies are planned in selected patients.

Foetal haemoglobin is the predominant non· globin produced in humans until around six months of age, when it is typically suppressed and the production of ‚-globin is increased. This pattern is the norm even when the genes are mutated, as in ‚thalassaemia. Patients with ‚-thalassaemia who continue to produce high levels of foetal globin, such as those with Hereditary Persistence of Foetal Haemoglobin, have less globin imbalance and less severe anaemia.

Hydroxyurea has been studied in HbE/ ‚thalassaemia patients, with lower responses but reduced haemolysis (Fuchareon, 1996; Zeng, 1995). Hydroxyurea has been less beneficial in thalassaemia intermedia than in sickle cell disease, in which the number of painful crises was reduced and overall health indicators improved. The lesser benefits in thalassaemia are perhaps due to the fact that the cytostatic effects of hydroxyurea are limited in the disease.

The therapeutic stimulation of foetal globin could therefore benefit many patients, even rendering some transfusion independent. Several candidate therapies now offer the potential to correct or modulate the underlying pathology.

Other agents Erythropoetins (EPOs) have increased haemoglobin levels significantly in some patients with thalassaemia intermedia, even eliminating transfusion requirements in some

Cytotoxic agents Following observations that foetal haemoglobin synthesis is reactivated during

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(e.g. sodium 2,2-dimethybutyrate) (Boosalis, 2001; review Perrine, 2005). Select hydroxamic acid derivatives have had high activity in transgenic mice (Cao, 2005).

children. EPOs may thus be particularly helpful in patients with relatively low levels of endogenous erythropoietin for their degree of anaemia (Bourantas, 1997; Nisli, 1996 and 1997; Rachmilevitz, 1998; Singer, 2003). EPO promotes survival of red blood cells and may counteract the rapid cell death (apoptosis) caused by precipitation of excess ·-globin chains in ‚-thalassaemia (review Silva, 1996; Perrine, 2005).

The mechanisms by which short chain fatty acids stimulate Á-globin production are being elucidated. Some new derivatives displace a repressor complex and cause acetylation specifically of the foetal globin gene promoter (Mankidy et al, 2006). Phenylbutyrate and butyrate cause general histone hyperacetylation, which inhibits cell proliferation, and are counter-productive in thalassaemia, requiring limited exposure (Pulse therapy). Butyrates have induced fetal globin production in approximately twothirds of patients with diverse molecular mutations and raised total haemoglobin levels an average of 2-3 g/dl above baseline when given intermittently to avoid antiproliferative effects (review Perrine, 2005). As differences in drug metabolism contribute significantly to responsiveness to any drug, these will certainly apply in the highly diverse thalassaemia syndromes. New generation agents which promote erythroid survival, and can be given daily, offer significantly more potential benefit than the first generation prototypes.

Short chain fatty acid derivatives Short chain fatty acid derivatives induce activity from the foetal globin gene promoter, resulting in two-to-six-fold higher foetal globin mRNA in some patients, especially those who have at least one ‚0thalassaemia mutation and EPO levels >140 mU/ml (Collins, 1995; Perrine, 2005). Their acceptable toxicity profiles add to their potential as long-term therapeutic agents. Several preliminary trials with intravenous butyrate and oral phenylbutyrate compounds have shown increases in foetal and total haemoglobin levels in patients with thalassaemia intermedia, while a few previously transfusion-dependent thalassaemia major patients have been maintained transfusion-independent on home therapy for 5-7 years. Isobutyramide has induced foetal globin and reduced transfusion requirements in thalassaemia intermedia and major (Cappellini, 2000; Reich, 2000).

Combination therapy Although pharmacological induction of fetal haemoglobin in transfusion-dependent patients with thalassaemia will require highpotency induction of foetal globin, weaning of transfusions to allow renewal of patients’ own erythropoiesis, adequately high EPO levels to promote eyrthroid cell survival and iron availability for erythropoiesis, there is expectation that some of the agents, used in combination or properly scheduled, could result in complimentary effects and render even severe patients transfusion-

The most effective compound thus far is arginine butyrate, although this has the disadvantage of requiring intravenous infusion due to its rapid metabolism. Oral derivatives that persist for many hours after a single dose and which also stimulate erythroid cell proliferation and survival, similar to EPO, will enter clinical trials soon

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independent. For example, a demethylating agent and butyrate had synergistic activity, much higher than additive effects, in experimental studies (Constantoulakis, 1989). Such combinations offer excellent potential for patients with diverse syndromes.

An approach to rational combinations can now be based on a patientâ&#x20AC;&#x2122;s baseline HbF, total haemoglobin and EPO levels (review Perrine, 2005). Clinical trials should be planned to find optimal drug combinations for different patient subsets.

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Gene Therapy: Current Status and Future Prospects

vector. The corrected cells are then returned to the patient, who in the meantime has undergone chemotherapy (as in a donorderived bone marrow transplant) to partially or completely destroy their diseased bone marrow (Persons and Tisdale, 2004).

The idea of using gene therapy to treat the haemoglobinopathies (thalassaemia and sickle cell disease) is, in principle, straightforward. Red blood cells (RBC) are continuously replenished by bone marrow haematopoietic stem cells (HSC). Therefore, the stable transfer of a normal functioning copy of a ‚globin therapy gene unit into the patient’s own HSC would result in the generation of normal rather than diseased RBC for life. (Note: no donor bone marrow is needed).

Early studies with LCR-‚-globin gene retroviral vectors based on the mouse MoLV virus and using an ex vivo procedure in animal models, provided good proof of principle. However, it proved very difficult to accommodate LCR-‚-globin gene units within MoLV retroviral vectors and manufacture them. In addition, the LCR-‚-globin therapy gene units that could be incorporated into this vector system were ineffective at producing a consistent and sufficiently high level of ‚-globin protein to be of therapeutic value (Antoniou and Grosveld, 1999). However, a major breakthrough occurred in 2000, when the laboratory of Prof Michel Sadelain reported work involving the testing of an LCR-‚-globin therapy gene unit within a class of retrovirus known as an HIV lentiviral (LV) vector (Figure 1; May et al, 2000). Prof Sadelain showed for the first time that the LV vector can readily accommodate a larger and more efficient version of the ‚-globin therapy gene linked to the three most powerful LCR elements (HS2, HS3, HS4), and that application of this vector in an ex vivo bone marrow transplant procedure could completely cure or rescue the ‚-thalassaemia condition in mouse models of this disease (May et al, 2000; Rivella et al, 2003).

A number of major discoveries and technical advances in gene therapy over the last 20 years, particularly since 2000, mean that, at long last, gene therapy for the haemoglobinopathies looks a serious possibility in the not too distant future. In 1987, a group led by Prof Frank Grosveld discovered the master regulator of the ‚globin gene family, known as the ‘locus control region’ (LCR). It was found that linking the LCR to a ‚-globin gene unit enables the gene to be efficiently and reproducibly switched on, and to produce a sufficiently high level of ‚-globin protein to be of therapeutic benefit, if reproduced in a gene therapy context (Levings and Bungert, 2002; Stamatoyannopoulos, 2005). The stable introduction of the LCR-‚-globin therapy gene unit into the patient’s HSC is via a retrovirus delivery vector, resulting in the permanent splicing or integration of the therapy gene into the HSC DNA, which is then retained for life. Overall, the gene therapy protocol employs an ‘ex vivo’ procedure. HSC are isolated from the patient’s bone marrow and infected or transduced with the LCR-‚-globin retroviral

Since then, a number of groups in the US and Europe have built their own versions of the LCR-‚-globin gene LV vector (Persons and Tisdale, 2004; von Kalle C et al, 2004; Sadelain et al, 2006). The smallest version of the LCR-‚-globin gene LV vector has included only LCR elements HS2 and HS3 in its design,

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Figure 1: Illustration of how a lentiviral vector containing a b-globin therapy gene unit is constructed from the normal (wild-type) HIV virus. A. Structure and gene organisation of wild-type HIV virus. B. Replacement of the normal genes of the wild-type HIV virus with the Locus Control Region-‚globin therapy gene unit produces the lentiviral vector. Note: combinations of locus control region elements HS2/HS3/HS4 or HS2/HS3 have been employed.

gene LV vector include: (i) reproducibility of function of the vector; at present there is significant variability in the expression of the LCR-‚-globin therapy gene (including its complete switching off), which is dependent upon the site where the LV vector has integrated within the HSC DNA (e.g. see May et al, 2000; Miccio et al, 2006; Han et al, 2007); (ii) insertional mutagenesis: the integration of the LCR-‚-globin gene LV vector into the HSC DNA has the potential to disrupt host cell gene function causing, in the extreme situation, a leukaemia-type condition (von Kalle C et al, 2004), as has been observed in clinical trials using retroviral vectors for gene therapy of X-linked severe combined immune deficiency (SCID-X1; see Nienhuis et al, 2006), which also targets the HSC of the patient. Some researchers have

which has significantly improved the ease of vector manufacture (Miccio et al, 2006). In all these cases, researchers have shown good efficacy in rescuing disease in mouse models of ‚-thalassaemia or of sickle cell disease. In addition, some groups have shown that, under laboratory conditions, transduction of human HSC derived from bone marrow of severe ‚-thalassaemia major patients with the LCR-‚-globin gene LV vector can correct the globin chain imbalance in resulting RBC (Persons and Tisdale, 2004; Sadelain et al, 2006; von Kalle C et al, 2004; Roselli et al, 2006). Remaining problems that need to be addressed in order to improve both the effectiveness and safety of the LCR-‚-globin

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al, 2005). Up to the end of 2006, two patients with ‚-thalassaemia had been treated. It is too early in the trial to know if any benefit has been derived.

therefore included the chicken b-globin LCR element cHS4 in their LV vector design to try and ‘insulate’ the LCR-‚-globin gene unit, which has led to some improvement in the reproducibility of functioning (Persons and Tisdale, 2004; von Kalle C et al, 2004; Sadelain et al, 2006). In addition, it has been suggested that the cHS4 element may act to shield host genes within the HSC from interference by the LCR-‚-globin therapy gene unit and therefore promote safety, although this has yet to be formally demonstrated.

The trial has not been without controversy, mainly related to the use of a high-risk full chemotherapy-conditioning programme as part of a protocol whose success is still far from certain, let alone in relation to what is currently achievable with a sibling-donor bone marrow transplant.

We eagerly await the outcome of these studies, as well as the commencement of future trials with LV vector designs with higher efficacy and safety profiles.

These studies led to the commencement of the first Phase I/II gene therapy clinical trial for the haemoglobinopathies in 2006. The trial is led by Prof Philippe Leboulch in Paris and aims to treat five ‚-thalassaemia and five sickle cell disease patients within the age range of 5-35 years. The protocol, as expected, involves an ‘ex vivo’ approach, with patients receiving a full chemotherapyconditioning programme with Busulfex to destroy their diseased bone marrow (Bank et

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Psychological Support in Thalassaemia

The success of management of thalassaemia is based, to a great extent on the establishment of a therapeutic alliance between caring staff and the patient throughout the course of the disease. Because of the disease-oriented emphasis of medical education, many health professionals find it difficult to come to terms with the psychological demands of treating chronic inherited diseases. This can be made more difficult in thalassaemia because patients often express strong negative feelings, which can hamper communication. Furthermore, after many years of treatment, patients and family may be better informed about the illness than non-skilled health professionals— a factor that can undermine the health professionals’ perceived role. Taken together, these factors can make honest, in-depth communication, which is vital to successfully coping with thalassaemia, extremely difficult to maintain.

Why is psychological support so important? It is now universally recognised that thalassaemia, like other chronic diseases, has important psychological implications. The way in which the family and the patient come to terms with the disease and its treatment will have a critical effect on the patient’s survival and quality of life. Without an understanding and acceptance of the disease and its implications, the difficulties of lifelong transfusion and chelation therapy will not be faced, leading to an increased risk of disease complications and poorer survival. A key role for treating physicians and other health care professionals is to help patients and families to face up to the difficult demands of treatment, while maintaining a positive role.

The psychology of inherited chronic disease

Adherence to treatment is a basic goal, but a general acceptance by the patient of his/her own condition constitutes the key to normal development from childhood to adulthood. Monthly contact with a local thalassaemia centre from the first years of life allows doctors and other members of the team to act as a reference point for the patient’s overall state of health, including general attitude and well-being. In addition, this regular interaction provides to the whole staff, and in particular to the treating physician a good opportunity to promote the patient’s physical, emotional and social development, taking on several characteristics of the traditional ‘family doctor’ as guardian of the patient’s overall wellness.

Every genetic disease, regardless of its aetiology, implies a sense of guilt that may interfere with the primary parent-infant relationship. As its clinical manifestations develop in the first year of life, the disease can have also a negative impact on the parent-child relationship. Moreover, the treatment is emotionally demanding, as transfusion and chelation therapy require repeated invasive procedures and hospital visits. Chronicity is a powerful source of emotional problems that intensify at each significant

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balance. It can also be extremely rewarding for the healthcare professional, both in medical and emotional terms. Where a healthcare professional manages to maintain a constant dialogue with his/her patients, s/he will often discover in patients with thalassaemia skills that greatly surpass those of their peers when facing the great challenges of life such as birth/death, love/loneliness, opportunities/limits.

developmental stage of the patient’s life. Patients can feel that they are different, limited or isolated. Their state of mind can shift rapidly from depression to anger and vice versa. Health workers must be prepared to accept this shift and to help patients deal with these feelings, finding a way to their own ‘normalisation’ that implies different individual styles in adult life. Overall, good treatment facilitates personal development and achievement of targets in life, while poor care makes such development difficult or unpredictable.

Caring for a ‘normal’ development

Communication: healthcare professionals with patients

Settings and methodology for discussion are important all along the course of the disease, but are mandatory at crucial milestones in the patient’s and parents’ experience: At the onset and during the first period, communication work is carried out with parents, but the child has to be included as soon as possible. From as early as three to five years of age, young patients begin to ask crucial questions about the duration of care and possibilities of a cure. These should be dealt with sensitively and honestly. Separate interviews with patient and with parents are recommended in the approach to adolescence, while in adulthood individual interviews with the patient are essential.

Healthcare professionals should seek, as far as possible, to: ñ Listen – to be interested in the patient’s emotional and real experiences ñ Accept – to respect the patient’s point of view and be sensitive to the timing of personal communication ñ Share – to be consistently close to the patient’s positive and negative feelings ñ Understand – at an emotional and not simply an intellectual level ñ Maintain boundaries – to give help and relief, but keeping in mind his/her role as a physician

Communication of diagnosis As exemplification, it is useful to focus on communication of diagnosis, because it is the natural starting point of the whole course of disease and may mark permanently (positively or negatively) the therapeutic relationship.

Good communication with healthcare professionals can be extremely beneficial for the patient, helping him/her to cope better with thalassaemia and to maintain a sense of

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transfusion interval may allow these symptoms to recur. This gives the patient the experience of instability and doubt about his/her physical capabilities. Moreover, because of the risk of transfusiontransmitted diseases, fears of being contaminated are ever-present and may be intense for real reasons (high risk of transmission) or due to the patient’s emotional state. This fact helps to sustain ambivalence towards therapy.

In trying to establish an ideal setting, the following points should be considered: ñ The room chosen and time allocated aim to provide an atmosphere that will sustain hope and optimism; and not make the patient feel depressed or misled. ñ The diagnosis should be discussed with both parents together, allowing ample time to listen to their concerns and to respond to their questions, worries and concerns. ñ Information must be sincere, complete and repeated as often as needed. The weight of negative emotions may be so great that parents may appear confused even after complete information has been given more than once. ñ In the months following diagnosis, the discussion must be renewed, with the same attention given to the setting, and preferably with the same doctor to preserve continuity.

In any case, the need for periodic transfusions testifies that vital energy comes from other people, implying a dependence at the physical level that can invade the mental level, limiting personal development. In addition, transfusion therapy does not cure; it merely provides a monthly “patch” for the anaemia, giving life and well-being but also (even if safe from infection) causing iron overload, which necessitates additional treatment that is also lifelong. This combination of advantages and disadvantages of transfusion finds a parallel in patients’ psychological reactions to their treatment.

The same attention to setting must be provided at any significant step, in order to better support patient/parents in coping with distressing information.

Regularly transfused patients can experience positive feelings, such as gratitude for receiving life, and negative ones such as fear and anger at being ‘ruined’.

Psychological impact of anaemia and transfusion

Psychological aspects of chelation therapy

Serious anaemia will cause the patient to feel weak and vulnerable. Maintaining an adequate haemoglobin level through optimal transfusion therapy (see Chapter 2: Blood Tranfusion Therapy in ‚-thalassaemia Major) eliminates these symptoms and reduces the patient’s anxiety about death. However, the decrease in haemoglobin during the

Treating staff should be very familiar with the emotional aspects of chelation, as compliance with therapy determines prognosis (see Table 1).

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Psychological aspects

Subcutaneous chelation

Oral chelation

Aggression ‘Patch’

Body image damage

Daily reminder

Feeling different Lack of check

Constant commitment

Table 1

Time and movement restrictions related to the use of the pump generate feelings of being different and restricted.

In general, chelation is a psychologically demanding therapy, because: ñ Iron chelation does not cure but rather treats the main complication of the basic therapy (transfusion), as ‘the patch of another patch’. ñ Like transfusion, it is a reminder of one’s illness, and even more on a daily basis. ñ Optimal chelation starts during the first years of life. ñ Effectiveness of the drug cannot be checked quickly and directly by the patient. So compliance is a function of trust; that is to say, it reflects the quality of the treating staff-patient relationship and a belief in long-term benefits.

Parents may: ñ Not yet have overcome the shock of diagnosis. Administering the infusion can be painful since they feel responsible for their child’s discomfort. ñ Use chelation as a control tool when the child reaches adolescence. Patients may: ñ Adopt attitudes of out-and-out refusal, feeling ‘tortured’ instead of cared for. ñ Exploit any opportunity or excuse to skip a day’s infusion. ñ Repeatedly select the same sites for needle insertion, so trying to reduce the body image damage.

Subcutaneous chelation Parenteral treatment implies a small act of aggression, either self-directed or inflicted by the patient’s loved ones. Skin punctures from the needles cause body image damage. The patient may feel ‘as full of holes as a colander’.

Physicians may: ñ ‘Bargain’ with the patient, underprescribing desferrioxamine, more for psychological reasons than on the rationale of iron balance.

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ñ Promote the shift from parent to patient management as early as possible. Many patients with thalassaemia can begin to take control of their medication regimen from six years of age. The early initiation of self-management limits overprotection and stimulates autonomy in the young patient. It also gives relief to parents and ultimately improves the quality of life of the whole family. ñ Encourage patients to feel a sense of reward for achieving mutually agreed therapeutic goals. ñ Remember that long-term high compliance fosters good capability and self-reliance and is a key positive factor in maintaining emotional well-being.

ñ Tacitly encourage non-compliers to treatment in order to avoid the development of negative psychological states. While the underlying motivation for all the above reactions or attitudes is generally a desire to provide relief from the patient’s discomfort and to make him/her feel better, the long-term effects of such behaviour are harmful for the patient’s physical health and emotional well-being.

Oral chelation Oral administration simplifies significantly many practical aspects of chelation management with Deferrioxamine. For some patients (and some healthcare professionals), a shift to oral chelation may seem ‘the solution to every problem’. In fact, however, oral chelation only helps with the issues of daily ‘holes’ to the skin and consequent damage to body image. Patients taking oral chelators must still face the daily feeling of being different and will still lack the means to immediately and quickly assess the impact of treatment and in this context it will remain difficult for some patients even on oral chelation to maintain adequate compliance.

Psychological impact of complications During adolescence or young adulthood various complications may occur. The psychological implications of such complications lie in their degree rather than their onset. In general, asymptomatic complications do not require medication and do not interfere heavily with quality of life. However, when a serious complication such as heart disease or diabetes appears, the patient undergoes a period of psychological readjustment. S/he has to integrate the hopes, enthusiasm and wishes typical of youth with a damaged physical state and medical features typical of old age. In such a situation, the inadequately supported patient may feel ‘hopelessly ruined’, giving up on health and continued therapy.

Recommendations: ñ Define and resolve the practical aspects of optimal chelation (see Chapter 3: Iron Overload). ñ Avoid judging, reprimanding or threatening the patient. ñ Pay due attention to the psychological aspects of the disease, as underestimating these undermines the effectiveness of the treating staff-patient relationship with an increased risk of treatment failure. ñ Be involved in supporting, instead of simply insisting or prescribing.

Table 2 outlines the impact of the most common complications (at moderate/severe stage) on patient emotional balance.

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Complication

Treatment burden

Influence on daily life

Feeling of difference

Dependence

Feeling of damage

Death anxiety

Hypogonadism

+++

Hypothyroidism

Hypoparathyroidism ++

Osteoporosis

+++

-/+++

+++

Diabetes Heart disease Hepatitis Table 2

Beginning a new job or an important loving relationship can increase feelings of inadequacy and fragility. Sometimes an emotional crisis occurs and psychological support may be required.

In contrast to the past, recent advances in iron chelation therapy have led to a dramatic progress in survival, in saving patients from acute life-threatening heart failure, and generally in improving quality of life. Treating staff must maintain a positive perspective and support a patient’s sense of hope. Even in very serious cases, it is still possible to deal with suffering by sharing and working together to find ways of accepting new limits inherent to a given situation.

Treating staff should accompany the patient along his/her life path, while respecting his/her fragilities, sensitivity, and supporting resources. The most common mistakes on the part of healthcare professionals is that they are being overprotective or disinterested. On the other hand, special care should be taken in preventing intrusions into the patient’s privacy.

Challenges for the adult patient

Summary of psychological goals

If the disease is fully compensated, physical conditions allow the patient with thalassaemia to make his/her choices of adult life without any restrictions or limitations. Even in this ideal state, however, at a psychological level young adults with thalassaemia can run into more difficulties than peers in coping with the tasks of adult life, particularly those implying independence and responsibility.

In terms of the psychological care of the patient, healthcare professionals should aim to: ñ Provide information that promotes understanding of the illness ñ Help patient and parents to talk and to express feelings about the illness

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It is clearly not possible for a health professional to provide all the above support if the organisation of his/her healthcare system does not provide him or her with the opportunity to work with patients on a longterm basis. The ‘rotation’ of experienced professionals to different wards can seriously undermine a patient’s psychological wellbeing, treatment and prognosis. Appropriate psychological support therefore not only requires motivated and able clinicians, but also presupposes an organisational structure that allows for the successful delivery of optimal and comprehensive care.

ñ Help the patient to accept the illness and to take care of him/herself ñ Maintain realistic hopes ñ Facilitate a ‘normal’ lifestyle and encourage self-esteem ñ Support the full development of an adult life Putting these goals into practice requires health professionals to be: ñ Open-minded about psychological aspects of having and treating inherited disease ñ Trained in normal psychosocial development from childhood to adulthood ñ Sensitised to the special issues of this chronic hereditary disease ñ Available to accompany and support the patient throughout his/her life path

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General Health Care and Lifestyle in Thalassaemia

This right should be considered before other points of view (i.e. those of parents, relatives, school, hospital and official bodies).

Lifestyle If the disease is fully compensated by ideal treatment, an individual with thalassaemia major can enjoy a near-normal lifestyle and experience regular physical and emotional development from childhood to adulthood, including parenthood.

Staff should: ñ Assure confidentiality of patient identity and data in all circumstances, trying to be compliant with local, International laws and rules on privacy, if not against patient’s rights. ñ Help parents to be aware of diseaserelated issues early on in the patient’s life (e.g. teaching parents to decide with the child, from the age of 6, if and how to communicate with the school about thalassaemia) ñ Help the patient to build up a realistic and balanced position between being open and being secretive about the disease

Treating staff should promote such a progression by trying to reduce as far as possible the degree to which the disease interferes with the patient’s personal and social life. Where the disease cannot be fully compensated with proper transfusional schemes, the obstacles to a normal lifestyle should be taken into account with a realistic but positive approach, based on informing and encouraging the patient, and reviewing limitations on time and treatment schedule.

School If the patient’s haemoglobin levels are maintained close to the values recommended in this book, no relevant interference with academic performance should be seen. Where the haemoglobin level is allowed to fall too low, the patient may have difficulty in school. However, individual variability is wide.

From a practical point of view, treating staff should: ñ Manage treatment and monitoring schedules so as to minimise any unnecessary impact on normal daily activity ñ Be aware of the particular psychological aspects of health care for this chronic condition (see Chapter 15: Psychological Support in Thalassaemia)

Although normal transfusion and follow up schedules many require a number of absences, these should not be to the extent where the patients’ school performance is negatively affected.

Confidentiality vs. openness

Home Splenectomised patients should be warned about the risk of having pets at home, due to the possibility of bites and this increased risk of septicaemia (Capnocytophaga

The patient should have the right to decide if, when and with whom to talk about the disease. 149

canimorsus-associated). Additional care in preventive measures may be required in some areas due to specific infection risk (see the example of Pythiosis in Thailand in Chapter on Infections). Patients with active viral hepatitis or other viral infections should take general measures to minimize or prevent the risk of transmission to the family.

Sexual and reproductive life Differences in appearance (facial features, height, and skin colour) may affect selfconfidence and participation in social life. In adolescence, the absence or delay of sexual development is regarded by patients as particularly stigmatising. Timely optimal treatment of hypogonadism limits these effects. Carriers of a viral infection must also address additional uncertainties as regards safe sexual behaviour.

Work In general, it is important for patients to have a positive attitude towards their ability to work. In chronic diseases a shift to overprotection is a frequent problem for all people involved (parents, treating staff, patient association and patients themselves). This may be partially useful when treatment possibilities are scarce and the physical conditions of the patient are poor. However, well-treated patients generally do not face difficulties in performing work as a direct result of their disease.

The general improvement in the health of patients with thalassaemia, particularly in industrilized high income (HDI) countries, means it is now possible for them to have children spontaneously or by induction of pregnancy. Patient attitudes to parenthood may range from unnecessary feelings of psychophysical inadequacy to an underestimation of the risks and difficulties involved. Treating staff should help the patient and his/her partner to achieve a balanced position. The decision as to whether to induce pregnancy medically can be difficult, and the patientâ&#x20AC;&#x2122;s and partnerâ&#x20AC;&#x2122;s expectations, the risks of pregnancy and the long-term prognosis of the patient must be seriously taken into consideration. Exhaustive counselling is necessary to explore these issues in a sensitive but thorough manner.

Depending on the country, thalassaemia may be recognised as causing a certain degree of disability, with resulting benefits and special employment facilities. While these may help the family and the patient from a practical viewpoint, care should be taken that these entitlements do not interfere with a positive attitude to normality, self-esteem and the ability to work (see Chapter 15: Psychological Support in Thalassaemia). Symptomatic heart disease and osteoporosis may cause difficulties for patients in performing certain physical tasks and specific advice in limiting at-risk activities should be provided.

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in the country to be visited should be obtained, and appropriate vaccination and prophylaxis obtained in advance. Particular attention should be paid to the prevalence of malaria (see below).

Routine Health Care Vaccinations

There is no reason for patients with thalassaemia to skip or delay standard recommended vaccinations.

Blood Ideally, a patient should always receive blood transfusions at the same place. Travel plans should be coordinated with the patientâ&#x20AC;&#x2122;s transfusion schedule, in order to avoid receiving transfusions elsewhere, particularly if visiting areas where blood supplies carry a high risk of infection.

Additional vaccinations for patients with thalassaemia are discussed in the Chapter on Infections.

Dental care Patients who are untransfused, undertransfused or who begin transfusion at a later stage in the disease may have some malformations of the facial bones due to marrow expansion. This can affect growth of the teeth and cause malocclusion. Orthodontic care may be successful in improving masticatory function and/or correcting unaesthetic dental appearances. Orthodontic schedule must take account of the peculiar characteristics of bone disease in thalassaemia in order, to prevent tooth instability or loss. The degree of osteoporosis of maxillary bone should guide the treatment schedule.

Chelation Travelling and holidays should be organised so as not to interfere with regular chelation and treating staff should not indulge the â&#x20AC;&#x2DC;poor guyâ&#x20AC;&#x2122; attitude. However, requests to comply with adjustments in the chelation schedule to minimise interruptions must also take into account some practical aspects (e.g. an adolescent planning the first camp holidays with peers), and relational aspects (i.e. secrecy or open communication about the disease).

Splenectomy The splenectomised patient should always travel with antibiotics, to assure prompt medication in case of fever, sepsis or animal bites. Treating staff should discourage travel where the risk of malaria is significant, as this disease may be more serious in splenectomised subjects.

Travelling Travel carries a degree of risk, which increases if the patient cannot receive expert local treatment. If a patient is travelling to a remote country, it is vital that adequate travel insurance is obtained so that if serious complications develop, s/he can be flown home immediately, with provision of any necessary medical assistance. If the patient plans a trip, treating staff should, as far as possible, give information about the closest hospital with services and experience in the management of thalassaemia. As for any traveller, detailed advice about infection risks

Nutrition General

Patients with thalassaemia do not have specific dietary requirements, unless they have special

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prescriptions. In general, a restrictive diet is easy to be prescribed but difficult to be maintained over the long term. In thalassaemia, the patient already has a heavy treatment schedule and it is counterproductive to add further restrictions without the likelihood of clear benefit.

Calcium

Many factors in thalassaemia promote calcium depletion. A diet containing adequate calcium (e.g. milk, cheese, dairy products and kale) is always recommended.

During growth, a normal energy intake with normal fat and sugar content is recommended. During adolescence and adult life, a diet low in highly refined carbohydrates (sugar, soft drinks, snacks) may be useful in preventing or delaying the onset of impaired glucose tolerance or diabetes.

However, nephrolithiasis is seen in some adults with thalassaemia major, and calcium supplements should not be given unless there is a clear indication, instead a low oxalate diet should be considered. Vitamin D may also be required to stabilise calcium balance, particularly if hypoparathyroidism is present. In case of liver disease, the activated form should be preferred. However, if supplements are used, careful monitoring is required in order to prevent toxicity.

There is no clear evidence that a diet is beneficial in preventing or managing liver disease, unless at late stages.

Iron Increased iron absorption from the intestinal tract is characteristic of thalassaemia. The amount depends on the degree of erythropoiesis, the haemoglobin level and other potential independent factors. Drinking a glass of black tea with meals reduces iron absorption from food, particularly in thalassaemia intermedia (de Alarcon, 1979). However, there is no evidence that iron-poor diets are useful in thalassaemia major; only foods very rich in iron (such as liver and some ‘health drinks’ or health vitamin cocktails) should be avoided. Patients with thalassaemia should never be given iron supplements. Many baby foods, breakfast cereals and multivitamin preparations contain added iron, along with other vitamin supplements. The patient should therefore make a habit of reading labels carefully, seeking expert advice if necessary.

Patients with thalassaemia should not take additional calcium or vitamin D unless prescribed by their medical practitioner.

Folic acid Patients with thalassaemia who remain untransfused or are on low transfusion regimens have increased folate consumption and may develop a relative folate deficiency. Supplements (1mg/day) may be given if this occurs. Patients on high transfusion regimens rarely develop this condition, and usually have no need for supplements.

Vitamin C Iron overload causes vitamin C to be oxidised at an increased rate, leading to vitamin C deficiency in some patients. Vitamin C may increase the ‘chelatable iron’ available in the body, thus increasing the efficacy of chelation with desferrioxamine. However,

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hepatocarcinoma is significantly raised. Excessive alcohol consumption also results in decreased bone formation and is a risk factor for osteoporosis. In addition, alcoholic drinks may have unexpected interactions with medication.

there is currently no evidence supporting the use of vitamin C supplements in patients on deferiprone, deferasirox or combination treatment. Indeed, vitamin C ingestion may increase iron absorption from the gut, labile iron and hence iron toxicity. Therefore, supplements should only be considered for patients on desferrioxamine (see Chapter on Iron Overload).

Smoking Cigarette smoking may directly affect bone remodelling which is associated with osteoporosis and is related to adverse effects on the general health.

Some drugs, such as aspirin and throat lozenges, as well as certain ‘health foods’, may contain vitamin C and should be avoided. A diet rich in fresh fruits, including citrus fruits and vegetables, is recommended.

Drug abuse In many countries, drug abuse is common among adolescents and young adults. For an individual with a chronic disease, drug abuse can be a serious threat to an already challenging condition, upsetting the delicate balance of factors affecting physical and mental health. Treating staff should aim to help the patient maintain such a position, bearing in mind the challenges an adolescent patient is likely to face. A key danger is that— as with many adolescents—drug abuse may be seen as a compensatory way to be popular among peers or to ‘fit in’. For young people with thalassaemia, feelings of dependence, difference and anxiety can push patients to seek ‘normality’ through an abuse habit.

Vitamin E Vitamin E requirement is high in thalassaemia. Treating staff should recommend a regular intake of vegetable oils as part of a balanced diet. However, the effectiveness and safety of vitamin E supplementation in thalassaemia major has not been formally assessed and it is not possible to give recommendations about its use at this time.

Zinc Zinc deficiency may occur during chelation, depending on the chelator, dose and duration. Zinc supplementation requires close monitoring.

Alcohol

A transparent discussion of these issues may help the patient to gain insight into the associated risks.

Patients with thalassaemia should be discouraged from consuming alcohol, as it can facilitate

Recreational activities

the oxidative damage of iron and aggravates the effect of HBV and HCV on liver tissue. Where all three factors are present, the probability of developing cirrhosis and

In general, physical activity must always be encouraged in patients with a chronic

Substance abuse

Physical activity

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disease. Patients with thalassaemia should have a quality of life and range of life experiences as much like those of others as possible. There is no reason to prevent patients from engaging in physical activity to the limits of what they are capable of and interested in doing, unless there is a precise secondary medical condition. Conditions requiring special attention include: 単 Splenomegaly: the more enlarged the spleen, the more rigorous treating staff must be in recommending avoidance of those sports and physical activities with significant risk of abdominal trauma. 単 Heart disease: moderate physical activity is beneficial, if is matched to the clinical condition and its treatment. 単 Osteoporosis or back pain in adults may limit physical activity. Osteoporosis carries an increased fracture risk and contact sports should therefore be avoided if osteoporosis is present.

Driving No special attention is needed. In some countries, the presence of diabetes mellitus requires special checks and limitations.

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Organisation and Programming of a Thalassaemia Centre

as possible, in order to provide continuity of care. The staff must include a charge nurse/nurse practitioner who supervises the nursing staff.

The importance of a dedicated thalassaemia unit

The thalassaemia unit should operate on an outpatient basis: facilities for evening, night, and overnight transfusion help minimise inconvenience to the patient’s social life.

Unless the number of patients is minimal, organisation of a thalassaemia unit is useful both in terms of functionality and cost. Attempting to manage many patients with thalassaemia in big multi-purpose units (such as paediatrics, oncohaematology and transfusion centres) without dedicated facilities is often counterproductive, as most resources are used for the main activity of the unit (acute patient, oncology patients, transfusion, etc).

Paediatric vs. adult care The choice between a paediatric or adult medicine setting may be crucial. Paediatric centres, mainly in thalassaemia major, accumulate more experience and are closer to prevention of genetic disease. As treatment opportunities improve, more patients reach adulthood (Figure 1), with a growing number of risk factors and complications. This requires an approach more like that of adult internal medicine.

In a dedicated thalassaemia unit, a treating physician specially trained in thalassaemia oversees all aspects of treatment, referring to specialists when indicated. Staff most commonly involved are: ñ Nurse specialist(s) ñ Cardiologist ñ Endocrinologist ñ Diabetes specialist ñ Reproduction endocrinologist ñ Andrologist or gynaecologist ñ Psychiatrist/psychologist ñ Social worker ñ Hepatologist ñ Transplant specialist

Each patient’s transition from paediatric to adult care must be accurate and smooth: ñ transmission of complete clinical records ñ shared discussion of past and current clinical problems ñ Ideally, a clinician with continued care as patients progress from paediatric to adult stages

Programming of treatment

The unit should be dedicated but not isolated. The staff requires a career structure with promotion possibilities and regular contact with other branches of medicine; otherwise, doctors and nurses can be afraid of losing skills and missing promotion opportunities, and as a result they may be unwilling to work in the unit. It is essential that staff turnover of the unit is kept as low

Transfusion therapy is ideally conducted according to the procedure outlined in Chapter 2: Blood Tranfusion Therapy in ‚Thalassaemia Major. The day of transfusion should be utilised as effectively as possible – ideally providing all treatment and other medical services the patient needs during one visit. This often includes:

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Figure 1: Changing pattern of age distribution in patients with thalassaemia

ñ Physical examination ñ Clinical and laboratory tests, scheduled by the treating physician on the basis of guidelines and individual need. ñ Clinical discussion of the case record ñ Individual conversation to set goals, renew critical information, and listen to the patient (see Chapter 15: Psychological Support in Thalassaemia) ñ Ideally the patient should leave the hospital after every transfusional event with updated documentation.

Interaction of the thalassaemia unit with other hospital facilities The unit must be closely connected with: ñ A blood bank ñ A general laboratory ñ If available, a special laboratory unit, which runs all specific procedures used in the diagnosis, follow-up and monitoring treatment of thalassaemia, ñ The clinical resources of the departments of paediatrics, internal medicine and haematology/oncology critical for thalassaemia (see specialists).

Several programmes for thalassaemia patient data have been set up. Some of them have been computerised and can be distributed to the interested centres upon request (TIF’s website: www.thalassaemia.org.cy).

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Figure 2: An example of organisational interaction of the thalassaemia unit with other hospital facilities [Kattamis 1989]

ñ Updating staff on new aspects of thalassaemia and its treatment ñ Discussing and resolving organisational aspects of the unit’s activities ñ Renewing staff motivation to work in the field of thalassaemia, so as to prevent professional burnout

The well-functioning blood bank is of primary importance for the management of thalassaemia. Its functions are not only to find the huge amount of blood needed for the treatment of thalassaemia, but also to secure the ideal blood for the patient, in order to minimise the risks involved in transfusion (e.g. alloimmunisation and infections). The doctor from the Thalassaemia Unit must keep blood bank staff sensitised to the needs of chronically transfused patients

The organisation of a Thalassaemia Unit

The supervising physician should schedule regular meetings of the staff for the purpose of:

The organisation of the Thalassaemia Unit in this fashion optimises treatment, while

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ñ Capacity for expert diagnosis ñ Expert clinical management ñ The use of outcome measures and quality control, including survival and complication rates, quality of life measures and other measures of patient interest ñ Sufficient activity – which means a minimum number of patients to ensure adequate staff experience for quality care ñ High level expertise and experience of staff ñ Epidemiological surveillance, including patient registers ñ Collaboration with national and international centres ñ Close links with patient associations

ensuring the greatest possible level of comfort and convenience for patients with thalassaemia and their families. It is essential that patients with thalassaemia feel that the unit is their own place, and that the medical staff have the patients’ best interests as top priority. Long-term management implies collaboration of the patient and the family with the well-organised thalassaemia unit team, to ensure continuous, appropriate treatment and a long and productive life for the patient with thalassaemia. A Thalassaemia Unit is expected to be a centre of expertise for the management of a chronic disorder. As such, it should be in a position to provide multidisciplinary knowledge, as described above, with the aim of improving both survival and quality of life. In addition, the centre will provide support to local physicians treating patients with limited access to expert centres, mainly due to distance.

In such a system, the patient is fully supported for self-management and is considered a partner in the decisions affecting his/her treatment, a fact that may assist in patient adherence to long-term treatment protocols.

The European Union has established criteria for such centres of expertise (Rare Disease Task Force Criteria), which could be used as a standard in organising or running an expert or Reference Centre, such as:

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Outline of Diagnostic Dilemmas in Thalassaemia

I - Increased transfusion requirements

VII - Worsening jaundice

A - Hypersplenism B - Alloantibody C - Autoantibody D - Infection with HPV-B19 virus

A - Gilberts B - Increased haemolysis C - Drug Reaction D - Liver failure

II - Fever

VIII - Leg cramps

A - Infection due to Bacterial B - Yersinia C - Klebsiella D - Delayed transfusion reaction

A - Hypocalcaemia B - Hypoparathyroidism

Diagnostic Dilemmas in Thalassaemia

III - Back Pain A - Osteoporosis and microfractures B - Prolapse in disc C - End plate degeneration D - Prolapse

V - Chest Pain

Thalassaemia is an extremely demanding disease. Patients must commit themselves to a lifetime of transfusion and chelation therapy, with all its attendant side effects. At the same time, thalassaemia poses considerable challenges to treating physicians, who often struggle to resolve competing complaints that together pose diagnostic dilemmas. The following chapter addresses some of those dilemmas, including increased transfusion requirements, fever, back pain, abdominal pain, chest pain, dyspnoea, worsening jaundice and leg cramps.

A - Pericarditis and myocarditis B - Rib fracture (extramedullary expansion) C - Pulmonary embolism

I. Increased transfusion requirements

IV - Unexplained Abdominal Pain A - Cholelythiasis B - Pancreatitis C - Portal vein thrombosis D - Renal stones E - Hepatic capsule distension F - Yersinia

VI - Dyspnoea

The recommended treatment for thalassaemia major involves regular blood transfusions, usually administered every two to five weeks, to maintain the pretransfusion haemoglobin level above 9-10.5 g/dl. This transfusion regimen promotes normal growth, allows normal physical activities, adequately suppresses bone marrow activity and minimises transfusional iron accumulation. While shorter intervals between transfusions may reduce overall

A - Dysrhythmia B - Delayed Transfusion reaction G - Pump failure D - Pulmonary hypertension

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anti-Kell alloantibodies are most common. However, 5-10% of patients present with alloantibodies against rare erythrocyte antigens or with warm or cold antibodies of unidentified specificity.

blood requirements, the choice of interval must take into account other factors, such as the patientâ&#x20AC;&#x2122;s work or school schedule. Reasons for increased consumption include hypersplenism, new alloantibodies, infection and changes in the haematocrit of transfused units.

Autoimmune haemolytic anaemia is a very serious complication of transfusion therapy usually combined with underlying alloimmunisation. Even red cells from seemingly compatible units may have markedly shortened survival, and haemoglobin concentration may fall well below the usual pre-transfusion level. Destruction both of the donor red cells and of the recipientâ&#x20AC;&#x2122;s red cells occurs. Steroids, immunosuppressive drugs and intravenous immunoglobulin are used for the clinical management of this situation, although they may give little benefit. Autoimmune haemolytic anaemia may occur more frequently in patients beginning transfusion therapy later in life.

I-A. Hypersplensism Throughout the care of the patient with thalassaemia, the size of the spleen should be carefully monitored on physical examination and, as needed, by ultrasonography. Physicians should be on the look out for hypersplenism with stasis, trapping and destruction of red blood cells in an enlarged spleen. Splenectomy should be considered when annual blood requirements exceed 1.5 times those of splenectomised patients, provided that they are on the same transfusion scheme and have no other reasons for increased consumption. (Reasons for increased blood requirements include new alloantibodies, infection and changes in the haematocrit of transfused units.)

I-C. Autoantibody Autoimmune haemolytic anaemia (AIHA) refers to a collection of disorders characterised by the presence of autoantibodies that bind to the patient's own erythrocytes, leading to the premature destruction of red cells. Specific characteristics of the autoantibodies (especially the type of antibody), its optimal binding temperature, and whether complement is fixed, constitute factors that influence the clinical picture. However, in all cases of AIHA the autoantibody leads to a shortened red blood cell survival (i.e., haemolysis) and, when the rate of haemolysis exceeds the ability of the bone marrow to replace the destroyed red cells, to anaemia and its attendant signs and symptoms.

Enlargement of the spleen is accompanied by symptoms such as left upper quadrant pain or early satiety, or when massive splenomegaly causes concern about possible splenic rupture.

I-B. Alloantibody The development of one or more specific red cell antibodies (alloimmunisation) is a common complication of chronic transfusion therapy. Thus it is important to carefully monitor patients for the development of new antibodies and to eliminate donors with corresponding antigens. Anti-E, anti-C and

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I-D. Infection with HPV-B19

II-B. Yersinia

Parvovirus B 19 - In patients with an already shortened red cell lifespan (15-20 days) and a low haemoglobin level due to haematological disorders such as spherocytosis, sickle-cell anaemia, autoimmune haemolytic anaemia and thalassaemia, B 19 infection may cause an acute, life-threatening red cell aplasia, commonly referred to as â&#x20AC;&#x153;transient aplastic crisisâ&#x20AC;?. The cessation of erythropoiesis lasts for 5-7 days and haematologically complicates chronic haemolytic anaemia. Attention must thus be given not only to aplastic crises, but also to other clinical problems such as myocarditis, which may indicate infection with the virus.

Unlike most other bacteria, Yersinia enterocolitica makes no siderophores of its own and therefore lives most efficiently in an iron-rich environment such as that found in unchelated patients with thalassaemia or uses the DFO in chelating patients which is a siderophore to obtain iron and thrive. The Yersinia organism is most commonly transmitted by the ingestion of contaminated food, meat, milk or water, although it is commensal in healthy individuals. It can also be transmitted through blood. Fever is the most common presenting feature, often associated with abdominal pain and diarrhoea or vomiting. Extra gastrointestinal manifestations, such as arthralgia and skin rashes, are sometimes seen. Complications may include abdominal abscess (right iliac fossa), nephritis or splenic abscess.

II. Fever Fever is an elevation of body temperature that exceeds the normal daily variation. A wide differential exists, spanning all types of infections from bacterial to viral to fungal, along with a multitude of syndromes and organic diseases leading to fever.

Generally antibiotics are continued for at least two weeks after proven infection. Iron chelation should not be restarted until the patient has been asymptomatic for over a week. Relapse after restarting desferrioxamine has been noted in some cases. If this occurs, a longer period of oral antibiotics may be necessary to eradicate the infection. Iron chelation can be recommenced after the infection has been eliminated.

II-A. INFECTION DUE TO BACTERIA In patients with thalassaemia, the causes may include other infections with Klebsiella and Yersinia, or other bacterial pathogens and delayed transfusion reactions. Iron overload and infection are common causes of death. Hence clinical experience mandates that fever and infection, even in the nonsplenectomised patient, be thorough;y investigated and treated swiftly and aggressively. It is recommended that iron chelation be stopped while the cause of unidentified fever is investigated.

II-C. Klebsiella Of the multitude of bacteria described in association with iron overload, Klebsiella species should be addressed as a potential pathogen. In vitro Klebsiella species have been shown to have increased virulence in

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the presence of excess iron. Infection with Klebsiella can be fatal in patients with thalassaemia.

III-A. Osteoporosis There is a high incidence of osteoporosis of the spine and hip in both sexes in thalassaemia, with severity increasing with age. Even young patients exhibit a spinal bone mineral density far below that of agematched controls.

Although there is evidence of altered host immunity in thalassaemia syndromes, only limited information is available regarding the effects or functions of mononuclear phagocytes in relation to micro-organisms and the influence of iron overload and iron chelation on their activity and pathogenicity.

III-B, III-C & III-D. Microfractures, disc prolapse and end plate degeneration

II-D. Delayed transfusion reaction

Patients with thalassaemia may exhibit dramatic skeletal abnormalities, frequently leading to marked changes in the facial structure and body habitus and delayed skeletal maturation. Skeletal changes are due largely to the expansion and invasion of erythroid bone marrow, which widen the marrow spaces, attenuate the cortex and produce osteoporosis.

Delayed transfusion reactions occur 5-10 days after transfusion and are characterised by anaemia, malaise and jaundice. These reactions may be due to an alloantibody that was not detectable at the time of transfusion or to the development of a new antibody. A sample should be sent to the blood bank to look for a new antibody and to recrossmatch the last administered units.

The skull and facial bones are often strikingly abnormal. Marrow expansion causes dramatic widening of the diploic spaces and produces a characteristic ‘hair-on-end’ radiographic appearance of the skull. In addition, there is prominent frontal bossing, delayed pneumatisation of the sinuses and marked overgrowth of the maxillae. As a result, the upper incisors are ‘jumbled’ and the malar eminences are especially prominent, producing malocclusion and the characteristic faces. The ribs and bones of the extremities become box-like and eventually convex, due to expansion of the bone marrow. Premature fusion of the epiphyses can result in characteristic shortening of the limbs, particularly the arms. Of equal concern is the thinning of the cortices due to marrow expansion, which often results in pathologic fractures.

III. Back Pain Back symptoms are the most common cause of disability in patients and account for a huge portion of primary care physician visits. The differential spans congenital anomalies of the lumbar spine (spondylolysis, spondylolisthesis), trauma with sprains and strains, lumbar disk disease and organic causes such as osteoporosis. Patients with thalassaemia experience myriad bone complications. The differential diagnosis includes osteoporosis, microfarctures, disc prolapse and end plate degeneration.

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Compression fractures of the spine, often with spinal cord compression and neurologic deficits, have been reported in children with thalassaemia. Compression fractures and paravertebral expansion of extramedullary masses often become particularly prominent in the second decade of life.

IV-B. Pancreatitis Acute pancreatitis is an inflammatory condition of the pancreas characterised clinically by abdominal pain and elevated levels of pancreatic enzymes in the blood. A number of conditions are known to induce this disorder with varying degrees of certainty. However, the pathogenesis of this disorder is not fully understood.

IV. Unexplained abdominal pain Correctly interpreting abdominal pain constitutes a particular challenge in thalassaemia. The list includes pain originating in the abdomen (peritoneal, mechanical obstruction, vascular, abdominal wall), pain referred from extra abdominal sites (thorax, spine, genitalia), metabolic causes (uremia, porphyria) and neurogenic causes.

Although a number of situations can precipitate acute pancreatitis in humans, only a small fraction of patients with these predisposing factors develop the diseasesâ&#x20AC;&#x201D;3 to 7 percent with gallstone, 10 percent of alcoholics and a few patients with hypercalcemia. With regard to patients with thalassaemia, pancreatitis is caused by myriad factors. First and foremost is increased transfusion requirement, leading to increased turnover of red blood cells and hence further precipitation of gallstones.

Of the multiple complaints patients with thalassaemia present with, unexplained abdominal pain spans a wide differential diagnosis including chloelythiasis, pancreatitis, portal vein thrombosis, hepatic capsule distention and kidney stones.

IV-C. Portal vein thrombosis

IV-A. Cholelithiasis

Venous thrombo-embolism (VTE) is increasingly recognised in paediatrics as a complication of improved treatment strategies for previously lethal childhood diseases. The basic pathological process underlying VTE is Virchow's triad (stasis, endothelial injury and hypercoagulability).

A prominent feature of children with chronic haemolytic anaemia is the development of premature bilirubin gallstone disease and biliary tract inflammation. This is particularly true of children with â&#x20AC;&#x161;-thalassaemia, twothirds of which have multiple calcified bilirubin stones by the age of 15. Fortunately, true episodes of cholecystitis or cholangitis are rare. In the absence of clearcut symptoms, gall bladder removal is thus rarely indicated.

Central venous catheters (CVCs), which present a foreign intravascular surface, damage vessel walls and disrupt blood flow, are responsible for approximately 60 percent of VTEs in children. In patients with thalassaemia, CVCs are resorted to when frequent transfusions are required.

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absence of transfusion, the accelerated rate of iron turnover enhances dietary iron absorption from the gut, resulting in a chronic state of iron overload. In the liver, iron first infiltrates Kupffer cells and then engorges hepatocytes, ultimately provoking fibrosis and, potentially, end-stage liver disease, in a manner analogous to that seen in idiopathic haemochromatosis.

Thrombosis of the hepatic venous system usually occurs within the portal venous system. Older children may develop portal vein thrombosis (PVT) secondary to liver transplantation, infections, splenectomy, sickle cell disease or the presence of antiphospholipid antibodies. PVT may manifest acutely with symptoms of an acute abdomen, particularly in adolescents, or be asymptomatic for long periods of time until symptoms reflecting chronic vascular obstruction (portal hypertension) occur (e.g., splenomegaly or gastrointestinal bleeding secondary to oesophageal varices). In addition, the debris released from intravascular destruction of red blood cells may accumulate and plug the portal vein, particularly after spelenctomy.

V. Chest pain Chest discomfort is one of the most common challenges faced by physicians treating thalassaemia patients. The differential diagnosis includes conditions affecting organs throughout the thorax and abdomen, with prognostic implications that vary from benign to life-threatening. Failure to recognise potentially serious conditions such as acute ischemic heart disease, aortic dissection, tension pneumothorax or pulmonary embolism can lead to serious complications, including death. In thalassaemics, the differential diagnosis spans pericarditis and myocarditis, extramedullary causes and pulmonary embolism.

IV-D. Renal stones The kidneys are frequently enlarged in thalassaemia, due to the presence of extramedullary haematopoiesis. Less well understood is the tendency for the renal tubules to be dilated. The urine is frequently dark, due to increased concentrations of bile pigments; large amounts of urate, uric acid and oxalate are also seen.

V-A. Pericarditis and myocarditis

IV-E. Hepatic capsule distension

Cardiac symptoms and premature death from cardiac causes are still major problems in thalassaemia. Heart complications are the leading causes of death and one of the main causes of morbidity. In the absence of effective iron chelation therapy, many patients develop evidence of iron-induced myocardial damage with cardiac failure, cardiac arrhythmia, sudden death or a distressing slow death from progressive congestive cardiac failure.

Hepatomegaly is prominent early on in thalassaemia, due to increased red cell destruction as well as extramedullary erythropoiesis in the liver. Liver enlargement tends to be somewhat more prominent in children with thalassaemia than in those with congenital haemolytic anaemia. Later in the first decade of life, hepatomegaly becomes fixed and non-reducible by blood transfusion, due to development of cirrhosis secondary to increased iron deposition. Even in the

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pulmonary embolism occurs as part of the full picture of thrombosis. Data indicate that thrombotic events primarily occur in the venous system, comprising deep vein thrombosis (DVT) (40%), portal vein thrombosis (19%), stroke (9%), pulmonary embolism (12%) and others (20%). Moreover, splenectomised patients have been shown to have a higher risk of thrombosis than nonsplenectomised patients. There are several possible reasons for this, including the procoagulant activity of circulating damaged red blood cells, as it is thought that RBC remnants expose negatively charged phosphatidyl-serine through the â&#x20AC;&#x2DC;flip-flopâ&#x20AC;&#x2122; phenomenon and subsequently initiate thrombosis. Deep vein thrombosis, pulmonary thromboembolism and recurrent arterial occlusion have been described in patients with TI, mostly occurring without any other risk factors. It is important to be aware of these complications since thromboembolism plays an important role in cardiac failure.

The regular assessment of cardiac status can identify the early stages of heart disease, enabling prompt intervention. The characteristic lesion in the heart is caused by iron deposition in the myofibres, with associated myofibrillar fragmentation and diminished mitochondrial volume per myocyte. Classically, it has been suggested that there is a poor correlation between myocardial iron content, fibrosis and cardiac functional impairment. Iron distribution in the heart is relatively uneven. It has also been suggested that viral myocarditis is a contributing factor to acute cardiac deterioration.

V-B. Rib fracture (extramedullary expansion) Extramedullary haematopoiesis (EMH) is a compensatory mechanism where bone marrow activity increases in an attempt to overcome the chronic anaemia of thalassaemia intermedia (TI), leading to the formation of erythropoietic tissue masses that primarily affect the spleen, liver and lymph nodes. These masses can be detected by magnetic resonance imaging (MRI). They may cause neurological problems such as spinal cord compression and paraplegia, and intrathoracic masses. Extramedullary haematopoiesis can be managed by radiotherapy, since haematopoietic tissue is highly radiosensitive, as well as transfusion therapy and hydroxyurea.

VI. Dyspnoea A cardinal symptom of diseases affecting the cardiorespiratory system is dyspnoea, defined as an abnormally uncomfortable awareness of breathing. The differential covers general topics of obstructive disease of airways, diffuse parenchymal lung diseases, pulmonary vascular occlusive diseases, diseases of the chest wall or respiratory muscles, and heart diseases. Such an extensive differential necessitates meticulous work up to reach a diagnosis. However, dysrhythmia, pump failure, pulmonary hypertension and delayed transfusion reaction lead the list of probable causes of dyspnoea in thalassaemia.

V-C. Pulmonary embolism Patients with TI have an increased risk of thrombosis compared with a normal age and sex-matched population and with thalassaemia major patients, especially following splenectomy. In TI patients,

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response occurring after re-exposure to a foreign red cell antigen previously encountered by transfusion, transplantation or pregnancy. The antibody, often of the Kidd or Rh system, is undetectable on pretransfusion testing but increases rapidly in titer following the transfusion. These delayed reactions are seen generally within 2 to 10 days after transfusion. Haemolysis is usually extravascular, gradual and less severe than in the case of acute reactions, but rapid haemolysis can occur. A falling hematocrit, slight fever, mild increase in serum unconjugated bilirubin, and spherocytosis on the blood smear may be noted. The diagnosis is often made by the blood bank when ordering more blood for another transfusion, the direct antiglobulin test and antibody screen which were previously negative, now have become positive.

VI-A. Dysrhythmia Significant cardiac disease from iron overload typically occurs in the absence of symptoms. However, when symptoms do occur, they include palpitations, syncopes, shortness of breath, epigastric pain, decreased exercise tolerance and peripheral oedema. The development of symptoms of heart failure implies advanced disease with a poor prognosis. Once the ventricles have enlarged, cardiac arrhythmias are more common. These tend to be of atrial origin, but ventricular tachycardia is also occasionally seen. Sudden death is likely to be arrhythmic in origin and is more likely to be due to ventricular arrhythmia than atrial. The decision to treat arrhythmias in patients with thalassaemia must be carefully considered, bearing in mind that iron toxicity is the primary cause of this complication. Intensive chelation treatment has been demonstrated to reduce arrhythmias. In the majority of instances, the arrhythmias are supraventricular, although ventricular tachycardia may occur in seriously ill individuals. The development of arrhythmia may be associated with a deteriorating ventricular function and can be improved by addressing the latter problem. Arrhythmias require very careful assessment. For most supraventricular arrhythmias, reassurance of the patient is generally appropriate, whereas patients with ventricular arrhythmias should be warned as to the potential severity of their condition.

VI-C. Pump failure The characteristic lesion in the heart is caused by iron deposition in the myofibres, with associated myofibrillar fragmentation and diminished mitochondrial volume per myocyte. Classically, it has been suggested that there is a poor correlation between myocardial iron content, fibrosis and cardiac functional impairment. Iron distribution in the heart is relatively uneven. It has also been suggested that viral myocarditis is a contributing factor to acute cardiac deterioration. An important distinguishing feature of cardiac dysfunction due to iron overload is the capacity of patients, if detected early, to make a complete recovery with appropriate chelation therapy. This fact may not be widely appreciated by physicians and cardiologists unaccustomed to dealing with

VI-B. Delayed transfusion reaction Delayed haemolytic transfusion reactions (DHTRs) are due to an anamnestic antibody

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deposition of bilirubin. Tissue deposition of bilirubin occurs only in the presence of serum hyperbilirubinemia and is a sign of liver disease or, less frequently, a haemolytic disorder. Of the many diseases presenting with icterus, physicians should suspect any of the following: unconjugated hyperbilirubinemia, haemolytic, Crigler-Najjar type II, Gilbert's syndrome, conjugated hyperbilirubinemia, hepatocellular conditions, cholestatic conditions and drugs. Malignant causes should not be missed, including pancreatic, gallbladder, ampullary and cholangiocarcinoma. In patients with thalassaemia, worsening jaundice is another way of presenting to the clinic. Hence the following discussion will shed light on the differential of worsening jaundice in thalassaemics.

patients with thalassaemia. It must be emphasised that supporting the failing circulation in these patients for several weeks may be required in order to achieve recovery.

VI-D. Pulmonary hypertension Pulmonary hypertension (PHT) is prevalent in patients with TI (59.1%), and is thought to be the primary cause of congestive heart failure (CHF) in this patient population. The mechanism underlying PHT in TI is unclear, although evidence indicates a local pathophysiological response in the pulmonary vascular bed that is independent of thromboembolism due to DVT. Suggested mechanisms include endothelial dysfunction with increased inflammation and apoptosis, decreased nitric oxide and nitric oxide synthase production, pulmonary haemosiderosis and local thrombosis. Several echocardiographic studies have confirmed that cardiac ejection fraction is rarely affected in TI. Nevertheless, patients with TI often have an increased cardiac output and left ventricular wall dimensions proportional to the dilutional volume overload secondary to chronic anaemia. As anaemia and iron overload are uncommon in well-transfused and chelated patients with thalassaemia major, they are likely to be at the heart of the pathophysiology of PHT. Regular transfusion and iron chelation therapy is, therefore, indicated in TI patients who are well-stratified according to the early detection of PHT indices. Sildenafil has also been successfully used to treat PHT, although large-scale data for TI patients are lacking.

VII-A. Gilbertâ&#x20AC;&#x2122;s syndrome The most common inherited disorder of bilirubin glucuronidation is Gilbert's syndrome, which has also been called "constitutional hepatic dysfunction" and "familial nonhaemolytic jaundice". Although many patients present as isolated cases, the condition is known to run in families.

VII. Worsening jaundice

Gilbert's syndrome is usually diagnosed in young adults who present with mild, predominantly unconjugated hyperbilirubinemia. It is rarely diagnosed prior to puberty when alterations in sex steroid concentrations affect bilirubin metabolism, leading to increased plasma bilirubin concentrations. The disorder is more commonly diagnosed in males, possibly due to their relatively higher level of daily bilirubin production.

Jaundice, or icterus, is a yellowish discoloration of tissue resulting from the

The physical examination is usually unrevealing, except for icterus. However

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haemolysis even in normal subjects, usually within hours to days after the onset of exposure to the agent. Amyl nitrite and butyl nitrite, primarily via inhalation, have been used to increase sexual arousal. Nitrites bind to haemoglobin, producing methemoglobinemia that may be so profound as to induce coma. The resulting methemoglobinemia and haemolysis may be more pronounced in patients who are G6PD deficient. The possible presence of the latter disorder should be suspected if methylene blue infusion does not quickly turn the chocolate colour of blood back to normal.

situations that exaggerate hyperbilirubinemia may bring the patient to medical attention and have corresponding physical findings. Thalassaemia patients with inherited Gilbert’s syndrome are at increased risk for haemolysis and, as a result, would present with clinical manifestations of icterus and elevated bilirubin.

VII-B. Increased haemolysis Patients with thalassaemia are more susceptible to haemolysis, whether intracorpuscular (intrinsic) or extracorpuscular (a distinction made here because the causes of intrinsic RBC defects are all hereditary). Injury to the RBC membrane due to the production of excess ·- or ‚-globin genes in thalassaemia is an example of an intrinsic defect leading to haemolysis. Extracorpuscular causes of haemolysis, on the other hand, are almost always acquired conditions that lead to the accelerated destruction of otherwise normal RBCs. Examples include antibodies directed against RBC membrane components, such as autoimmune haemolytic anaemia, alloimmune haemolytic anaemia, delayed (haemolytic) transfusion reaction, and some drug-induced haemolytic anaemias. Hypersplenism, which includes stasis, trapping and destruction of RBC in an enlarged spleen, is also part of extracorpuscular haemolysis.

VII-D. Liver failure Hepatitis due to viral (B and C) infections is less frequent in TI than in patients with thalassaemia major, since blood transfusions are much less common in TI. Abnormal liver enzymes (e.g., increased alanine and aspartate aminotransferase) are frequently observed in TI patients, primarily due to hepatocyte damage resulting from iron overload. Normalisation of liver enzyme levels is often observed during appropriate chelation therapy.

VIII. Leg cramps Electrolyte disturbances such as hypocalcemia, endocrine deficiencies and neuromuscular and vascular issues may all result in leg cramps. One-third of patients with thalassaemia major suffer from leg cramps, muscle wasting and weakness. The differential diagnosis includes hypocalcemia and hypoparathyroidism.

VII-C. Drug reactions A variety of drugs have been implicated as causes of drug-induced oxidant haemolysis. Although any defect in the antioxidant defence mechanisms, such as G6PD deficiency, substantially increases susceptibility to haemolysis, the drugs referred to below can produce oxidative

VIII-A. Hypocalcaemia Several acquired causes of hypoparathyroidism have been identified in

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children, including thyroid surgery and iron deposition in the parathyroid gland as a result of frequent transfusions (as in â&#x20AC;&#x161;thalassaemia major).

VIII-B. Hypoparathyroidism In the past two decades, several cases of hypoparathyroidism (HPT) in â&#x20AC;&#x161;-thalassemia major have been observed. HPT is thought to be mainly the consequence of iron deposition in the parathyroid glands. The onset of HPT was preceded or followed in most patients by other endocrine and/or cardiac complications. No clear relationship between HPT and serum ferritin levels was established, suggesting either an individual sensitivity to iron toxicity or early damage of the parathyroid gland before chelation. Furthermore, the fact that no new cases of HPT have been diagnosed at a time when improved chelation therapy regimes have been introduced suggests that chelation may have helped to prevent the development of HPT.

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Index Description

Page Number

A Adefovir Adult Haemoglobin (Hb A) Alendronate Assisted reproduction techniques ART Arrhythmias Alloimmunisation Allergic transfusion reactions Acute haemolytic reactions Autoimmune haemolytic anaemia Arrested puberty Amenorrhoea Acarbose 5 - Azacytidine Alchohol consumption Aplastic crisis Antioxidants Agranulocytosis Arthropathy Anticoagulants ACE inhibitors Amiodarone Abdominal pain

101, 102, 103, 104, 105 14 81 70 84,85, 88, 166 19, 21, 25, 29, 128, 160 22, 30 30 30, 160 60, 65 66 69 136 86, 153 108, 161 39 52, 54, 56, 59 52, 56, 59 49, 88, 117, 129, 126 87, 89 88 58, 112, 114, 159, 163

B Blood donation Bone marrow expansion Back pain Bisphosphonates Butyrates Bumetanide Beta blocking agents

20, 32 16, 79, 162 154, 162 75, 81, 127 129, 137 87 84, 89

C Chimerism Cirrhosis Chelaton Cardiac disease Calcium

133 93, 94, 33, 40, 73, 76, 69, 74,

192

99, 85, 83, 81,

164 128, 144-146, 151, 161 164 127, 152

Circulatory overload (transfusion) Calcitriol Cytotoxic agents Confidentiality Cytomegolovirus (CMV) Chagas disease Chemoprophylaxis

31 69 136 149 111, 132 115 119

D Diabetes mellitus Deferiprone DNA Delayed puberty Desferioxamine DFO DEXA scan Disc prolapse Diet Deferasirox Delayed transfusion reactions Decitabine Dental care Drug abuse Driving Dengue fever Digoxin Diuretics

43, 68, 92, 147 50, 52, 54, 153 12 65, 67 40, 65, 74, 108, 112 74, 79 80, 162 82, 151-153 58, 60, 63 30, 162, 166 136 151 153 154 114 87 87

E Entecavir Extramedullary haemopoiesis Echocardiography Ejection fraction (LVEF) Electrocardiogram (ECG) Erythropoietin (EPO)

101, 105 80, 123, 124, 165 85 38, 51, 73, 85 84 129, 136

F Ferritin Fetal haemoglobin (Hb F) Fractures Fertility Folic acid

35, 41, 50, 57 14, 136 80, 81, 162 70 74, 127, 152

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Filtration (Leukoreduction) Frozen red cells

22, 29 22

G GVHD Growth Growth velocity Glucose tolerance Gene therapy Gallstones (cholelithiasis) Gilbert's syndrome GM CSF

31, 133 45, 64 64 68, 92 139 117, 124, 163 167 52

H HLA Hepatitis C (HCV) Hepatocellular carcinoma Hepatitis B (HBV) HIV Hypersplenism Hypothyrodism Heart failure Haemoglobin E (Hb E) Haemoglobin Lepore Haemoglobin S (Hb S) Haemoglobin H (Hb H) Hb Constant Spring Hb Bart's Hydrops Fetalis Hypogonadic hypogonadism Hormone replacement therapy (HRT) Hydroxyurea Hypoparathyroidism Hypocalcaemia Heart function

31, 133 31, 74, 92-99, 126 93, 99 31, 74, 98-105 31, 74, 109-111 116, 160 67, 97 36, 83, 89, 126, 166 18, 121, 131 18 18 19 19 19 65, 67, 70, 79, 81, 127, 150 74, 77, 81 124, 125, 129, 136 69, 169 69, 169 38, 42, 51, 56, 58, 83

I Iron load (haemosiderosis) Interferon (pegylated) Iron absorption Insulin Insurance (travel)

33-40, 107, 128 95, 97, 101 33, 152 69 151

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Immune function Influenza virus vaccine Indwelling intravenous lines Intensive chelation Immunoprophilaxis

107, 116 118 48 48, 86, 165 118

J Jaundice

167

K Klebsiella

113, 161

L Liver fibrosis Liver failure Liver biopsy Lamivudine Lifestyle Liver iron concentration (LIC) Labile plasma iron (LPI) Leg cramps Leg ulcers

36, 52, 92, 132 93, 168 37, 94, 117 101, 105 149 35, 42, 50, 57, 59, 92, 127 39, 57 168 125, 128

M Matched unrelated donors (MUD) MRI MRI cardiac Malaria Myocarditis

133 37, 80, 124, 92 38, 42, 51, 56, 85 115, 151 38, 84, 164

N Neutropenia Neocytes Nonhaemolytic febrile transfusion reactions Nephrolithiasis (kidney or renal stones) Non transferring bound iron (NTBI)

52, 95 23 29 124, 152, 164 39

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O Osteoporosis Ovulation Oxidative damage

69,74, 77, 79, 127, 154, 162 70, 71 39, 153

P Puberty Pregnancy Pre pregnancy counselling Preimplantation genetic diagnosis (PGD) Pubertal staging Physical activity Parvovirus B19 Palpitations Pericarditis Pancreatitis Portal vein thrombosis Pulmonary embolism Pulmonary hypertension Pseudoxanthoma elasticum Pamidronate

65-67 47, 70-78, 127, 150 70, 73 71 66 153 108, 161 84, 166 164 163 163 165 90, 126, 166 127 81

S Survival SQUID Spermatogenesis Splenectomy Short chain fatty acids School Smoking Splenomegaly Splenic embolisation

43, 135 37 70, 72 29, 107, 116, 124, 128, 160 137 149 153 124, 154 117

T Thrombocytopenia Transfusion requirement Transplantation (Stem cells) Transfusion related acute lung injury (TRALI)

52, 97, 116, 128 23, 28, 29, 97, 116 129, 132-135 31

196

V Vaccinations Vitamin D Vitamin C Vitamin E Vision

98, 99, 101, 118, 151 69, 81, 152 35, 41, 46, 54, 152 153 45, 53

W Washed red cells Work

22 150

Y Yersinia enterocolitica

31, 44, 108, 111-113, 161

Z Zolandronic acid Zinc deficiency

81 53, 64, 65, 153

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About Thalassaemia International Federation The Thalassaemia International Federation (TIF) was established in 1987 with the mission to promote the establishment of national control programmes for the effective prevention and appropriate clinical management of thalassaemia, in every affected country of the world. TIF, a Federation “umbrella”, is comprised of 98 national thalassaemia associations from 60 countries, representing hundreds of thousands of patients worldwide. TIF has been in official relations with the World Health Organisation (WHO) since 1996, and has developed an extensive network of collaboration with scientific and medical professionals from more than 60 countries around the world, as well as with other national and international health bodies, pharmaceutical companies and other disease-orientated patients’ organisations. TIF’s educational programme is one of its most important and successful activities. It includes the organisation of local, national, regional and international workshops, conferences and seminars, and the preparation, publication, translation and free distribution of leaflets, magazines and books for health professionals and patients/parents, to more than 60 countries.

MISSION: “EQUAL ACCESS TO QUALITY HEALTH SERVICES FOR ALL WITH THALASSAEMIA” MOTTO: “UNITY IS OUR STRENGTH”

WORLD HEALTH ORGANIZATION (WHO) RESOLUTION: no. EB118.R1 (29 May 2006) “THALASSAEMIA AND OTHER HAEMOGLOBINOPATHIES”

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“Blood Safety Kit” (1999) In English

“Guidelines to the Clinical Management of Thalassaemia” 2000 Translated into 6 languages

“Compliance to Iron Chelation therapy with Desferrioxamine” 2000 – Reprint 2005 - Translated into 4 languages

“A guide to the establishment and promotion of nongovernment patients/parents’ organization” 2007 - In English

“Guidelines to the Clinical Management of Thalassaemia” Second Edition - 2007 - In English

10.

“Thalassaemia Major and Me” – Children’s Book – 2007 - In English

11.

“About - ‚ - thalassaemia” – 2007 - In English, Italian, French

12.

“About - · - thalassaemia” – 2007 - In English, Italian, French

13.

“About sickle cell disease” – 2007 - In English, Italian, French

14.

Educational Folder Information for the community, the carrier of and the patient with a Haemoglobin disorder.

“About Thalassaemia” 2003 - Translated into 11 languages “Prevention of Thalassaemias and Other Haemoglobinopathies” Volume I (2003) Translated into 2 languages

“Prevention of Thalassaemias and Other Haemoglobiopathies” Volume II (2005) - In English “Patients’ Rights” 2007 - In English

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