3. INTRODUCTION
o The immune system 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 means immunity to self
A condition that occurs when the
immune system mistakenly attacks
and destroys healthy body tissue.
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 concept of 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 causes of 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
o Sequestration 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
13. o Exogenous:
o Molecular mimicry (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
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 HLA TYPES
DISEASE HLA-ANTIGEN
Multiple sclerosis DR3
SLE DR2, DR3
Rheumatoid arthritis DR4
Hashimoto’s Thyroiditis DR5
17. CRITERIA FOR AUTOIMMUNE
DISEASE
o Major:
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 on clinical 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 on laboratory 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
25. EXAMPLES
o SLE (Systemic Lupus 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
27. o Rheumatoid Arthritis:
o Body'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
29. o Multiple Sclerosis:
o Immune 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
31. Crohn’s Disease:
o Immune system 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
33. Myasthenia gravis
o Caused by a problem between nerve ending and muscle fiber.
o Acetyl choline receptors are internalized and degraded.
o Hence impaired muscle contraction.
35. TREATMENT
o Chronic, requiring lifelong 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 Metabolic control - 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 diseases and 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.
