Week 9 - Autoimmunity Flashcards
Define autoimmunity.
Immune response against self (auto-) antigen
What are the 4 general principles of autoimmunity?
Pathogenesis: the development of autoimmunity reflects a combination of susceptibility genes and environmental triggers (usually infections)
Different autoimmune diseases may be systemic or organ-specific; may be caused by different types of immune reactions
Vary by age, gender and race.
Financial burden
What is the etiology of autoimmune diseases?
Genetic predispositions, endocrine effects, and environmental factors work together
What are the 5 environmental factors of autoimmunity?
Microorganisms
Xenobiotics
Apoptosis
Microbiota
Nutrition
What 2 environmental factors form “molecular mimicry”? Give four examples of each factor
Microorganisms: bacteria, viruses, parasites, fungi
Xenobiotics: tobacco smoke, ultraviolet light, pharmaceuticals, and heavy metals
What 1 environmental factor leads to autoantigens?
Apoptosis
Give examples of microbiota and nutrition.
Microbiota: skin, respiratory mucosal barrier, and GI tract
Nutrition: gluten, iodine, and vitamin D
How do molecular mimicry and auto antigens work together? What types of autoimmune diseases do they cause?
They both lead to auto reactive T or B cells or APCs which are linked to epitope spreading and also causes auto reactive T or B cells
Mimicry/auto antigens directly leading to auto reactive T or B cells lead to organ specific autoimmune diseases
The APC to epitope spreading to auto reactive T or B cell lead to systemic autoimmune diseases
What are 3 details about organ-specific autoimmune diseases?
Autoimmune attack vs. self-antigens of given organ
It results in a damage of organ structure and function
Treatment is focused on the replacement of organ function
What are 3 details of non organ-specific (systemic) autoimmune diseases? (In general)
Widespread self-antigens are targets for autoimmune attack
Damage affects such structures as blood vessels, cell nuclei, etc.
Treatment is aimed to inhibit excessive activation of the immune system
Give examples of organ-specific and non-organ-specific autoimmune diseases and the body parts they affect.
Organ specific:
Brain: multiple sclerosis
Thyroid: Hashimoto’s thyroiditis, primary myxoedema, thyrotoxicosis
Stomach: pernicious anaemia
Adrenal: Addison’s disease
Pancreas: insulin-dependent diabetes mellitus
Non-organ-specific:
Muscle: dermatomyositis
Kidney: SLE
Skin: scleroderma, SLE
Joints: rheumatoid arthiritis
Give 4 details about organ specific auto-immune diseases.
Multiple sclerosis: disease where the immune system attacks the protective coating around the nerves
Hashimoto’s thyroiditis: autoantibodies against many thyroid proteins
Pernicious anemia: non-absorption of vitamin B12 which is essential for red blood cell development
Type 1 diabetes: cytotoxic T-lymphocytes destroy insulin-producing Beta-cells in pancreas
What are 3 details about non-organ specific auto-immune diseases?
Dermatomyositis: muscle disease that is characterized by inflammation and a skin rash; type of inflammatory myopathy
Lupus: disease that damages the joints, skin, kidneys, heart, lungs and other parts of the body; most prevalent autoimmune disease in developed countries; individuals develop antibodies to the DNA of the double-stranded molecules
Rheumatoid arthritis: Ag-Ab complexes deposited in joints and lead to inflammation
What are 4 details about the diagnosis of autoimmune diseases?
Based on symptoms and detection of antibodies
Antibodies against cell/tissue associated antigens are detected by immunofluorescence
Antibodies against soluble antigens are normally detected ELISA or radioimmunoassay
Biological and biochemical assay also used
What are 4 preventions and treatments of autoimmune diseases?
Immunosuppression (e.g., prednisone, cyclosporine A)
Removal of thymus
Plasmapheresis (remove Ab-Ag complexes)
Block MHC with similar peptide
