B Cell Mediated Diseases Flashcards
type I hypersensitivity
IgE-mediated; causes anaphylaxis; allergen binds IgE on mast cells causing degranulation
type II hypersensitivity
IgG or IgM-mediated; blood transfusion reactions; antibody directed against cell surface antigens mediates cell destruction via complement activation
type III hypersensitivity
immune complex-mediated; Ag-Ab complex deposited in various tissues induce complement activation and massive infiltration of neutrophils; serum sickness
atopic diseases (mild allergies)
rhinitis, asthma, dermatitis, food allergies, drug allergy
anaphylactic diseases (greater severity)
food and drug allergies, systemic anaphylaxis, urticaria-angiodema
mast cells
high affinity receptors for IgE and abundant in mucosa of respiratory and GI tract and connective tissue
basophils
high affinity receptors for IgE and found in blood
eosinophils
granulocytic cell that is recruited to sites of allergic reaction
type I mechanism
allergen binds B cell antibody and Th2 will bind MHC-II, releasing IL-4 to stimulate B cells to produce IgE –> IgE will bind mast cell –> allergen binds again and degranulation
type I mediators
primary=histamine, secondary=cytokines
IL-1 and TNF-alpha
systemic anaphylaxis
IL-4 and IL-13
IgE production
primary inflammatory cell type
neutrophils
type II hypersensitivity is characterized by _
antibodies that interact with self antigens; transfusion and hemolytic diseases of newborns
