1. PRESENTED BY
AKSHAYA ANIL
S 3 M.Sc BIOCHEMISTRY
DEPT.OF BIOCHEMISTRY
KERALA UNIVERSITY
ORGAN SPECIFIC
AUTOIMMUNE
DISORDERS
2. AUTO IMMUNITY
The state in which the immune system reacts
against the body’s own normal components, producing
disease or functional changes.
3. AUTOIMMUNE DISEASES
Autoimmune diseases are divided into two classes:
Organ-specific.
Systemic.
Organ-specific disease is one in which an immune response is
directed toward antigens in a single organ or a gland.
Systemic diseases the immune system attacks self antigens in
several organs.
4. ORGAN SPECIFIC AUTOIMMUNE DISEASES
Immune responses is directed towards a target antigen unique
to that organ
Manifestations are largely limited to that organ
Humoral/cell mediated
Antibody may over stimulate/block
5. AUTOIMMUNE DISEASES MEDIATED BY
DIRECTED BY
DIRECT CELLULAR DAMAGE
Lymphocytes or antibodies bind to the cell membrane
antigens
Causes cellular lysis & or inflammatory responses
Gradually the damaged cellular structure is replaced by
connective tissue (fibrosis)
Function of the organ declines
6. 1,HASHIMOTO’S THYROIDITIS
Most frequently found in middle aged women
Individual produces auto antibodies and sensitised T-helper 1 cells specific for thyroid
antigens
Attending delayed type hypersensitivity (DTH) response
Chacterized by an intense infilteration of thyroid gland by lymphocytes,macrophages, &
plasma cells
Forms lymphatic follicles & germinal centres
7. HASHIMOTO’S THYROIDITIS
Ensuing inflammatory response causes goitre, or visible enlargement of the thyroid gland
A physiological response to hypothyroidism
Autoantibodies binds to the proteins including thyroglobulin, & thyroid peroxidase which
are involved in the uptake of iodine
Interferes with the uptake of iodine
10. AUTO IMMUNE ANEMIAS
PERNICIOUS ANEMIA
Pernicious anemia is caused by auto-antibodies to intrinsic factor,a membrane bound
intestinal protein on gatric parietal cells
Intrinsic factor facilitates uptake of vitamin B-12
Vit B 12 is necessary for proper hemotopoesis
Number of functional mature RBC decreases below the normal
Treated with injections of vit B 12,thus circumventing the defect in its absorption
12. AUTO IMMUNE ANEMIAS
AUTOIMMUNE HEMOLYTIC ANEMIA
Makes auto-antibody to RBC antigens
Triggers complement-mediated lysis or antibody mediated opsonization &
phagocytosis of RBC
13. AUTO IMMUNE ANEMIAS
DRUG INDUCED HEMOLYTIC ANEMIA
Drug such as pencillin, or anti hypertensive agent methyldopa interact with RBC
Cells become antigenic
15. 3,GOODPASTURE’S SYNDROME
Auto-antibodies specific for certain basement membrane antigens binds to the
basement membranes of kidney glomeruli & the alveoli of the lungs
Compliment activation leads to direct cellular damage
Ensuing inflammatory response mediated by a buildup of complement splits products
Damage to glomerular & alveolar basement membranes leads to progressive
kidney damage & pulmonary hemorrhage
Death may ensue within several month of the onset of symptoms
18. 4,INSULIN DEPENDENT DIABETES MELLITUS
Disease afflicting 0.2% of the population
Caused by autoimmune attack on pancreas
Attack is directed against specialised insulin-producing ß cells
Located in spherical clusters,called islets of Langerhans
19. INSULIN DEPENDENT DIABETES MELLITUS
Autoimmune attack destroys ß cells
Results in decreased level of insulin
Consequently increased levels of blood glucose
Activated CTLs(cytotoxic T lymphocytes) migrate into islet
begin to attack the insulin producing cells
Local cytokine production during this response includes IFN-gamma,
TNF-alpha, & IL-1
20. INSULIN DEPENDENT DIABETES MELLITUS
CTL infiltration & activation of
macrophages(insulitis)
Cytokinine release & presence of
autoantibody
Cell mediated DTH response
ß cell destruction by DTH
response & lyticenzymes
Autoantibodies
contribute cell
destruction(ADCC)
Autoantibody
production also
contributes in IDDM
21. INSULIN DEPENDENT DIABETES MELLITUS
Destruction of ßcells results in serious metabolic problems that include ketoacidosis
& increased urine production
Later stages are characterised by atherosclerotic vascular lesions
In turn cause gangrene of the extremities due to impeded vacular flow
Renal failure
Blindness
If untreated death
22. INSULIN DEPENDENT DIABETES MELLITUS
Therapy
Daily administration of insulin
Disorder can go undetected for several years,allowing irreparable loss of pancreatic tissue
to occur before treatment begins
Improved techniques for the transplantation for purified islet cells show promise for the
treatment of IDDM
23. AUTOIMMUNE DISEASES MEDIATED BY
STIMULATING OR BLOCKING AUTO-ANTIBODIES
Antibodies act as agonist
Binds to the hormone receptors
Stimulates the inappropriate activity
Usually leads to an over production of mediators or in
increase in cell growth
Conversely auto-antibody may act as antagonist
Binds to hormone receptors
Blocks the receptor function
Impaired secretion of mediators
Gradual atropy of the affected organ
24. 1,GRAVE’S DISEASE
Production of thyroid hormones is regulated by thyroid stimulating hormone(TSH)
Binding of TSH to a receptor on the thyroid cell activates adenylate cyclase
Stimulates the synthesis of thyroxine & triiodothyroninie
In graves disease,autoantibodies that binds the receptor for TSH
Mimic the normal function of TSH
Activates adenylate cyclase
Results in the production of the thyroid hormone
Autoantibodies are not regulated
They overstimulate the thyroid gland
Autoantibodies are called long-acting thyroid – stimulating (LATS) antibodies
27. 2,MYASTHENIA GRAVIS
Prototype autoimmune disease mediated blocking antibody
Autoantibodies binds with the acetylcholine receptors on the motor end plates
of muscles
Blocks the normal binding of acetylcholine
Induce compliment –mediated lysis of the cell
Result in progressive weaking of the skeletal muscles
Ultimately, the autoantibodies causes the destruction of the cell bearing the receptors