Autoimmunity Flashcards Preview

Immunology > Autoimmunity > Flashcards

Flashcards in Autoimmunity Deck (21):

factors contributing to development of autoimmune diseases

immune factors, genetic factors, environmental factors


all autoimmune diseases involve

breakdown of T and B cell tolerance and the production of autoantibody and/or inflammatory autoreactive T cells


breakdown in B cell tolerance

breakdown in: central B cell tolerance, peripheral B cell tolerance


breakdown in central T cell tolerance

defects in AIRE (autoimmunre regulator)


breakdown in peripheral T cell tolerance

insufficient control of T cell costimulation (CTLA-4, B7), lack of regulatory T cells may contribute to autoimmune disease


Th 17

may be link between infection and autoimmunity, helper T cell that secrete IL-17


genetic factors

HLA is the dominant genetic factor affecting susceptibility to autoimmune disease

other factors include AIRE, Fas, FasL, bcl-2, TNF, FoxP3


sympathetic ophthalmia

example of a release of sequestered antigens

trauma to sites of immune privilege - self antigens may be exposed to circulation by wound or infection and effector cells can gain access


celiac disease

example of self proteins may be modified to appear foreign

result is diarrhea, malabsorption of nutrients, IgG or IgA to tissue


molecular mimicry

may contribute to role of infections, pathogen derived peptides structurally similar to a self antigen stimulate a T cell response directed against the self-antigen


hashimoto's disease

infection may lead to increased antigen presentation, upregulation of Class 1 and 2 expression, thyroid gland resembles secondary lymphoid tissue with B and T cells present


additional factors that may contribute to disease mechanisms in genetically susceptible individuals

chemicals, metals, hormones, stress, diet, age


hemolytic anemia

IgG autoantibodies bound to Rh or I antigens may promote antibody dependent cell mediated cytotoxicity (ADCC) or complement fixation.

antibody mediated autoimmune disease (Type 2 hypersensitivity)


Graves disease

autoantibodies bind to the TSH receptor of thyroid cells mimicking the action of TSH so more thyroid hormones are released

can be transferred in utero (to fetus while pregnant)


Myasthenia gravis

anti-acetylcholine receptor antibodies binds to the receptors so muscles cannot contract, leads to muscle weakening


autoimmune diseases that can be transferred in utero

only IgG-mediated diseases (Type 2 and 3 hypersensitivity), T cells cannot cross placenta so no Type 4 hypersensitivity


Systemic Lupus erythematosus (SLE)

type 3 hypersensitivity, immune complex-mediated autoimmune disease, immune complexes contain anti-DNA, anti-nucleosome antibodies, butterfly rash


Juvenile (Type 1) diabetes

type 4 hypersensitivity, beta cells in pancreas produce little or no insulin due to destruction by CD8 cells


Rheumatoid arthritis (RA)

type 4 hypersensitivity, caused by production of antibodies that react with constant regions of other antibodies (rheumatoid factor) and infiltration of joint synovium by inflammatory CD4 and CD8 cells


Multiple sclerosis (MS)

type 4 hypersensitivity, myelin sheath covering cells of spinal cord and brain destroyed due to TH1, macrophages, mast cells, and complement activtation


Treatment for autoimmune diseases

removal of antigen, intravenous IgG, anti-inflammatory drugs, depletion of immune cells, blocking activation of immune cells, replacement therapy, hormones, diet, exercise