Hypersensitivity Flashcards
true allergy or atopy
Type 1 Hypersensitivity
IgE antibody-mast cell mediated in response to antigen
Type 1 Hypersensitivity
sensitization phase
Type 1 Hypersensitivity
first exposure to allergen protein that binds haptens
no reaction
IgE to the allergen is produced long term by the plasma cells and binds to ______ on mast cells
Fc epsilon R1 IgE receptors
elicitation phase
hypersensitivity reaction upon repeat exposure
occurs only after sensitization
allergen cross links the IgE on the mast cell _______
Fc epsilon R1
immediate hypersensitivity is mediated by
vasoactive amines and lipid mediators
late phase hypersensitivity is mediated by
cytokines
mast cells are located in
all connective tissue
Fc epsilon R1
high affinity receptor on mast cells and basophils
ITAM phosphorylation causes
release of preformed mediators
arachidonic acid metabolism secreting lipid mediatiors
activation of cytokine transcription genes to secrete cytokines
histamine is released
upon mast cell degranulation
effect: histamine
vasodilation, increased vascular permeability, smooth muscle contraction, mucous production
proteases are released upon
degranulation
proteases cause
tissue damage
prostaglandins are released
arachidonic acid metabolism
prostaglandins cause
vasodilation
leukotrienes are released
arachidonic acid metabolism
leukotrienes cause
prolonged smooth muscle contraction
synthesized THF-a causes
endothelial cell activation
inflammation
neutrophil activation
synthesized IL-4 causes
IgE class switching by B cells
synthesized IL-5 causes
eosinophil generation and activation
antihistamines
reduce the potential for histamine to bind and cause symptoms
H1 antagonists: first gen
antihistamines that cause sedation, short acting
first gen H1 antagonists: drug names
diphenhydramine, hydroxyzine, doxepin, cyproheptadine
H1 antagonists: 2nd gen
antihistamines that are long acting, little to no sedation
H1 antagonists: 2nd gen drug names
cetrirzine, levocetirizine, loratadine, desloratadine, fexofenadine
H2 antagonists
receptors mostly in gut
indigestion/heartburn
H2 antagonists: drug names
ranitidine and famotidine
1st line in anaphylaxis
epinephrine
montelukast, zafirlukast
leukotriene receptor antagonists
relax bronchial smooth muscle
administration: corticosteroids
inhaled, topical, oral, IV, IM
allergy shots are
desensitization
repeated increasing dose of allergens to help the system overcome the allergy
desensitization
cromolyn
inhibits mast cell degranulation
mepolizumab
reslizumab
benralizumab
anti IL-5 therapy
duplimab
anti IL-4, IL-13 therapy
clinical use: duplimab
atopic dermatitis in adults
asthma
antibodies can be directed against cells or extracellular matrix components
Type II
antibodies/antigens can bind and be directly deposited in blood vessels
Type III