hypersensitivity and autoimmunity Flashcards
Type 1 characterized by
IgE
type 2 characterized by
antibody binding to cells
type 3 characterized by
antibody-antigen complex
type 4 characterized by
cellular mediated pathology
What do IgE antibodies bind to
mast cells and basophils
what does antigen cross linking 2 or more IgE induce
cellular degranulation and release of mediators
name 3 mediators released in type 1
histamine
protaglandins
leukotrienes
what does histamine do (2)
dilates and increases permeability of blood vessels
smooth muscle contraction
What do prostaglandins do
contract smooth muscle of respiratory system and increase mucus secretion
Leukotrienes
bronchial spasm
What receptors do IgE bind to on mast cells and eosinophils
Fc epsilon receptors
What can degranulation lead to within minutes of antigen exposure
anaphylactic shock, massive drop in blood pressure
GI tract effect because of degranulation
increase fluid secretion and peristalsis—> expulsion of GI tract contents
Eyes, nasal passages and airways effect of Type 1
decreased diameter, increased mucus secretion —>
congestion and blockage of airways
swelling and mucus secretion in nasal passages
Blood vessels effect of type 1
increased blood flow and increased permeability
—> increased fluid in tissues and lymph
The immediate release (granules) type 1
Histamine, TNF alpha, proteases
Minutes release type 1
prostaglandins, Leukotrienes
Hours release type 1
IL-4 IL-3
what does TNF alpha do
cell recruitment
summary of type 1 hypersensitivity reactions
allergic disease
clinical conditions of type 1 hypersensitivity
allergic rhintis, conjunctivitis, asthma, hives hayfever
mechanisms to treat asthma
bronchial dilators
steroids
what are bronchial dilators
short acting beta-2- adrenergic receptor agonist (salbutamol)
2 steroid inhalers
beclometasone
fluticasone