Type 2-4 Hypersensitivity

Question 1

What type of antigen is associated with type II hypersensitivity?

Answer 1

a cell surface antigen

Question 2

What antibodies are associated with type 2 hypersensitivity?

Answer 2

IgG and sometimes IgM

Question 3

What do the clinical signs of type 2 hypersensitivity result from?

Answer 3

the destruction or dysfunction of the target cell

Question 4

What are the cellular targets for type 2 hypersensitivity?

Answer 4

red blood cells, skin, neuromuscular junction, and platelets

Question 5

What are the mechanisms for destruction of cells/tissues in type 2 hypersensitivity reactions?

Answer 5

complement fixation and cell lysis, opsinization and phagocytosis of free floating cells, antibody dependendent cell mediated cytotoxicity

Question 6

What are some diseases/conditions resulting from a type II reaction?

Answer 6

pemphigus foliaceous, autoimmune hemolytic anemia, myasthenia gravis

Question 7

What is the target of pemphigus foliaceous?

Answer 7

skin cells

Question 8

What mechanism does pemphigus foliaceous use?

Answer 8

antibody binds to the cell adhesion molecule

Question 9

What does autoimmune hemolytic anemia target?

Answer 9

red blood cells

Question 10

What is the target of myasthenia gravis?

Answer 10

acetylcholine receptor

Question 11

What type of antigen is associated with type III hypersensitivity?

Answer 11

a soluble antigen

Question 12

What antibody is associated with type 3 hypersensitivity?

Answer 12

IgG

Question 13

What is the mechanism used for cell destruction in type 3 hypersensitivity?

Answer 13

complement activation via the classical pathway

Question 14

What cell type is usually involved with type 3 hypersensitivity?

Answer 14

neutrophils

Question 15

What are mast cells activated by in type 3 hypersensitivity?

Answer 15

anaphylatoxins produced by complement fixation

Question 16

What do the clinical signs of type 3 hypersensitivity result from?

Answer 16

complement, neutrophil, macrophage, and mast cell activation at the site of the immune complex deposition

Question 17

What are the type of reactions associated with type 3 hypersensitivity?

Answer 17

local and generalized reaction

Question 18

What is the local type 3 hypersensitivity reaction kalso nown as?

Answer 18

the arthus reaction

Question 19

How long does it to take for the arthus reaction to occur?

Answer 19

about 2-8 hours after exposure

Question 20

How does the arthus reaction work?

Answer 20

after the antigen is introduced into the tissue, antbody in circulation binds to it formin immune-complexes that stay localized and induce inflammation at the site of antigen introduction

Question 21

How does generalized type 3 hypersensitivity reactions work?

Answer 21

the antigen in antibody are in the circulation allowing the immune-complexes to circulate and get deposited at blood filtration points

Question 22

How long does it take for the generalized type 3 hypersensitivity reaction to work?

Answer 22

7-10 days upon first exposure and 1 -2 days upon second exposure

Question 23

What clinical signs are usually found at sites of immune complex deposition?

Answer 23

vasculitis, synovitis, nephritis, and neurological signs

Question 24

What are the differences in antibody between type I and type III hypersensitivity reactions?

Answer 24

type I is IgE, type III is IgG

Question 25

What is the difference in time between type I and III hypersensitivity reactions?

Answer 25

type I takes 10-15 minutes, type III takes 5-6 hours for initial response

Question 26

Neutrophils are associated with what type of hypersensitivity reaction?

Answer 26

type III

Question 27

Eosinophils are associated with what type of hypersensitivity reaction?

Answer 27

type I

Question 28

What Is an example of a systemic (generalized) type III hypersensitivity reaction?

Answer 28

serum sickness

Question 29

What is type 4 hypersensitivity also known as?

Answer 29

Delayed type hypersensitivity

Question 30

What antigen is associated with type 4 hypersensitivity?

Answer 30

T- cell (Th or CTL)

Question 31

What mediates type 4 hypersensitivity?

Answer 31

T cells, monocytes, and macrophages

Question 32

True or False: IgA is important in type 4 hypersensitivity.

Answer 32

False - it is not antibody mediated

Question 33

If an animal is not sensitized, how long does it take for a type 4 hypersensitivity to take in effect?

Answer 33

1-2 weeks

Question 34

In a sensitized animal, how long does it take for a type 4 hypersensitivity reaction to take an effect?

Answer 34

24-72 hours

Question 35

Why does it take 24-72 hours for the reaction to take place in sensitized animals?

Answer 35

It takes time for the memory t cells to interact with the antigen, and then takes about 24 hours after exposure for recruitment of macrophages

Question 36

What are some clinical manifestations associated with type 4 hypersensitivity?

Answer 36

induration, erythema, vesicles

Question 37

What does the TB test test for?

Answer 37

the presence of Th1 under the skin

Question 38

What does it mean if there is a hard lump 24-72 hours after being administered the TB antigen?

Answer 38

that there were th1 cells present meaning the patient either had the TB vaccine or they currently have TB