3.2 Hypersensitivity Flashcards
Anaphylactic (type I) reactions are caused by the Antibody class _____
IgE
____ is Important for class switching to IgE and ____ also plays role
IL4, IL13
______ are antigens that increase the production of IgE
Allergens
Mast cells and basophils have high affinity ____ receptors for IgE which may remain attached for months
Fc
IgE remains isolated in blood for ________, but can remain attached to leukocytes for _____
a few days, months
how is IgE activated?
- IgE attaches to mast cell or basophil which expresses high affinity receptor FcER1
- IgE on mast cell or basophil interacts w/ specific allergen and mast cell becomes activated upon second exposure
- mast cell then releases mediators
what else can interact w/ mast cells and cause release of mediators?
anaphylatoxins
what happens during a second exposure to an allergen?
Immediate hypersensitivity rxn within minutes (found in granules) AND late phase rxn within 2-8 hours (produced by mast cell in membrane)
_______ causes Capillary dilation (blood vessels enlarge), increase in vascular permeability (get fluid rushing into tissue), and causes smooth muscle contraction
Histamine
_______ is the eosinophil chemotactic factor of anaphylaxis
ECF-A
what is found in granules during allergic reaction stimulation? what is newly synthesized?
- granules: histamine, ECF-a
-Newly syn: leukotrienes
when an allergen is inhaled in an asthmatic, there is an Immediate response due to _____ and late response due to _____
histamine, leukotriene
when does the first phase of reaction to allergen occur in an asthmatic?
30 mins
what can mast cell activation and granule release cause in the:
1. GI tract
2. Airways
3. Blood vessels
- diarrhea/vomiting
- phlegm/coughing
- increased lymph flow, edema, inflammation
what are some examples of Atopic/local v systemic anaphylaxis
atopic = asthma, allergic thinitis
systemic = anaphylactic shock