Exam 2- Types II and III Hypersensitivity

Question 1

what antibody classes mediate types II and III hypersensitivity?

Answer 1

IgM and/or IgG

Question 2

what are type II hypersensitivity reactions stimulated by?

Answer 2

binding of antibody directly to an antigen on the surface of a cell

Question 3

what are type III hypersensitivity reactions stimulated by?

Answer 3

immune complexes of soluble antigens with antibody (essentially IgG)

Question 4

what mediates type II hypersensitivity?

Answer 4

antibodies against target antigens that are either normal or altered cell membrane components

Question 5

what are the mechanisms of type II hypersensitivity?

Answer 5

activates complement:
lysis of cell
opsonization through surface receptors for Fc or C3b leading to phagocytosis

Question 6

what are isohemagglutinins?

Answer 6

natural antibodies to donor red blood cells antigens

Question 7

are isohemagglutinins usually apparent in serum or plasma if the host has not been exposed to foreign red blood cell antigens?

Answer 7

no

Question 8

___ antibodies mediate destruction of red blood cells by complement-mediated lysis because ___ is very efficient in activating complement

Answer 8

IgM
IgM

Question 9

what does major crossmatch involve?

Answer 9

donor red blood cells and recipient serum or plasma

Question 10

what does minor crossmatch involve?

Answer 10

recipient red blood cells and donor serum or plasma

Question 11

why should cats be crossmatched before their first transfusion?

Answer 11

presence of naturally occurring antibodies

Question 12

how many major blood group antigens do dogs have?

Answer 12

eight

Question 13

what natural isohemagglutinins do dogs have?

Answer 13

against 3, 5, and 7

Question 14

what blood groups are of clinical significance in dogs?

Answer 14

DEA 1.1 and DEA 1.2

Question 15

how many blood groups do equines have?

Answer 15

over 30, 7 internationally recognized

Question 16

what is hemolytic disease of the newborn?

Answer 16

newborn inherits a red cell antigen from its sire that is not present in its mother
mother sensitized to the red cell antigen
mother’s response boosted by transplancental hemorrhage in late gestation
young animal ingests high levels antibodies to its red blood cells in colostrum

Question 17

what species is hemolytic disease of the newborn found in?

Answer 17

dogs
cats
equines

Question 18

what will autoantibodies cause?

Answer 18

impair cellular function without causing cell injury or inflammation or mediate target cell destruction by antibody dependent cell-mediated cytotoxicity

Question 19

how are cats exposed to antigens mimicking blood group antigens?

Answer 19

widely distributed in nature
maybe absorb through gut

Question 20

true/false: many isohemagglutinins appear in serum or plasma before the host is exposed directly to foreign red blood cell antigens

Answer 20

false: most do not appear in serum before this because they are not always expressed by microbes or environmental substances

Question 21

what can result in hemaglobinemia and hemaglobinuria?

Answer 21

hemolysis due to IgM mediated destruction of red blood cells by complement

Question 22

what crossmatch is to be performed if plasma is being transfused?

Answer 22

a minor crossmatch: recipient red blood cells and donor plasma

Question 23

what are the blood groups in cats?

Answer 23

one blood group: feline AB with two blood types: type A and type B
rare AB

Question 24

what blood group reaction in cats has the stronger agglutinins and hemolysins?

Answer 24

in B cats, the anti-A antibodies have them, especially of IgM class
A cats have weaker, of both IgM and IgG

Question 25

true/false: hemolysis reactions to blood transfusions are always delayed-type hemolysis in dogs

Answer 25

true

Question 26

what happens if a dog negative for blood group antigens 3, 5, and 7 receives blood from a dog with one or more of the three?

Answer 26

delayed type hemolysis: 7-10 days

Question 27

true/false: you can transfuse blood relatively safely into a dog without crossmatching it first

Answer 27

true: do not have isohemagglutinins against DEA 1.1 or 1.2

Question 28

what are the antibodies against blood types in dogs that can cause acute hemolytic reaction?

Answer 28

DEA 1.1 and 1.2 only

Question 29

what blood types in horses are most important for hemolytic reactions? do horses have these antibodies naturally?

Answer 29

Aa and Qa no have Ca naturally but only weak agglutination and hemolytic cross-match

Question 30

what can a direct Coombs test determine in autoimmune hemolytic anemia?

Answer 30

whether or not the cause is antibodies attached to the surface of red blood cells

Question 31

what can an indirect Coombs test determine? Is it used to diagnose autoimmune mediated hemolytic anemia?

Answer 31

looks for free-flowing antibodies against red blood cells can determine whether patient may have reaction to a blood transfusion no

Question 32

what are the autoantibodies directed against in myasthenia gravis?

Answer 32

alpha chain of muscle nicotinic acetylcholine receptors

Question 33

what is acantholysis and where is it seen?

Answer 33

separation of keratinocytes from each other pemphigus: skin disease

Question 34

what is pemphigus foliaceus caused by?

Answer 34

autoantibody response against desmoglein-1: responsible for cell-to-cell adhesion of superficial keratinocyte layers

Question 35

what are type III hypersenstivity reactions caused by?

Answer 35

deposition of soluble antigen-antibody complexes

Question 36

what is the prototype of multiorgan or systemic immune complex type III hypersensitivity?

Answer 36

serum sickness and systemic lupus erythematosus

Question 37

what was serum sickness historically observed in?

Answer 37

diphtheria patients treated with horse anti-diphtheria toxin serum

Question 38

in systemic lupus erythematosus, what are autoantibodies produced against?

Answer 38

nucleic acid nucleoproteins histones

Question 39

what are the histologic appearances of the aggregates of immune complexes in systemic lupus erythematosus?

Answer 39

lumpy-bumpy deposits

Question 40

what does laboratory diagnosis of systemic lupus erythematosus focus on?

Answer 40

antinuclear antibodies

Question 41

what leads to release of lytic enzymes in type III hypersensitivity?

Answer 41

failure of neutrophils to ingest adhering immune complexes

Question 42

what is pneumonitis in cattle?

Answer 42

localized type III hypersensitivity reaction: neutrophil accumulation and inflammation due to inhaling thermophilic actinomycetes