This document provides an overview of autoimmune diseases including causes, types, links to HLA genes, treatment approaches, and mouse models. It discusses three main types of autoimmune diseases: haemolytic, localized, and systemic. Examples like Hashimoto's thyroiditis, myasthenia gravis, multiple sclerosis, type 1 diabetes, systemic lupus erythematosus, and rheumatoid arthritis are explained. The roles of HLA genes and immunosuppressive drugs in treatment are also summarized. Mouse models that replicate human autoimmune conditions are noted.
3. Introduction
โข Autoimmune diseases is a group of disorders
in which tissue injury is caused by humoral (by
auto-antibodies) or cell mediated immune
response (by auto-reactive T cells) to self
antigens.
โข An autoimmune disorder may result in:
โThe destruction of one or more types of
body tissue
โAbnormal growth of an organ
โChanges in organ function
6. 1. Haemolytic autoimmune diseases
โข Clinical disorder due to destructions of blood
components. Auto Ab are formed against oneโs
own RBCs, Platelets or Leucocytes .
โข E.g. Haemolytic anaemia, Leucopenia,
Thrombocytopenia, etc.
7. 2. Localised autoimmune disease
โข A particular organ is affected due to auto Abs.
- For example:
โ Thyroiditis (attacks the thyroid)
โ Multiple sclerosis (attacks myelin coating of
nerve axons)
โ Myasthenia gravis (attacks nerve-muscle
junction)
โ Juvenile diabetes or Type I DM (attacks insulin-
producing cells)
8. Hashimotoโs thyroiditis
โข Hypothyroidism & destruction of thyroid cells.
โข Characterised by Goitre, enlarged thyroid
gland.
โข Characterized by Type IV hypersensitive
reactions.
โข It is a T-cell associated auto immune disease .
9. Myasthenia Gravis
โข Caused by auto antibody against muscle
antigen & acetylcholine receptor antigen.
โข Characterized by โmuscular weakness
โข Eventually death from respiratory failure .
โข Neuromuscular junction is severely affected.
12. Type I diabetes
โข ฮฒ cells produce little or no insulin.
โข Heritable
โข Symptoms are like being very thirsty, hungry,
tired or fatigued, urinating more often.
13. 3. Systemic autoimmune disease
เน Non organ-specific autoimmune diseases
เน Immune complexes accumulate in many tissues
and cause inflammation and damage.
เน For example:
๏ง Systemic Lupus Erythematosus (anti-nuclear
Ab.): Harms kidneys, heart, brain, lungs, skin.
๏ง Rheumatoid Arthritis (anti-IgG antibodies):
Joints, hearts, lungs, nervous system.
๏ง Rheumatic fever: cross-reaction between
antibodies to streptococcus and auto-antibodies.
14. Systemic Lupus Erythematosus (SLE)
โข Skin disease due to the production of
antinuclear factor (ANF) .
โข In these patients, LE cell (a mature
neutrophil) appears in blood & bone
marrow
โFunction โ Phagocytosis in the presence of
ANF.
15.
16. Rheumatoid Arthritis
โข Disease of the joints.
โข Caused by the auto Antibody of IgM type,
called as rheumatoid factors.
โข The synovial fluid of these patients contain
increased no. of T-cells & macrophages.
โข Marked by inflammatory changes in the
synovial membrane.
โข In later stage, deformity develops.
18. HLA & Disease
โข Major histocompatibility complex (MHC) in
humans .
โข This group of genes resides on chromosome 6.
โข HLAs belongs to MHC class I present peptide
from inside the cell which are degraded by
proteasomes.
19. โข HLAs corresponding to MHC class II present
antigens from outside of the cell to T-
lymphocytes.
โข HLAs corresponding to MHC class III encode
components of the complement system.
20. Role of HLA
1. In infectious disease
2. In graft rejection
3. In autoimmunity
4. In cancer
22. Immunosuppresive Drugs
โข Drugs that inhibit or prevent activity
of the immune system.
โข They are used in immunosuppressive
therapy to:
โPrevent
the rejection of transplanted organs
and tissues (e.g., bone
marrow, heart, kidney, liver)
โTreat autoimmune diseases
23. โข Immunosuppressive drugs can be classified into
four groups:
o Glucocorticoids (suppress allergic, inflammatory and
autoimmune disorders) .
o Cytostatics (inhibit cell division) .
o Antibodies (prevent the acute rejection and targeted
treatment of or autoimmune disorders) .
o Drugs acting on immunophilins (Ciclosporin,
Tacrolimus) .
24. Treatment
โข The key to treating autoimmunity is immunomodulation .
โข Some autoimmune diseases are treated with medications
that enhance specific symptoms.
โข Haemolytic anaemia: Treated with Vit B12
โข SLE : Treated with nonsteroidal anti-inflamatory drugs such
as ibuprofen or naproxen, antimalarial drugs, and
corticosteroids.
โ In more aggressive cases, immunosuppressive drugs may
be used.