Hypersensitivity Flashcards
Type I hypersensitivity immune mediator
IgE
Type II hypersensitivity immune mediator
IgG
Type III hypersensitivity immune mediator
IgG
Type IV hypersensitivity immune mediator
T cells
Type I hypersensitivity antigen type
Soluble
Type II hypersensitivity antigen type
Cell-associated or cell-surface
Type III antigen type
soluble
Type IV antigen type
Soluble or cell-associated
Mast cells play a major role in this type of reaction
Type I
Type I reactions are also known as
Immediate-type
Type II reactions are also known as
modified self
Type III reactions are also known as
immune complex
Type IV reactions are also known as
delayed-type
Which T cell type helps in production of IgE?
Th2 (not Th1!)
Only one hypersensitivity reaction starts within minutes of exposure to the antigen
Type I
Type I hypersensitivity reactions only develop against this type of antigen
Proteins (only kind T cell can recognize)
Allergens are usually this kind of enzyme
protease
Features of typical allergen
Low MW; protease; low concentrations; soluble
Array of effector molecules released by mast cells
Histamine; heparin, TNF-alpha, tryptase
Penicillin-induced hypersensitivity is which type
II
Penicillin-induced hypersensitivity can cause RBC destruction through these 2 ways
MAC and antibody opsonization/Fc receptor of phagocytes
Type II involves which complement receptors and Fc receptors
C5a, C5a receptor, Fc-gamma-3
Farmer’s lung type of reaction
III
Bird-Fancier diseases type of reaction
III
Poison ivy type of reaction
IV
Type IV reactions are characterized by this onset timeframe
24-72 hours
The tuberculin reaction is this type
IV
