Test 2: Autoimmunity Flashcards
T/F: There are rising incidence of autoimmune and inflammatory diseases in industrialized countries
True!
- unsure why
Antibody mediated autoimmune diseases can be caused by ___________.
Type II and III hypersensitivity reactions
(type I does not cause autoimmune diseases)
T cell mediated autoimmune diseases are caused by _______.
Type IV hypersensitivity reactions
In type II autoimmune diseases, what is one reaction?
opsonization and phagocytosis/complemet mediated lysis mechanisms which are directed against cell-associated self-antigens)
ex: autoimmune hemoltyic anemia= anti-RBC antibodies probably with and Rh or I antigens
PHAGOCYTOSIS
In type II autoimmune diseases, what is another reaction?
complement and Fc receptor mediated mechanism which are directed against tissue self-antigens
- not direct cell destruction but does cause inflammation
ex: pemphigus vulgaris= antibodies in desmosomes in epidermis probably with desmosome antigens
INFLAMMATION AND TISSUE INJURY
In type II autoimmune diseases, what is another reaction?
autoantibody mediated alteration of physiological responses which are directed against receptors
- not just inflammation
ex: graves disease= anti-thyroid stimulating hormone receptor which act as an agonists to overproduce thyroid hormone with thyroid stimulating hormone receptor antigen
ex: myasthenia gravis= anti-acetylcholine act as antagonists to block acetylcholine and inhibit muscle activation with acetylcholine receptor antigen
ANTIBODIES INHIBIT BINDING OF NEUROTRANSMITTER TO RECEPTOR
In type III autoimmune diseases, what is one reaction?
immune complex deposition
ex: systemic lupus erythematosus= auto antibodies against a wide variety of cellular components and form complexes in small blood vessels with nucleic acids, histone, and ribosome antigens
In type IV autoimmune diseases, what is one reaction?
cytokine-mediated inflammation
ex: Hashimoto’s thyroiditis= damage to thyroid resulting in hypothyroidism due to anti-thyroid autoantibodies and decrease in thyroid hormone production with thyroglobulin and thyroid peroxidase antigens
CD4 T cell response
In type IV autoimmune diseases, what is another reaction?
cytokine-mediated inflammation & T cell-mediated cytotoxicity
ex: Insulin-dependent Diabetes Mellitus (type I= destruction of pancreatic beta cells due to anti-pancreatic T cells and results in decreased production of insulin and increase glucose with insulin, GAD-65 antigens
ex: Multiple Sclerosis= lesions in myelin sheath giving demyelination due to anti-myelin T cell cells with myelin basic protein being an antigen
T/F: Most autoimmune diseases require genetic and environmental factors
True!
- it is very complex and requires multiple hits for most autoimmune diseases. monozygotic twins more likely for autoimmune diseases than dizygotic to prove this
T/F: there is an association of autoimmune diseases with alleles of major histocompatibility complex
True!
T/F: Non-MHC factors have a strong association with autoimmune diseases
False!
They do have a weak association but MHC factors are much stronger
Why are females at greater risk or developing most autoimmune diseases?
Hormones!
- female sex steroid (estrogen) tend to be immunoenhancive and male sex steroids (androgens) tend to be immunosuppressive
How is release of sequestered antigens induced?
trauma-induced
ex: sympathetic ophthalmia
- must have genetic predisposition but activated with trauma
How does molecular mimicry work?
cross reaction between pathogen antigen and self-antigen
ex: rheumatic fever
