Hypersensitivity Flashcards
Eosinophils represent what kind of hypersensitivity
Type 1
Chronic allergic inflammation –> major contributor to tissue damage
Type 1 hypersensitivity involves what Ig?
what cells have high affinity for this Ig?
IgE
Mast cells and basophils have high-affinity for FCeRI CD23a receptor
what are the only cells that contain histamine
mast cells
basophils
in the type 1 sensitization to allergens, the first exposure to allergen is called priming in which IgE binds to mast cells. Does this result in allergic symptoms?
NO
IgE binds to what receptor on Mast cells and basophils
FceRI (CD23a) receptor
in Type 2 hypersensitivity the damage done depends on?
amount of Ag on target cells
what are some Type 2 hypersensitivity antibody-mediated diseases
goodpasture syndrome myasthenia gravis rheumatic fever thrombocytopenic purpura autoimmune hemolytic anemia
some treatment options for type2 include anti-CD20 and anti-CD52 what does this do?
anti-CD20: B-cell non–hodgkins lymphoma
anti-CD52: B and T cells –> leukemias
what is mysthenia gravias
type 2 rxn
Abs against ACh receptors
what is mysthenia gravias
type 2 rxn
Abs against ACh receptors
what is type 2 vs type 3 hypersensitivity
type 2 =Antibody mediated = Fixed Ag
type 3 = Immune-complex mediated = soluble Ag
how are immune complexes removed?
• CR1 on RBC binds circulating immune complexes coated with C3b and C4b and transports to liver & spleen
when inflammed immune complexes act on what cells causing release of?
basophils and platelets –> release of amines (histamine, tryptamine –> increase permeability –> complex deposition in vessel walls –> complement activation
some clinical manifestations of type 3 rxn?
nephritits, arthritis, vasculitis
what are some type 3 diseases?
serum sickness SLE Post-strep glomerulonephritis Arthrus Rxn Farmers lung = hypersensitivity pneumonitis
