Autoimmune Diseases

what is autoimmunity

specific immune response to self antigens

autoimmunity can be

organ specific

localized

systemic

most autoimmune disease are characterized by

cyclic periods of alternating clinical diseases and convalescence

what are the ways to diagnose a autoimmune disease

direct proof

indirect proof

isolating self-reactive antibodies or T lymphocytes

circumstantial evidence

how is tolerance maintained

deletion of self reactive lymphocytes

what happens in central tolerance

self reactive T lymphocytes clonally eliminated

what is positive selection

clonal expansion of cells capable of self-MHC restriction

what is negative selection

clonal deletion of cells expressing TCRs capable of recognizing self-antigens in association with MHC molecules

how is cellular activation requlated

anergy

suppression

clonal deletion

if an APC does not provide to costimulatory signal and T lymphocyte receives a negative signal, the cell becomes

anergic

is antigens in tissues are released as the result of trauma or infection, they have potential to

cause severe immune response

what are the ways autoimmunity can be caused

failure of central tolerance

failure of peripheral tolerance

genetic factors in autoimmunity

what is epitope spreading

process by which the immune response spreads from one epitope of an antigenic molecule to another

what happens in SLE

predominant antibody (ANA) directed against nuclear antigens

failure to maintain self-tolerance

what are the common clinical signs of SLE

fever nonerosive polyarthritis, glomerulonephritis, lymph node and splenic enlargement

majority of lesions in SLE are result of

immune complex disease (type III hypersensitivity)

what is dermatomyositis

inflammatory disease of skin, muscles, and vasculature

what is vasculitis seen as a component of

underlying systemic diseases process or adverse reaction to drug or vaccine administration

the pathogenesis of vasculitis involves

type III hypersensitivity