sensitization upon initial exposure:
allergen activation of CD4 T cell
differentation into Th2 cell
IL4,IL5,IL6,IL10 produce stimulate B cells
to produce IgE IgE bind to mast cells,
basophil, eosinophil
Degranulation of sensitized cells:
cause anaphylaxis reaction(shock)
Type 11 hypersensivity
1) blood transfusion reaction
2) hemolytic disease
3) drug-induced by
hypersensitivity
Type lll hypersensitivity (immune complex mediated) :
complex escape phagocytosis and complement
circulate trappedd in organ,joint, tissue trigger mast
cells to gedranulate damage the site
1) localised
immune complex
disease
2) systemic
immune
complex disease
Type IV hypersensitivity
(cell-mediated or delayed
type h/s)
DTH reaction: ThI/Tdth cells cytokines released
migration inhibition factor prevent migration of
macrophages accumulation at site of infection
hypersensitivity response