Immunodeficiencies

1. Immunodeficiencies Martin Liška

2. Basic immunologicalterms Endocrinesystem Immune system provides 3 basic functions: Defense against infection Homeostasis – elimination of old or impaired cells Immunological surveillance - elimination of mutated cells Immunesystem Nervous system Disorders – detectable by laboratory or histological methods, without clinical manifestation Clinical manifestation – decreased function - immunodeficiencies - increased function – allergy, autoimmunity

3. Immunodeficiencies • Humoral – innate immunity - complement, MBL acquired immunity – immunoglobulins (B lymphocytes) • Cell mediated immunity – innate immunity – phagocytes - acquired immunity – T lymphocytes • Primary – congenital, genetically defined, symptoms predominantly at an early age • Secondary – the onset of symptoms at any age chronic diseases the effects of irradiation immunosuppression surgery, injuries stress

4. Immunodeficiencies – critical life periods in respect to symptoms onset • Newborn age - severe primary disorders of cell mediated immunity • 6 mth. – 2 yrs. – severe humoral immunodeficiencies cong./transient • 3 - 5 yrs. – transient and selective humoral immunodeficiencies, secondary immunodeficiencies • 15 – 20 yrs. – hormonal instability, thymus involution, life-style changes, some typical infections first symptoms of CVID • Middleage – often excessive workload, stress first symptoms of autoimmune disorders (also immunodeficiency) • Advanced and old age – rather symptoms of severe secondary immunodeficiencies, repercussion of functional disorders

5. Immunodeficiencies – major clinical features • Antibodies - microbial infections (encapsulated bacterias) respiratory - pneumonia, sinusitis, otitis GIT – diarrhea • Complement – microbial infections (pyogenic), sepsis various systems affection edema (HAE) – C1-INH deficiency • T lymphocytes - bacterial, fungal, viral GIT – diarrhoea respiratory – pneumonia, sinusitis • Phagocytes - abscesses, recurrent purulent skin infections granulomatous inflammations

6. The differentiation of pluripotent stem-cell

7. I. Primary immunodeficiencies – phagocytic cell defects 1/ Quantitative – decreased numbers of granulocytes –neutrophil elastase mutation Congenital chronic agranulocytosis Cyclic agranulocytosis (neutropenia) • Systemic manifestation, fevers in 3-weeks cycles in cyclic form • Treatment with granulocyte growth factors, ATB

8. I. Primary immunodeficiencies – phagocytic cell defects 2/ Qualitative – phagocytes functional disorders, various enzyme deficits, inability of phagocytes to degrade the ingested material Chronic Granulomatous Disease (CGD) • Approximately in 60% X-linked • Enzymatic inability to generate toxic oxygen metabolites (H2O2) during oxygen consumption) - result of defect in neutrophilic cytochrome b (part of complex containing NADPH oxidase) • Inability to kill bacteria such as Staph.aureus, Pseud.aeruginosa that produce the enzyme catalase • Clinical features: granulomas in many organs • Treatment: long-term ATB administration • Myeloperoxidase deficiency • Recurrent microbial infections, susceptibility to Candida albicans and Staph.aureus infections

9. I. Primary immunodeficiencies – phagocytic cell defects Chédiak-Higashi syndrome • Clinical features: recurrent, severe, pyogenic infections (streptococcal, staphylococcal) • Defective intracellular killing of bacteria (neutrophils contain abnormal giant lysosomes LAD syndrome – Leukocyte Adhesion Deficiency (neutrophil adhesion molecules deficiency) • LAD I – integrins expression deficiency • LAD II – selectins expression deficiency

10. II. Primary immunodeficiencies – B cell disorders Bruton’s X-linkedhypogamaglobulinemia • Blockage in the maturation of pre-B lymphocytes into B lymphocytes (tyrosine kinasedefect) • Frequency 1: 50-100 thousands • Undetectable or very low serum levels of Ig • Clinical symptoms in 5-9 mth.of age • Pneumonia, pyogenic otitis,complicated sinusitis,increased occurrence of pulmonary fibrosis • Treatment:life-long IVIGor subcutaneous substitution with Ig CVID – Common Variable ImmunoDeficiency • B cell functional disorder, mostly low levels of IgG and IgA • Frequency 1:100-200 thousands.Symptoms’ onset between 2ndand 3rddecade • Recurrent respiratory tract infections (pneumonia) • Treatment:IVIG substitution

11. II. Primary immunodeficiencies – B cell disorders Selective IgA deficiency • Disorder of B cell function • Frequency 1: 500-700, manifestationmostlyat pre-school age • Recurrent mild/moderate infections (respiratory, GIT, urinary tract) or asymptomatic • Risk of reaction to live attenuated vaccines or generation of anti-IgA antibodies after a blood transfusion • Laboratory criterion: IgA < 0,07g/l (age > 4 years) Selective IgG subclasses or specific IgG deficiency • B cell function disorder • Frequency ? • Onset of symptoms in childhood, mostly respiratory tract infections caused by encapsulated bacteria (H.influenzae, Pneumococci) Transient hypogammaglobulinemia of infancy

12. III. Primary immunodeficiencies –T cell disorders diGeorge syndrome • Disorder of prethymocytes maturation due to absence of thymus • Disorder of development of 3rd and 4th branchial pouch – absence of parathyroid glands • Congenital heart diseases • Frequency 1 : 100 thousands • The onset of symptoms after the birth – hypocalcemic spasms and manifestations of cong.heart disease • Immunodeficiency could be only mild, the numbers of T lymphocytes later usually become normal • Treatment symptomatic HyperIgE (Job’s) syndrome • Most frequently mutation of STAT3 gene (↓ Th17) • Recurrent “cold” staphylococcal abscesses, chronic eczema, otitis media • Extremely high serum IgE levels • Treatment: ATB

13. III. Primary immunodeficiencies – T cell disorders Lymphoproliferative syndrome • Malignant proliferation of activated T lymphocytes • Hypogamaglobulinaemia, lymphoma • Its development is induced by EBV infection Chronic mucocutaneous candidiasis • Impaired ability of T cells to produce macrophage migration inhibiting factor (MIF) in response to Candida antigen Bare lymphocyte sy. • Disorder of antigen presentation – defect of MHC I and/or MHC II expression leads to the dysfunction of CD4 and CD8 lymphocytes IFN-g Receptor deficiency • Th1 lymphocytes differentiation disorder inability of intracellular killing of Mycobacteria (fatal BCG itis)

14. DiGeorge sy MHC I, MHC II def. (bare lymphocyte sy), CD3 def.

15. IV. Primary immunodeficiencies –combined defects of T and B cells • SCID – Severe Combined ImmunoDeficiency • X-linked recessive or AR disease, combined disorder of humoral and cell mediated immunity • Severe disorder (patients often die during first 2 years of life), symptoms’ onset soon after the birth (severe diarrhoea, pneumonia, meningitis, BCGitis) • Immunological features: typically lymphopenia and thymus hypoplasia • Forms: AR form – often enzymatic deficiency (ADA, PNP) that leads to accumulation of metabolites toxic to DNA synthesis (lymphocytes) X-linked form – disorder of stem-cell Treatment: ATB, IVIG BMT is of critical significance in ADA deficiency the gene therapy was tested successfully • Reticular dysgenesis • Stem-cell differentiation is blocked • Very rare • Symptoms immediately after the birth – severe diarrhoea, infections of deep layers • Fatal, BMT is the only treatment

16. SCID Reticular dysgenessis

17. IV. Primary immunodeficiencies – combined defects of T and B cells Ataxia teleangiectasia • Increased radiation induced chromosomal breakage, ataxia, dilatation of small blood vessels (teleangiectasia) • Neurological disorders, immunodeficiency is not necessary (if present, IgA deficiency or T lymphocytes function disorders are most common) • Treatment: ATB, IVIG Hyper IgM syndrome • CD40L expression disorder, poor cooperation of B and T cells, impaired isotype switching, increased IgM levels Wiskott-Aldrich syndrome • thrombocytopenia, eczema, recurrent infections (encapsulated microbes), decreased IgM levels

18. PNP, A-T sy ADA, WAS Adenosin deaminase ADA , Purin nucleosid phosphorylase PNP Wiscott-Aldrich syndrome WAS Ataxia-teleangiectasia sy A-T

19. V. Primary immunodeficiencies –complement system disorders Deficiency of: • C1, C2, C3, C4 – impaired opsonization, susceptibility to infections, autoimunity, SLE–like syndrome • C6, C7, C8, C9 – SLE–like syndrome, increased susceptibility to neisserial infections • MBL deficiency – mannan binding lectin (lectin way of complement activation), various infections, susceptibility to autoimmunity, association with allergy.

20. V. Primary immunodeficiencies –complement system disorders Hereditary angioedema(HAE) • Absence orfunctional deficiency of C1-inhibitor • Skin and/or mucosal (oral, laryngeal, gut) edemascaused by overproduction of bradykinin (regulated by C1-inhibitor) • Injuries or surgical/stomatological operations are mostly the triggering factor • Laryngeal edemas could be life-threatening, immediate treatment is necessary ! • Treatment:preventive – androgens, EACA immediate – C1-INH concentrate or fresh frozen plasma administration, icatibant (selective bradykinin receptor inhibitor) • Secondary form also exists !

21. Secondary immunodeficiencies • Acute and chronic viral infections – infectious mononucleosis, influenza • Metabolic disorders– diabetes mellitus, uremia • Autoimmune diseases– autoantibodies against immunocompetent cells (neutrophils, lymphocytes); autoimmune phenomena also after administrationof certain drugs (e.g. oxacilin, quinidine) • Allergic diseases • ChronicGIT diseases • Malignant diseases(leukemia) • Hypersplenism/asplenia • Burn, postoperative status, injuries • Severe nutritional disorders • Chronic infections • Ionizing radiation • Drug induced immunodeficiencies(chemotherapy) • Immunosupression • Chronic stress • Chronic exposureto harmfulchemical substances

22. Secondary immunodeficiencies • Splenectomy– deficiency in generation of antibodies against encapsulated microorganisms(Pneumococci, Neisseria) • A loss of immunoglobulins – nephrotic syndrome - lymphangiectasies • Lymphomas, myelomas, CLL

23. Secondary immunodeficiencies - A.I.D.S. • Caused by retrovirus HIV 1 or HIV 2 • Current incidence 40 mil.people, predominantly in central Africa, 5mil. of new infections per year, 3 mil.deaths per year • CZ:10/06 - HIV+ 904/248, AIDS 204/14, deaths 23/2 • Virus has a tropism for cells bearing CD4 surface marker(Th CD4+ lymphocytes);also affects macrophagesand CNS cells • Viral genome transcribes into human DNA and infected cell provides viral replication • Transmission: sexual intercourse contact with blood endouterine(mother – fetus, breast milk) • Phases: acute (flu-like sy) asymptomatic – several years, viral replication symptomatic – infections, autoimmunity, malignancy, allergy final –systemic breakdown, opportune infections

24. A.I.D.S. - Treatment • Reverse transcriptase inhibitors (zidovudine, dideoxyinosine, dideoxycytosine, 3-thiacytosine) • Protease inhibitors - block the viral protease enzyme • Combined drug therapy • Antimicrobial agents

25. Substitution therapy with immunoglobulins • Prepared by fractionation of pooled human plasma from huge amount of donors (1000) • Examination of donors, inactivating procedures to minimize the risk of infection transmission • Mainly IgG, minimal content of IgA • i.v. (Octagam, Gammagard) or s.c. use (Subcuvia, Gammanorm)

26. Indications • Primary humoral immunodeficiencies • IgG subclasses deficiencies, deficiencies of generation of specific antibodies, secondary humoral immunodeficiencies, combined immunodeficiencies

27. Dosage • agamaglobulinemia – IVIG 400-600 mg/kg/month • regular substitution in outpatient’s roomevery 3-4 weeks • „home therapy“ (s.c.administration by infusion pump)

28. Adverse effects • Allergic reactions, or even anaphylaxis [in minor reactions (chill, headache) only slowing down of infusion is usually needed]