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Autoimmunity.ppt
- 1. AUTOIMMUNITY Dr Shrutikirti Gupta Mbbsmd microbiology Consultant microbiologist KEM MUMBAI
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- 3. INTRODUCTION o The immunesystem normally works to defend the body and eliminate infections caused by bacteria, viruses, and other invading microbes and don't react with self antigens. o If a person’s immune system mistakenly attacks self, targeting the cells, tissues, and organs of own body, it results in autoimmunity that may manifest as an autoimmune disease. o There are more than 80 different kinds of diseases caused by autoimmunity.
- 4. Autoimmunity Basically meansimmunity to self A condition that occurs when the immune system mistakenly attacks and destroys healthy body tissue.
- 5. The “Immunology Definition” Failureof immune tolerance
- 6. Autoimmunity Origins Horror autotoxicus:Literally, the horror of self-toxicity. A term coined by the German immunologist Paul Ehrlich (1854-1915) to describe the body's innate aversion to immunological self- destruction.
- 7. History Continued This conceptof autoimmunity as the cause of human illness is relatively new, and it was not accepted into the mainstream of medical thinking until the 1950s and 1960s.
- 8. Causes o Exact causesof all autoimmune diseases not known o Not contagious. o Some autoimmune diseases are familial. o The genes people inherit contribute to their susceptibility for developing an autoimmune disease. o The diseases may show up as different illnesses in different family members.
- 9. Mechanisms of Autoimmunity oSequestration of self antigen-Hidden antigens o Tolerance (central deletion , peripheral anergy) o Loss of Regulatory mechanisms o Shared/Cross reacting antigens o Genetic abnormalities-Defects in IR genes
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- 13. o Exogenous: o Molecularmimicry (RF) o Super antigenic stimulation (Staphylococcal protean A) o Microbial adjuvanticity o Endogenous: o Loss of immunologic privilege (MS, Sympathetic Ophthalmia) o Presentation of novel/cryptic epitopes o Altered self antigens (inflammation, drugs, senescence - chemical alteration in proteins o Enhanced function of antigen presenting cells o Cytokine imbalance o Gene (MHC alleles-DM,RA, SLE) o Sex F>M MECHANISMS OF AUTOIMMUNITY
- 14. PROPOSED MECHANISM BYWHICH AUTOIMMUNE RESPONSES ARE INDUCED
- 15. CLASSIFICATION o Hemocytolytic diseases: o Autoimmune hemolytic anemia o Autoimmune thrombocytopenia o Localized (organ specific): o Myasthenia gravis o Eye - auto antibodies against eye lenses o Systemic (non organ specific): o SLE o Rheumatoid Arthritis o Sjogren’s syndrome,PAN, o Transitory diseases: o Anemia, thrombocytopenia following certain infections or drug therapy
- 16. ASSOCIATION WITH HLATYPES DISEASE HLA-ANTIGEN Multiple sclerosis DR3 SLE DR2, DR3 Rheumatoid arthritis DR4 Hashimoto’s Thyroiditis DR5
- 17. CRITERIA FOR AUTOIMMUNE DISEASE oMajor: o Presence of auto antibodies/cellular reactivity to self o Document the relevant antibody in the pathologic lesion o Demonstrate that the antibody can cause tissue pathology o Minor: o Reasonable animal model o Beneficial effect from Immuno -suppressive drugs o Associated with other autoimmune diseases o No effect of infection or other obvious causes
- 18. DIAGNOSIS o Based onclinical examination: o Strike any part of the body, symptoms vary widely and diagnosis and treatment are often difficult o Based on an individual's symptoms, findings from a physical examination, and results from laboratory tests o Difficult to diagnose, particularly early in the course of the disease o Symptoms of many autoimmune diseases are nonspecific o Although autoimmune diseases are chronic, the course they take is unpredictable
- 19. DIAGNOSIS o Based onlaboratory results: o Elevated serum gamma globulins o Depressed complement levels o Presence of immune complexes in serum o Depressed number of T suppressor cells o Presence of Auto antibodies o Presence of anti-DNA antibodies
- 20. Pick an organ,any organ . . . Autoimmunity can affect ANY organ/organ system in the human body Pemphigus Multiple Sclerosis Sjogren’s Syndrome Rheumatic Fever Autoimmune Hepatitis Ulcerative Colitis Goodpasture’s Syndrome Diabetes Autoimmune Uveitis Autoimmune hemolytic Anemia Addison’s Disease Rheumatoid Arthritis Autoimmune Oophoritis
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- 23. Examples of OrganSpecific Lungs of a patient with Goodpasture’s Vitiligo Hashimoto’s disease (thyroiditis)
- 24. Examples of SystemicAutoimmunity Sjogren’s Syndrome
- 25. EXAMPLES o SLE (SystemicLupus Erythematosus): o Profound fatigue, rashes and joint pains o Immune system may attack and damage several organs such as the kidney, brain, or lung o Symptoms and damage from the disease can be controlled with available anti-inflammatory medications o If a patient is not closely monitored, the side effects from the medications can be quite serious
- 26. SLE (Systemic LupusErythematosus)
- 27. o Rheumatoid Arthritis: oBody's immune system attacks the tissues of the joints o Erosion of the menisci causes severe joint pain and immobility o HLA DR4 o Rheumatoid factor present
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- 29. o Multiple Sclerosis: oImmune system targets nerve tissues of the central nervous system o Patches of myelin sheath are destroyed o Affected nerve fibers, which then cannot conduct nerve impulses properly o Most common disabling disease of the nervous system in young adults
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- 31. Crohn’s Disease: o Immunesystem attacks the gut (intestine) o Causes inflammation, thickening and ulceration of the intestinal tract o Symptoms include abdominal pain, diarrhoea and the malabsorption of food, leading to weight loss o Treatment includes rest, changes to the diet and antibiotic and steroid drugs
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- 33. Myasthenia gravis o Causedby a problem between nerve ending and muscle fiber. o Acetyl choline receptors are internalized and degraded. o Hence impaired muscle contraction.
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- 35. TREATMENT o Chronic, requiringlifelong care and monitoring, even when the person may look or feel well. o Currently, few autoimmune diseases can be cured or made to "disappear" with treatment. o A limited number of immuno- suppressive medications may result in disease remission. o Immuno suppressive medications suppress the ability of the immune system to fight infection and have other side effects. o Medical science is striving to design therapies that prevent autoimmune diseases.
- 36. TREATMENT MODALITIES o Metaboliccontrol - Graves’ disease. o Anti-inflammatory drugs - Symptomatic treatment. o Splenectomy - ITP, Hemolytic disease. o Plasmapheresis - SLE,GB Syndrome. o Thymectomy - Myasthenia gravis.. o Anticholinesterases - Myasthenia gravis
- 37. SUMMARY o Autoimmune diseasesand conditions exist when the body produces abnormal cells, which attack the body, itself. o Most autoimmune diseases strike women more often than men. o The causes of autoimmune diseases are not known but some autoimmune diseases seem to run in families. o Strike any part of the body, symptoms vary widely and diagnosis and treatment are often difficult. o Medical science is striving to design therapies that prevent autoimmune diseases.