04 Immunology

SECTION 4

Immunology 32.

‘Hygiene Hypothesis’ and Development of Immunity Bidyut Kumar Das, Aditya K Panda

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33.

Adult Immunization OP Sharma

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34.

Monoclonal Antibodies: What Clinicians Should Know Anand Sudhakar Bhave

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C H A P T E R

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‘Hygiene Hypothesis’ and Development of Immunity

INTRODUCTION

It is a concept based on the premise that reduced exposure to microorganisms would result in increased immune reactivity promoting allergic and autoimmune disorders.

This has been evident in Western countries where high quality of sanitation has drastically reduced exposure of the population to micro-organisms presumed to have contributed to the ‘silent epidemic’ of autoimmune disorders in first world countries. This premise is supported by epidemiological, experimental and clinical evidence. Incidence of asthma has increased significantly in children in the last 3-4 decades and similarly there is increased prevalence of inflammatory bowel disease (IBD),Type-1 diabetes (T1D), multiple sclerosis (MS) in the past 50 years. Interestingly, such increased incidences of allergy and autoimmune diseases have not been reported in low-income tropical countries where infections are most frequent indicating a possible reciprocal association between infection and allergy/autoimmune diseases which forms the basis of hygiene hypothesis (HH).

EPIDEMIOLOGY

The concept of ‘Hygiene Hypothesis’ (HH) was for the first time introduced by Strachan in 1989 based on the observation of an inverse correlation between sibling size and risk of allergy: more the sibling sizing less was the chance of developing allergic disorders. This was further validated in other studies in different populations.

Furthermore, a meta-analysis of 32 studies revealed decreased risk of atopic dermatitis in infants or children exposed to pet dogs, those consuming less antibiotics and in those who grew up in rural areas.

Besides susceptibility to allergy, the HH is also valid for autoimmune diseases. Interestingly, persons from similar ethnic background living in two different environmental conditions showed six fold higher prevalence of T1D in areas with good sanitary conditions. These observations have been attributed to varied infection rates in two diverse geographical areas: reduced exposure to infection increases autoimmune response to self, facilitating susceptibility to T1D. Prevalence of IBD is higher in US compared to sub Saharan Africa, and increased helminth infection in Africa has been attributed to play a modulatory role in preventing IBD. In India, an inverse correlation between filarial infection and autoimmune disorders such as systemic lupus erythematosus and rheumatoid arthritis has been observed. Interestingly, SLE is more frequent in African Americans compared to West African. Furthermore, human migration studies

Bidyut Kumar Das, Aditya K Panda

have shown that migrants from areas with low incidence of autoimmune disease suffer more from these diseases when they migrate to higher incidence areas.

Allergy and autoimmune diseases result from an exaggerated host immune response against self antigens.

Several factors such as genetic susceptibility, immune dysregulation and environmental triggers have been implicated in the causality of autoimmune diseases.

Genetic factors are unlikely candidates for this surge since mutations associated with disease susceptibility requires a long time span to manifest and the observations on HH are only several decades old. Environmental factors, like parasite infections, play an important role in protection against allergy and autoimmune diseases since they modulate the host immune system for their own survival.

Excessive attention to hygiene and sanitation has resulted in a parasite free environment that has resulted in loss of control over a hyperactive host immune system.

Experimental Evidence

The HH has been subjected to analysis through experimental models and there is robust evidence to support the premise enumerated earlier.

The beneficial nature of infections against different autoimmune disorders through their immunomodulating activity has been demonstrated in animal models. Murine model of colitis induced by trinitrobenzene sulfonic acid (TNBS) or dextran sodium sulfate (DSS) is significantly reduced after exposure to S. mansoni soluble egg antigen through enhancement of IL-4, IL-10 and reduction of IFN-γ . Furthermore, infection of mice with T. spiralis cercariae antigen significantly reduces severity of disease when colitis is induced subsequently.

The administration of helminthic products also showed promising results in experimental autoimmune encephalitis (EAE), a model for MS(multiple sclerosis).

Before the onset of EAE, administration of S. mansoni antigen or its cercariae reduced the severity and incidence of EAE through decreased TNF-α, IL-12, IFN-γ and increased TGF-β,IL-4 and IL-10. In addition, transfer of splenic T-cells from T. spiralis infected rats into experimental model significantly protected them from disease onset.

In collagen induced arthritis (CIA) model, akin to RA, effectiveness of ES-62, a filarial parasite (A. vitae) execretory glycoprotein molecule has been established.

ES-62 interfered with initiation, progression and severity of CIA by diminishing Th-1 and Th-17 immune responses.

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Several experimental evidence indicates protection of nonobese diabetic (NOD) mice from rapid progression to manifest diabetes by infection with S. mansoni cercariae antigens through expansion of TGF-b and increased production of IL-10, IL-4 and IL-13, the anti-inflammatory cytokines.

IMMUNOLOGY

CLINICAL EVIDENCE

Human trials of the effect of parasite products to protect or modulate autoimmune disorders has taken the fancy of the scientific community. Several clinical trials have been carried out to assess safety and effectiveness of helminth therapy. Clinical trials of Trichuris suis (TSO) in CD (Crohn’s disease) and refractory UC(Ulcerative colitis) have revealed significant reduction of disease severity, increased number of responders and enhanced remission rate. However, a recent phase-2 clinical trial in 2013, failed to demonstrate effectiveness of TSO against CD. An important follow-up study comprising of (a) MS patients with naturally infected helminths, (b) MS patients without infections (c) helminths infected subjects and (d) healthy controls. The observation suggested that MS patients who harbored helminth infection had reduced disability scores, lower number of relapse and improved magnetic resonance activity imaging compared to MS patients without helminth infections. Investigation revealed higher levels of IL-10, TGF-b, the anti-inflammatory cytokine, and lower levels of inflammatory cytokines like IFN-γ and IL12 in infected MS patients compared to those without infections.

Although epidemiological data and experimental models suggest a possible therapeutic role for helminths or its products in RA and T1D there are no clinical trials using helminth derived products for therapy in these diseases.

Some robust data from Indian population showed a significant negative association between filarial infection and autoimmune disease such as SLE and RA. Recently, a negative correlation of IL-17 and filarial antigen levels has been postulated as a mechanism of action of filarial worm products in reducing susceptibility to RA and SLE. But it remains to be seen if these observations translate into feasible application.

THE IMMUNOLOGICAL BASIS OF HYGIENE HYPOTHESIS

The immunomodulatory effects of helminth have been extensively investigated. It has several important properties including repression of T-helper -(Th)1/Th17 differentiation, elevation of Th-2 cells , amplification of T regulatory (Treg) and B-reg cells, pivotal in maintaining immune hoemostasis, and change of dendritic cells towards a more tolerogenic subset. Dendritic cells are vital in antigen presentation to T cells.

Naïve T-cells differentiate into Th or Treg cells based on their requirement. T-helper cells further polarize into Th1 and Th2 subsets having distinctly opposite function.

Th1 response has been linked to the pathogenesis of autoimmune diseases cells through production of distinct proinflammatory cytokines. The Th2 response is linked to atopic disorders through increased production of IL4, IL-5, IL-9, Il-10 and IgE. Experimental models infected

with helminths have shown a Th2 type immune response.

Thus helminth infections should leads to atopic disorder in experimental models but it does not translate into disease manifestations. This indicates the importance of other factors such as Th17 and Treg in the final outcome of disease pathogenesis. Infection with helminths down regulate Th1/Th17 mediated inflammatory disorders through increased production and IL-10 and TGF-b. Furthermore, it enhances proliferation of Treg cells that regulates the balance between Th1 and Th2.

Administration of ES-62 helminth product to a collagen induced arthritis model improves disease pathogenesis by suppressing Th1/Th17 cytokines, and increasing Th2/ Treg cytokines (IL-4, IL10). Interestingly, filarial infection in human suppress IL17 production and possibly polarize immune response towards Th2 type.

Helminths promote proliferation of B regulatory cells (Breg) and increase production of IL10. Generation and proliferation of B reg cells by helminth infection have been reported in MS, IBD and CIA model and restoration of IL10 was observed in joints of CIA model Dendritic cells play a pivotal role in the innate immune system and in autoimmune diseases. Important functions of dendritic cells are to capture, process and present antigen to T-cells. DC directs T cells polarization towards immunogenic (Th1, Th17 phenotype) or tolerogenic (Th2, Treg responses). Tolerogenic DC have beneficial role against autoimmune diseases. Polarization of DC towards tolerogenic phenotype has been stimulated by parasite products through toll like receptor or C type lectin receptors.

The other important cell of the innate immune system that drives the adaptive immune response is the macrophage.

Based on external stimuli macrophages undergo classical M1 activation or alternative M2 activation. M2 macrophages are characterized by immunosuppressive and anti-inflammatory phenotype with lower IL12 and higher expression of IL10, TGF-b and arginase-1. In dextran-sodium-sulfate (DSS)-induced colitis mice model, infection with Clonorchis sinensis reduces inflammation by promoting IL10 production from macrophage M2, the non-inflammatory phenotype.

It is apparent that worms, which has co-evolved with the human host over millions of year has a symbiotic relationship. Its survival is depended on evasion of the host immune system through suppression of active immune response that could prevent autoimmunity and allergy as a beneficial spinoff which could be translated into therapeutic application.

CONCLUSION

Hygiene hypothesis has been validated through epidemiological, experimental and clinical observations.

Its impact on several autoimmune diseases and allergic disorders has been critically evaluated with evidence emerging from the role played by helminths and its products in immune modulation. It acts on both the innate and adaptive immune system, down regulating

the inflammatory phenotype. Human clinical trials in the coming decades will provide exciting new parasite molecules for the treatment of autoimmune diseases.

REFERENCES

1.

Panda AK, Das BK. Rheumatoid arthritis patients are free of filarial infection in an area where filariasis is endemic: comment on the article by Pineda et al. Arthritis and Rheumatism 2013; 65:1402-1406.

2.

Panda AK, Das BK. Absence of filarial infection in patients of systemic lupus erythematosus (SLE) in filarial endemic area: a possible protective role. Lupus 2014; 23:1553-1554

Versini M, Jeandel P, Bashi T,Bizzaro G, Blank M, Shoenfeld Y. Unraveling the Hygiene Hypothesis of helminthes and autoimmunity: origins, pathophysiology, and clinical applications. BMC Medicine 2015; 13: DOI: 10.1186/s12916015-0306-7

5.

Maizels RM. Parasitic helminth infections and the control of human allergic and autoimmune disorders. Clinical Microbiology and Infection 2016; 22:481-486

6.

Weinstock JV. Autoimmunity: the worm returns. Nature 2012; 491:183-185

7.

Ben-Ami Shor, Harel M,Ellakim R, Shoenfield Y. The hygiene theory harnessing helminthes and their ova to treat autoimmunity. Clin Rev Allergy Immunol 2013; 45:211216

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3. Panda AK, Das BK. Diminished IL-17A levels may protect filarial infected individuals from development of rheumatoid arthritis and systemic lupus erythematosus.

Lupus 2016; DOI: 10.1177/0961203316662722

4.

Adult Immunization

C H A P T E R

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OP Sharma

The world is greying and so is India. Currently pegged at around 8% of our population, the Indian elderly are projected to constitute around 12.17% of our population by 20261.

As our population ages, infectious disease in this segment is becoming a serious public health concern. The increased risk of infections observed with aging may be due to physiologic changes of ‘homeostenosis’, that accompany “normal” ageing, age-associated diseases and the interventions for them. Immunosenescence contributes to the increased prevalence of infections, cancer and autoimmune disorders in the elderly population with extrinsic and intrinsic causes.

Pneumonia, Influenza, Tetanus & the lately recognized Diphtheria, Pertussis & Herpes Zoster are a group

of Vaccine preventable diseases which otherwise cause considerable morbidity & mortality in older adults. Considering the inadequate medical & health infrastructure; vaccination for above diseases is a good cost effective preventive strategy to achieve positive health.

As one grows old, the immune system undergoes ageassociated changes. The decrease in immune response due to age is termed as immunosenescence. It is characterized by decline in elements of immune response with T and B cells, enhanced pro-inflammatory cytokine production by macrophages, and preservation of the same status of CD8 T cells. This makes the elderly more vulnerable to infections and delayed recovery from infections, it also reduces responses to vaccination.

Table 1: Types of Pneumococcal Vaccine Vaccine

Advantages

Disadvantages

PPSV23

• Long experience (licensed in 1983)

• T cell-independent immune response (IgM antibody produced, response declines in 3—5 years and no anamnestic response at revacc ination)

• Not expensive • At present, relatively high serotype coverage for IPD in elderly (60-70 %) • Considerable efficacy proven against IPD (50—70 %) in immunocompetent elderly • Cost-effective proven for elderly people even if it only prevents IPD

• Decrease in memory B cell frequency after PPV23 • Weak immunogenicity in some individuals • Unclear (null to small) efficacy nonbacteremic pneumococcal

against

• pneumonia. No effect on nasopharyngeal carriage • No efficacy demonstrated nasopharyngeal carriage

in

• No impact proven in reducing pneumococcal disease burden PCV13

• T cell-dependent immune response (larger duration and boosting effect at revacc ination) • High efficacy (80—90 %) against vaccine type IPD proven in children • Significant efficacy against pneumococcal pneumonia (CAPiTA study) • Potential efficacy nasopharyngeal carnage

in

reducing

• Considerable impact in reducing all pneumococcal disease burden shown by prior PCV7

reducing overall

• Short experience (approved in 2011) • Expensive • At present, relatively small serotype coverage for IPD in the elderly (30-40 %) • Future reduction of vaccination impact in adults/elderly (because of probable indirect effects from PCV13 pediatric use)

PNEUMOCOCCAL VACCINE

Pneumococcal disease is an infection caused by streptococcus pneumoniae which manifests as pneumococcal pneumonia, otitis media, sinusitis & IPD (meningitis and bacteraemia).

Annual vaccination against influenza is recommended for any adult who wants to reduce the risk of becoming ill with influenza.

Vaccination is also recommended in : •

persons aged >50 years.

•

women who will be pregnant during the influenza season.

•

persons who have chronic pulmonary infection (including asthma); cardiovascular (except hypertension), renal, hepatic, hematological or metabolic disorders (including diabetes mellitus).

Influenza predisposes patients to pneumococcal pneumonia. Prolonged stay in nursing homes / chronic indoor stay also exposes a person to respiratory infections..

There is increasing incidence of multiple antimicrobial resistances among streptococcus pneumoniae isolates throughout the world. The variation in penicillin resistance in streptococcus pneumoniae across the globe is well known.

•

persons who have immune suppression

•

persons who have any condition (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, or other neuromuscular disorders) that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk for aspiration.

There are two types of vaccines namely pneumococcal polysaccharide vaccine (PPSV23) and pneumococcal conjugate vaccine (PCV13). (Table 1)

•

residents of nursing homes and other chronic-care facilities.

•

health-care personnel.

PPSV 23 is given only once as a single dose to elderly persons. PPSV is a sterile, clear, colourless liquid vaccine. One dose of (0.5 ml) of the vaccine contains 25 micrograms of each capsular polysaccharide antigen dissolved in isotonic saline solution with 0.25% phenol as a preservative. Revaccination may be recommended for persons exhibiting an increased risk for pneumococcal infection

•

house hold contacts and caregivers of children aged <5 years and adults aged >50 years, with particular emphasis on vaccinating contacts of children aged <6 months; and

•

house hold contacts and caregivers of persons with medical conditions that put them at high risk of catching influenza or developing severe complications.

Immunocompromised persons such as those with HIV/ aids exhibit high risk of pneumococcal disease.

PCV13 is administered in a dose of 0.5 ml intramuscularly.

The preferred site is the deltoid muscle of the upper arm.

Tiv is given only once as a single dose to elderly persons.

INFLUENZA VACCINE

Revaccination: influenza vaccine is recommended to be administered annually.

Influenza3 or flu, is an acute, contagious viral respiratory illness, mostly ignored. Infection occurs in the upper respiratory tract; nose, throat, and at times descends to lungs.

Epidemiological survey suggests the presence of influenza virus during all the 12 months of the year with two peak season; one, in and around rainy season and another during the winter months when there is sudden fall in the atmospheric temperature.

There are two types of vaccines: killed and live attenuated vaccine.

The “trivalent inactivated influenza vaccine (tiv) and the live attenuated influenza vaccine (laiv)”, are good and are recommended for use by the advisory committee on immune practice (ACIP) for prevention of influenza.

The seasonal influenza vaccine (laiv) is a trivalent vaccine containing two influenzas a strains: one H1N1 type, one

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TETANUS VACCINE

Tetanus is an acute, often fatal, disease caused by an exotoxin produced by the bacterium clostridium tetani.

It is characterized by generalized rigidity and convulsive spasms of skeletal muscles. The muscle stiffness usually involves the jaw (lockjaw) and neck and then becomes generalized.

In India, however, tetanus is an important endemic infection24.

Vaccine4 available for active immunisation against tetanus is tetanus toxoid, an inactivated tetanus toxin. Tetanus toxoid was first produced in 1924, and tetanus toxoid immunizations were used extensively in the armed services during world war ii.

Vaccine types

Tetanus toxoid consists of a formaldehyde-treated toxin.

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Pneumococcal infections are seen at extremes of age in infants and children, and elderly persons2. Persons with co-existing conditions such as diabetes mellitus, CHF, cardiomyopathy, bronchiectasis, bronchial asthma, COPD, hepatitis C infection, cirrhosis of liver, chronic renal failure are vulnerable to pneumococcal infections.

The smokers too exhibit an increased risk for development of pneumonia.

H3N2 strain and one influenza type b strain (each 15mg) decided by who on the epidemiologic and antigenic analysis of the currently circulating strains.

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The toxoid is standardized for potency in animal tests according to FDA regulations.

Types of toxoid available— •

adsorbed (aluminium salt precipitated) toxoid.

•

fluid toxoid.

IMMUNOLOGY

Although rates of seroconversion are almost about equal, the adsorbed toxoid is preferred because the antitoxin response reaches higher titres and is longer lasting than that following the fluid toxoid.

Tetanus toxoid is available as • a single-antigen preparation - tet-vac (Serum International), sii tetanus toxoid (Serum Institute of India Ltd.), tetanus toxoid (Haffkine institute), tetanus toxoid (Bioe).

-

suspension of tetanus toxoid adsorbed on aluminium phosphate and suspended in isotonic sodium chloride solution

• combined with diphtheria toxoid as paediatric diphtheria-tetanus toxoid (dt) or adult tetanusdiphtheria (td) • with both diphtheria toxoid and acellular pertussis vaccine as dtap or tdap • as combined dtap-hepb-ipv and dtap-ipv/hib

TDAP VACCINE - DIPHTHERIA

Diphtheria 5is a localised infection of mucus membranes of the throat caused by a bacteria called corynebacterium diphtheriae. The infection is potentially fatal and the lethal effect occurs through its toxin. Any person who has not been immunized against diphtheria when exposed to a person infected with diphtheria becomes susceptible to diphtheria.

salt (tdap). After the vaccine has been given, it generally takes about 2 weeks to build immunity in the body28.The adult/adolescent tdap vaccine is recommended as a onetime vaccine to those who have previously completed a schedule of the immunization.

TDAP VACCINE - PERTUSSIS

Pertussis5 or whooping cough or ‘100 days’ cough is a highly contagious infection of the respiratory tract caused by the bacterium, bordetella pertussis.

Infection with pertussis induces temporary natural immunity. Immunization against pertussis does not confer life-long immunity. While adults rarely die if they contact pertussis after the effects of their childhood vaccine get worn off, they may transmit the disease to people at much higher risk of death. The duration of protection by the vaccine is between 5 to 10 years.

New vaccines for use in adolescents and adults, containing small amount of tetanus and diphtheria toxoids with acellular pertussis vaccine have been made available (tdap).

In developed countries, the vaccine that is given to infants aged 6 weeks through 6 years is diphtheria toxoid, acellular pertussis vaccine and tetanus toxoid (dapt). Dt refers to tetanus and diphtheria toxoids without component of pertussis vaccine. Td refers to tetanus toxoid with small amount of diphtheria toxoid. Tdap refers to vaccine given as a one-time vaccine and it contains small amounts of diphtheria toxoid and acellular pertussis vaccine. These vaccines are given as injections in the anterolateral thigh in infants and in the deltoid region for older children and adults. Immunisation against diphtheria and pertussis is necessary to protect adolescents and adults.

Efficacy of the vaccine against clinical disease exceeds 90%.

HERPES ZOSTER

Diphtheria is a vaccine preventable disease. Diphtheria vaccine protects against the disease. A vaccine is recommended as part of routine immunisation in infants in their first year of life and is administered as a combined vaccine with tetanus toxoid and pertussis vaccines (dpt).

Herpes zoster6 is a burden to the public health. Pain and suffering from herpes zoster is greatest for elderly people who are often least able to access medical care or tolerate the medications used to manage the symptoms.

Diphtheria vaccine contains a toxoid (a modified vaccine of the diphtheria toxin) and it is not given as a single injection. It is given in the form of dpt vaccine from six weeks of infancy at monthly intervals three times. dpt vaccine is recommended at the age of 18-24 months to booster its effects. Another booster dose of diphtheria vaccine is recommended at the age of 15-17 years.

Treatment for herpes zoster is not always effective or available. People should start anti-viral treatment within 72 hours of onset of rash in order to get the benefit.

However, many patients do not get diagnosed right away and miss this window of opportunity. Treatment is only partially effective at relieving and shortening the duration of symptoms.

The adolescent/adult dpt vaccine is recommended on a single occasion to those who have previously completed a course of the vaccine.

Shingles is a painful skin rash, often with blisters. It is also called herpes zoster or just zoster. A shingles rash usually appears on one side of the face or body and lasts from 2 to 4 weeks. Its symptoms are severe pain, fever, headache, chills, and stomach upset. For about one person in five, severe pain can continue even after the rash clears up.

This is called post-herpetic neuralgia.

Adults and adolescents receive diphtheria toxoid combined with tetanus toxoid, and pertussis acellular vaccine as a booster. Such vaccine contains a small amount of diphtheria and tetanus toxoid which are modified to make them harmless and small amounts of purified components of pertussis acellular vaccine and aluminium

Shingles is not contagious, and it cannot be passed from one person to another. However, a person who has never

had chickenpox or received chickenpox vaccine could get chickenpox from someone with shingles. Shingles is far more common in people aged 50 and more than in younger people. It is also more common in people whose immune system is weakened from diseases such as cancer, or drugs such as steroids or chemotherapy. a single dose of shingles vaccine is indicated for adults 60 years of age and older.

zostavax, the vaccine to prevent herpes zoster consists of attenuated (oka-strain) varicella virus at a concentration at least 14 times that found in varivax®

•

the vaccine is available as 0.65 ml dose containing a minimum of 19,400 plaque-forming units (ffu) of oka/merck strain of varicella zoster virus.

•

zostavax cannot be used in children and cannot be used in place of varicella vaccine.

•

varivax cannot be used in place of zostavax.

•

the shingles vaccine is specifically designed to protect people against shingles and will not protect people against other forms of herpes, such as genital herpes.

the shingles vaccine is not recommended to treat active shingles or post-herpetic neuralgia (pain after the rash is gone) once it develops.

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In 2011, FDA expanded the age indication for zostavax® to include adults 50 through 59 years old for preventing herpes zoster. For them the risk of getting shingles and having prolonged pain after shingles is much lower than for people 60 years and older.

REFERENCES

1.

Sharma OP, Indian Recommendations for Vaccination in Older Adults – 2015. Pneumococcal Vaccination; 2015, 1127 New Delhi.

2.

Sharma OP. Prevention of disease. Geriatric Care 2004:585591, Viva Books, New Delhi.

3.

Gupte, S. Pediatric Influenza revisited. Asian Pacific J infect Dis 2008; 19:324-332.

4.

Sii Tetanus Toxoid (Adsorbed)(package insert).Serum institute of India ltd, Pune,India;2009. http://www. seruminstitute.com/content/products/product_tetanus_ toxoid.htm

5.

CDC web site: Possible Side Effects of Vaccines and Tetanus, Diphtheria (TD), or Tetanus, Diphtheria, and Pertussis (Tdap) Vaccine. What You Need To Know.

6.

http://www.cdc.gov/vaccines/vpd-vac/shingles/hcpvaccination.htm

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Monoclonal Antibodies: What Clinicians Should Know

INTRODUCTION

It is the duty of the physician to keep abreast of new developments and be in position to offer the most optimal treatment to the patient. Monoclonal antibodies are now becoming available to treat malignant, autoimmune and inflammatory disorders and even some infectious diseases.

HISTORY AND MANUFACTURE OF MONOCLONAL ANTIBODIES

Kohler and Milstein in 1975 devised a technique for which they were awarded the Nobel prize in 1984. They combined the unlimited growth potential of myeloma cells with the antibody specificity of normal B cells. For this they used the following steps:

Anand Sudhakar Bhave Used for rheumatoid arthritis, psoariasis with or without arthritis, ankylosing spondylitis, Crohn’s disease and ulcerative colitis, uveitis and Behcet’s disease.

Typical dosing is 40 mg SC once every two weeks; some conditions need a higher starting dose.

Common side effects include local pain, URTI and sinusitis, rash, headache, elevated CPK.

Vedolizumab

Recombinant humanized antibody, binds to an integrin, inhibits migration of memory T lymphocytes across the endothelium into inflamed gut.

300 mg vial.

Ulcerative colitis and Crohn’s disease.

First, a mouse was immunized by injections of a specific antigen.

300 mg IV at 0, 2, 6 weeks. Maintenance 300 mg every 8 weeks.

Next, splenectomy was carried out and the B cells fused to myeloma cells using polyethylene glycol, yielding fused hybridoma cells.

allergy; incidence 5% overall.

Myeloma cells that have lost the ability to synthesize HGPRT cannot survive in a special medium called HAT (hypoxanthine, aminopterin and thymidine). In this medium the unfused spleen cells die out, myeloma cells cannot survive but the hybridoma cells can survive and grow indefinitely.

Now individual cells from the cell culture can be sub-cultured and the supernatant tested for desired antibodies. This is the most tedious labour intensive part of the process.

Golimumab

Human Anti- TNF-α, blocks inflammatory activity.

50 & 100 mg/ml.

Used for RA and psoariatic arthritis, ankylosing spondylitis, ulcerative colitis.

Usual dose 50 mg / month SC. Infections, rash, leukopenia, immune reactions in the skin and lungs.

Infliximab

Recombinant humanized Anti TNF-α action.

Selected cultures can be grown indefinitely in vitro or in mice, to yield desired antibodies.

100 mg/ vial.

Mouse antibodies are seen as foreign antigens by patients’ immune system, and antibodies can be produced against them. To reduce this problem, chimeric antibodies can be produced that are part human; or humanized antibodies; using recombinant technology. These can be grown in mammalian cell cultures.Transgenic mice may be used in the future for production of monoclonal antibodies.

Dose 5 mg/kg IV at 0, 2, 6 weeks and every 6 weeks afterwards.

Applications of monoclonal antibodies are increasing every day. A partial list follows:

Human Neutralizes interleukin -17A.

AUTOIMMMUNE DISEASES

Adalimumab

Recombinant Human Anti-TNF-α antibody. Blocks the binding of TNF-α to cells, destroys cells which have this inflammatory mediator bound to the surface, hence reduces inflammation.

Available as 40 mg/ 0.8 ml prefilled syringe.

Used for RA, AS, psoariasis with / without arthritis.

Increased risk of infections, including TB, invasive fungi, legionella, listeria, viruses.

Lymphomas have been reported.

Secukinumab

Available as 150 mg vial.

Used for treatment of psoariasis and ankylosing spondylitis.

Dose 300 mg/ weekly SC for 5 weeks then 300 mg/ month.

As many as 30% patients may develop infections during the treatment. TB must be ruled out beforehand. Live vaccines cannot be given during treatment.

Alefacept

Natalizumab

Available as vials of 7.5 and 15 mg.

300 mg/15 ml.

Used to treat psoariasis.

Multiple sclerosis; Crohnâ&#x20AC;&#x2122;s disease.

Dosing is 15mg/ week IM for 12 weeks.

300 mg IV over 1 hr, every month.

Local reactions and lymphopenia may occur.

Risk of PML, IRIS in patients of PML, allergy, HSV/VZV encephalitis, hepatic injury can occur.

A recombinant dimeric fusion protein that inhibits T cell activation.

Ustekinumab

Human; antagonizes IL-12 and IL-23.

Recombinant human, binds to integrin subunits, prevents leukocyte-endothelial adhesion

MULTIPLE APPLICATIONS

Psoariasis with or without arthritis. Under study for type 1 DM with preserved beta cell function and for biliary cirrhosis.

10 mg/ml.

Humanized, anti CD-20, cytolytic.

NHL, CLL, RA, Wegener granulomatosis, microscopic polyangiitis, ITP, pemphigus vulgaris.

Usual dose 375 mg/m2 IV then maintenance.

Usual dose 45 mg SC, then repeat at 4 weeks and every 12 weeks later.

Fatal infusion reactions can occur. Mucocutaneous reactions, PML, hepatitis B reactivation, arrhythmia, tumour lysis can occur.

TRANSPLANT REJECTION

MALIGNANT DISEASES

Basiliximab

Interleukin-2 receptor antagonist.

10/ 20 mg IV injections are available.

Used along with steroids and cyclosporine in renal transplant for preventing rejection.

INFECTIOUS DISEASES

Bezlotoxumab

Fully human; Binds C. Difficile toxin and neutralizes it, does not allow binding to human colonic cells.

FDA approval pending.

Ofatumumab

Human, anti CD-20, inhibits B cell activation.

100 mg/ 5 ml and 1000 mg/ 50 ml vials.

Used for CLL. Allergy, Hep B activation, PML can occur.

Ibritumomab tiuxetan, obinutuzumab

Both these are also anti-CD 20 antibodies for use in CLL.

Alemtuzumab

Recombinant, anti CD-52, causes lymphocyte lysis.

Raxibacumab

CLL, multiple sclerosis. Can be used for kidney transplant rejection.

IV formulation 50 mg/ml.

Bevacizumab

Recombinant human; against bacillus Anthracis.

Treatment of inhalational Anthrax.

Recombinant humanized, blocks angiogenic molecule VGEF.

40 mg/kg IV single dose over 2.5 hrs.

25 mg/ ml.

Requires dose of diphenhydramine as premedication.

Metastatic colorectal cancer, non- small cell lung cancer, breast cancer, renal cell cancer, cervical, ovarian, fallopian tube cancer.

Zmapp

Combination of 3 monoclonal antibodies against Ebola virus surface glycoprotein GP. Was used in the recent Ebola epidemic in Africa.

GI perforation, wound dehiscence, thrombosis are possible side effects.

hemorrhage,

NEUROLOGY

Brentuximab

Humanized; Binds IL-2 receptor subunits, which are expressed on T cells. So inhibits abnormally activated T cells in multiple sclerosis.

50 mg/ vial.

150 mg/ ml in a single dose prefilled syringe.

For multiple sclerosis.

PML, pulmonary toxicity, neuropathy, SJS, anaphylaxis, hepatic failure, GI perforation.

150 mg SC once a month.

Denosumab

Daclizumab

Need to rule out existing and developing autoimmune hepatic damage or tuberculosis. Live vaccine contraindicated during therapy. Immune mediated skin disease.

CD-30 directed antibody-drug conjugate.

Hodgkinâ&#x20AC;&#x2122;s lymphoma, anaplastic large cell lymphoma.

1.8 mg/kg IV every 3 weeks.

Binds to RANKL and inhibits its binding to RANKL receptors, thus inhibits osteoclast formation.

60 or 70 mg/ml vials.

CHAPTER 34

90 mg/ml; SC injection.

Rituximab

Hypersensitivity reactions, severe infections and development of malignancy are possible major adverse effects, apart from minor reactions.

153

154

Hypercalcemia of malignancy, prevention of fractures in patients with bone metastases, osteoporosis, giant cell tumor.

Allergy, hypocalcemia, serious infections need to be watched for. Osteonecrosis of jaw may occur. Bone pain, pancreatitis reported.

Malignant melanoma.

3 mg/kg IV every 3 weeks. Max 4 doses.

Immune reactions in any organ.

Pembrolizumab

Anti- programmed cell death- 1 protein(PD- 1)

60 mg SC once a month.

IMMUNOLOGY

50 mg/ 10 ml, 200 mg/ 40 ml.

Cetuximab

50 mg/ vial.

Recombinant humanized, binds EGF receptors.

Melanoma, non small cell lung cancer.

2 mg/ml.

2 mg/kg IV every 3 weeks.

Colorectal and head and neck cancer.

Anaphylactic reactions and immune reactions in various organs.

Infusion reactions, reactions.

cardiac

arrest,

muco-cutaneous

400 mg/m IV then maintenance.

2

Panitumumab works by same mechanism as above.

Nivolumab works by same mechanism as above.

HEMATOLOGY

Eculizumab

Daratumumab

Blocks complement protein C5.

Anti CD-38, expressed on myeloma cells.

10 mg/ml.

100 mg/5 ml, 400 mg/ 20 ml.

In atypical HUS, inhibits complement mediated thrombotic microangiopathy. Reduces hemolysis in PNH.

Multiple myeloma, diffuse large B cell lymphoma.

Infusion reactions in 50%.

Dinutuximab

Chimeric anti-gd-2.

17.5 mg/ ml.

Pediatric neuroblastoma.

Infusion reactions, neuropathy, marrow suppression, infection.

Dinutuximab works by same mechanism.

Elotuzumab

Humanized, targets SLAMF7; activates natural killer cells to destroy myeloma cells 300 mg/vial.

Used with dexamethasone and linelidomide in myeloma therapy.

Trastuzumab

Anti HER-2.

440 mg/vial.

Breast, gastric, pancreatic cancer.

4 mg/kg IV then weekly 2 mg/kg.

Cardiac failure, infusion reactions, pulmonary toxicity, fetal toxicity.

Pertuzumab also works by same mechanism.

Siltuximab

Binds IL-6.

100 mg/ vial.

Castlemanâ&#x20AC;&#x2122;s disease.

1 mg/kg IV every 3 weeks.

Anaphylaxis, infections, teratogenicity, GI perforation.

Ipilimumab

T cell antibody.

Being studied for myasthenia, neuromyelitis optica and dermatomyositis. Minor reactions common, increased risk of meningococcal infection.

CARDIOVASCULAR

Evolocumab

Antibody to PCSK9.

420 mg every 4 weeks.

Hypercholesterolemia.

Abciximab

Antiplatelet GpIIb/IIIa inhibitor.

Supplied as 2 mg/ml; given 0.25 mg/kg bolus before PCI, then infusion.

For PCI, NSTEMI, STEMI. Bleeding, hypotension, nausea, allergy.

It is mind-boggling to imagine what novel applications will emerge for this technology in the future.

REFERENCES

1.

Lamberg L. A host of novel agents for treating psoariasis, psoariatic arthritis stir interest. JAMA 2003; 289:2779 2. Aaltonen KJ, Virkki LM, Malmivaara A, Systematic review and meta -analysis of the efficacy and safety of existing TNF blocking agents in treatment of rheumatoid arthritis.

PLoS one 2012; 7:e30275.

3. Donahue KE, Gartlehner G, Jonas DE; Systematic review: comparative effectiveness and harms of disease-modifying medications for rheumatoid arthritis. Ann Internal Med 2008; 148:124 4. Ramiro S, Smolen JS, Landewe R; Pharmacological treatment of psoariatic arthritis. Ann Rheum Dis 2016; 75:490.

5. Raal FJ, Honarpour N, Blom DJ, Inhibition of PCSK9 with evolocumab. Lancet 2015; 385:341.

6. Vinay DS, Ryan EP, Pawlelec G; immune evasion in cancer; Mechanistic basis and therapeutic strategies. Semin Cancer Biol 2015; 35 suppl; S 185.