hypersensitivity and autoimmunity Flashcards
antibody mediated hypersensitive
type 1,2 and 3
Tcell mediated hypersensitivity
type 4
Type 1 hypersensitivity
immunoglobulin, antigen type and causes
IgE
soluble antigen
allergy
Type 2 hypersensitivity
immunoglobulin, antigen type and causes
IgG
cell or matrix antigen
rheumatic fever
Type 3 hypersensitivity
immunoglobulin, antigen type and causes
IgG
soluble antigen
rheumatoid arthritis
Type 4 hypersensitivity
immunoglobulin, antigen type and causes
TH1 +TH2- soluble antigen
CTL- cell antigen
inflammatory cytokines, toxins etc.
type 1 diabetes, MS, RA
immediate reation in allergy
IgE effects
vasodilation, oedema, vascular congestion
late reactions in allergy
eosinophil, neutrophil and T cell infiltrates
Atopy is
a predisposition to allergy
environmental factors that increase risk of autoimmune disease
prior infection
how does type 2 hypersensitivity occur
an antigen on normal cells attached to IgG or IgM and triggers inflammatory cells
-anti tissue antibody
how does type 3 hypersensitivity happen
antibodies join together with antigen and trigger IgG and IgM immune cells
-immune complex
whats immunological tolerance
unresponsiveness to a specific antigen
prevents adaptive responses that damage
islet damage in type 1 diabetes happens by
CD4+ Th1 T cells
what happens in autoimmune disease
tolerance is lost to self tissues
often due to abnormal selection or lack of control of self reactive lymphocytes
