Intro to Hypersensitivity and Type I hypersensitivity

Question 1

What is type 1 hypersensitivity known as?

Answer 1

immediate hypersensitivity

Question 2

What is type 1 hypersensitivity mediated by?

Answer 2

IgE

Question 3

What is an example of a type 1 hypersensitivity response?

Answer 3

anaphylaxis and atopy

Question 4

What is type 2 hypersensitivity known as?

Answer 4

cytotoxic hypersensitivity

Question 5

What is type 2 hypersensitivity mediated by?

Answer 5

Ab and complement/phagocytosis

Question 6

What is type 3 hypersensitivity known as?

Answer 6

immune-complex mediated hypersensitivity

Question 7

What is type 3 hypersensitivity mediated by?

Answer 7

accumulation of immune complexes and response to them

Question 8

What is type 4 hypersensitivity known as?

Answer 8

cell-mediated (delayed type) hypersensitivity

Question 9

What is type 4 hypersensitivity mediated by?

Answer 9

TH cells and/or CTLs

Question 10

What is sensitization?

Answer 10

an abnormal primary response to an antigen such that on subsequent exposure, the individual mounts an excessive or abnormal secondary response that causes disease rather than immunity

Question 11

What is the type of antigen that is responsible for IgE production?

Answer 11

allergy

Question 12

What is IgE synthesized as the result of?

Answer 12

activated B cell and TH2 cytokine interactions

Question 13

Where do IgE cells originate in?

Answer 13

mucosal cells

Question 14

What cell is responsible for the early phase immediate type hypersensitivity reaction?

Answer 14

mast cells

Question 15

What is an special feature of mast cells?

Answer 15

Fc epsilon RI

Question 16

What is Fc epsilon RI?

Answer 16

a high affinity receptor for IgE that makes the binding almost irreversible

Question 17

Where are mast cells located?

Answer 17

in vascular submucosal layers

Question 18

What is the immediate release mediator released from mast cells during IgE mediated degranulation?

Answer 18

Histamine

Question 19

What is the function of histamine?

Answer 19

increased vascular permeability and bronchoconstriction

Question 20

What are the mediators released from mast cells minutes following activation of IgE?

Answer 20

arachadonic metabolites (prosta glandins and leukotrienes) and the platelet activating factor

Question 21

What is the function of leukotrienes?

Answer 21

it is the same as histamine (increased vascular permeability and bronchoconstriction) just more potent

Question 22

What happens hours after IgE is activated?

Answer 22

synthesis of IL4 and IL5

Question 23

What does IL4 do?

Answer 23

acts on T helper 0 to change to T helper 2s and does class switching on B cells to IgE

Question 24

What does IL5 do?

Answer 24

eosinophil activation

Question 25

What is anaphylaxis?

Answer 25

rapid generalized mast cell degranulation followed by eosinopil degranulation

Question 26

What is the initial response to mast cell degeneration in dogs?

Answer 26

vomiting and diarrhea

Question 27

What is atopy?

Answer 27

the genetic disposition for IgE mediated hypersensitivity

Question 28

What is an allergy?

Answer 28

a hypersensitivity reaction

Question 29

What is the low grade fever, lack of appetite and lethargy the day after vaccination caused by?

Answer 29

proinflammatory cytokines - IL1, IL6, and TNF

Question 30

Typically, when can a moderate proinflammatory cytokine response to a vaccination happen (which vaccine)?

Answer 30

after any of the vaccines, can happen after the first

Question 31

When can type 1 hypersensitivity occur (after what vaccine)?

Answer 31

cannot happen after the 1st vaccine, usually after the first or third

Question 32

How long does it take for a type 1 hypersensitivity reaction to occur?

Answer 32

15-30 minutes for reaction

Question 33

Where is IgE bound in b cells?

Answer 33

in the transmembrane part of the cell

Question 34

What are the mediators of the mast cell?

Answer 34

antihistimines and antileukotriens

Question 35

What is the main mediator for t-cell cytokines?

Answer 35

IL31

Question 36

What is IL31 responsible for in dogs?

Answer 36

itching

Question 37

What are the commercial product that inhibits IL31?

Answer 37

cytopoint and apoquel

Question 38

How does cytopoint inhibit IL31?

Answer 38

it inhibits the binding of IL31

Question 39

How does apoquel inhibit IL31?

Answer 39

it affects the Jak-Stat pathway and inhibits the signal from IL31

Question 40

What is the target of oral immunotherapies?

Answer 40

IgA - inhibit t-regulatory cells