Type I hypersensitivity Flashcards
exam 4
IgE-mediated hypersensitivity
type I
antigen will bind to
membrane bound IgE
IgE bind to
mast cells
APC preferentially activate TH2 cells resulting in the production of
IL4 and IL-13
________ drives B cells to produce IgE in response to pollen antigen
IL-4
secondary exposure to pollen, causes the acute release of _________ contents which causes allergic rhinitis
mast cell
early phase mediators for allergy [6]
- histamine
- proteases
- leukotrienes
- prostaglandins
- Platelet Activating Factor (PAF)
- Chemotatic factors for neutrophils and eosinophils
late phase mediators for allergic rxn
cytokines from mast cells, TH2, macrophages and eosinophils
late phase of allergic rxn can be controlled by
corticosteroids that inhibit cytokine production
allergic rhinitis
Hay fever
bronchial asthma
bronchial constriction
breakdown proteins that causes inflammation and releases leukotrienes
proteases
acute urticaria
hives
RAST test
measure specific IgE antibodies
diagnosis of acute allergic disease [2]
- skin prick test
2. RAST test
positive wheal and flare seen in 5-10 minutes
intradermal skin prick test
used to treat acute anaphylatic reaction
epinephrine (adrenaline)
omalizumab
monoclonal antibody that inhibits IgE binding to mast cells
Tx. of Type I allergic rxn. [4]
- remove the antigen
- tx. with antihistamines, antileukotrienes, corticosteroids
- omalizumab
- hyposensitization therapy (shots)
FEV-1
the air that you can inhale
is a marker for the degree of obstruction with your asthma, you will see this decrease with an early and late phase allergic reaction
FEV-1
hyposensitization
desensitization
multiple exposures to increasing concentrations of the antigen results in an increase of IgG ab
desensitization
2 possible reasons for the increase in IgG and the slow decrease in IgE
- activates TH1 cells
2. activates TREG cells to inhibit TH2 cells
