Hypersensitivity Flashcards
What is hypersensitivity
Hyperactive immune responses against “harmless” antigens
auto-immunity
Type of hypersensitivity that is caused by a breakdown in the mechanisms that normally ensure tolerance of self
What is the most common type of hypersensitivity
Type 1 (the allergic response)
What individuals are predisposed to having a type 1 hypersensitivity reaction
atopic indviduals
What type of antibodies recognize the allergen
IgE
What type of cell does the IgE antibody bind to, what part of the antibody binds
Mast cell, Fc
Where are mast cells found
Mucosa
T/F: An allergen will cross link IgE on mast cells triggering degranulation
True
What occurs when mast cells degranulate
allergy symptoms from mediators, recruitment of basophils from blood
What occurs in the late phase of type 1 hypersensitivty
mediators recuit other inflammatory cells (eosinophils and neutrophils)
What are the mediators of type 1 hypersensitvity
Histamine, prostaglandins, leukotrienes, TNF-alpha and IL-4
What does the mediator histamine cause
vasodilation, increased capillary permeability, smooth muscle contraction (bronchospasm)
What does the mediator prostaglandins cause
bronchoconstriction, attract white blood cells
What does the mediator leukotrienes cause
Capillary permeability (longer duration)
What do the mediators TNF-alpha and IL-4 do
inflammation, cytokine release that stimulates T helper 2 cells