Type 1 Hypersensitivity

Question 1

true immediate type reaction is mediated by this

Answer 1

IgE

Question 2

luekotrienes that are produced in type 1 HS

Answer 2

C, D, E (slow reacting substance of anaphylaxis)

Question 3

IgE binds to Fc receptor on these cells

Answer 3

mast cells and basophils

Question 4

complement components C3a and C5a can bind to this receptor, which will cause non-IgE mediated type 1 HS

Answer 4

CR1

Question 5

what is receptor for histamine induced smooth muscle contraction?

Answer 5

7 spanning GPCR

Question 6

what occurs in early/acute phase of type I HS? (mediated by mast cell activation -> histamine, leukotrienes)

Answer 6

contraction SMC and immediate inflammation/edema

Question 7

what mediates early/acute phase type 1 HS?

Answer 7

mast cell activation (release histamine, producing leukotrienes)

Question 8

these cells mediate late phase of type 1 HS; what recruits these cells?

Answer 8

eosinophils, neutrophils, monocytes, cytokines; mast cell mediators

Question 9

peak reaction to histamine occurs within this time period

Answer 9

20 min

Question 10

what is released from granules in activated mast cells?

Answer 10

histamine, proteases, chemotactic factors

Question 11

what must given to EVERY patient that is presenting with asthma (helps treat late phase reaction)

Answer 11

corticosteroid

Question 12

where are mast cells found in local lesions of type 1 HS?

Answer 12

subepithelial tissues near BV

Question 13

early morphology of type 1 HS

Answer 13

mast cells, edema/erythema, SMC contraction, mucus secretion

Question 14

localized tissue reactions of type 1 HS

Answer 14

allergic rhinitis, allergic asthma, urticaria, wheal/flare

Question 15

treatment for clinical syndromes of type 1 HS

Answer 15

antihistamines, anti-leukotrienes, steroids

Question 16

what determines clinical syndrome of type 1 HS

Answer 16

route of exposure

Question 17

symptoms/signs of anaphylaxis

Answer 17

tissue swelling, bronchoconstriction, laryngeal edema (difficult to reverse), peripheral vasodilation/hypotensive shock

Question 18

this is required for anaphylaxis to occur

Answer 18

vascular dissemination allergen

Question 19

mainline treatment for anaphylaxis

Answer 19

antihistamines and epinephrine

Question 20

symptoms of anaphylaxis (in order of greatest frequency)

Answer 20

urticaria/angioedema, bronchoconstriction, dizziness/syncope (hypotension), GI symptoms (NVD), peripheral vasodilation/flushing

Question 21

tx of choice in anaphylactic and anaphylactoid reactions

Answer 21

epinephrine (in combo with antihistamines)

Question 22

this tests for total serum amount of IgE

Answer 22

RIST

Question 23

this tests for serum amount of antigen-specific IgE

Answer 23

RAST

Question 24

what mediates type 1 HS?

Answer 24

mast cells (IgE binding Fc receptor)

Question 25

this receptor is cross-linked in type 1 HS -> causes release of mediators (histamine, leukotrienes)

Answer 25

IgE Fc receptor

Question 26

this kind of antigen is essential for type 1 HS reaction

Answer 26

multivalent

Question 27

what controls IgE mediated type 1 HS

Answer 27

CD4, TH2 pathway/IL4/IL5

Question 28

what portion of IgE is cross linked?

Answer 28

Fab

Question 29

this cytokine regulates IgE synthesis (stimulates naive IgM/IgD to IgE)

Answer 29

IL-4

Question 30

lipid mediators that are synthesized and act within 1-2 hours in early/acute type 1 HS

Answer 30

LTB4, LTC/D/E, PGE, PAF

Question 31

morphology of type 1 HS

Answer 31

mast cells (subepithelial tissue), edema, erythema, acute inflammatory infiltrate, eosinophils

Question 32

basic proteins located in eosinophils -> toxic to cells and parasites

Answer 32

major basic protein, eosinophilic cationic protein, neurotoxins

Question 33

this stimulates eosinophil production in bone marrow

Answer 33

IL-5

Question 34

Fc receptor expressed by activated eosinophils

Answer 34

FceRI

Question 35

induces degranulation of eosinophils

Answer 35

eotaxin, C5a, antigens

Question 36

what usually causes anaphylaxis

Answer 36

rapid systemic distribution of allergen

Question 37

these are examples of anaphylactoid reactions causing widespread mast cell degranulation

Answer 37

anesthetic agents, snake venom (complement activation), ASA

Question 38

this reverses effects of histamine on bronchoconstriction and vasodilation

Answer 38

epinephrine

Question 39

manifestation of an allergy is dependent on this

Answer 39

mast cell distribution (at site of exposure)