Type II Hypersensitivity (29)

Question 1

What is type II hypersensitivity called?

Answer 1

antibody-mediated
(mechanism for failed blood transfusion, hemolytic disease)

Question 2

What is hemolytic disease of the newborn called?

Answer 2

erythroblastosis fetalis

Question 3

What are the pathologic immune mechanisms for type II hypersensitivity?

Answer 3

IgM & IgG antibodies against cell surface of extracellular matrix antigens

Question 4

Type II hypersensitivity, or IgG- or IgM- Mediated Cytotoxic Hypersensitivity occurs when _____

Answer 4

antibodies and complement attach to normal cells and cause opsonization and phagocytosis of cells

Question 5

RBCs express cell surface molecules, usually glycoproteins or glycolipids, that act as antigens and are called _______ or _____

Answer 5

blood group antigens
erythrocyte antigens

Question 6

Blood antigens are controlled by _____ and _____

Answer 6

genes
inherited

Question 7

T/F: Animals may possess antibodies against foreign blood group antigens even when never previously exposed to foreign red cells

Answer 7

TRUE
“natural antibodies”
“cross-reacting epitopes”

Question 8

What happens if the mismatched recipient possesses pre-existing antibodies to donor RBCs?

Answer 8

1. transfused RBCs will be immediately attacked
2. IgM bind donor red cell antigens and may cause agglutination or chemolysis, or stimulate opsonization and phagocytosis

Question 9

What is agglutination?

Answer 9

the action of an antibody when it cross-links multiple antigens producing clumps of antigens

Question 10

T/F: Agglutination is another word for blood clotting

Answer 10

FALSE

Question 11

What is hemolysis?

Answer 11

antibody + complement
creates MAC and puts holes in rbc membrane, causing hemoglobin to leak out

Question 12

When does the most severe reaction to transfusion occur?

Answer 12

when large amount of incompatible blood is transfused to sensitized recipient

Question 13

Complement activation also results in _____ production, mast cell degranulation, and the release of vasoactive molecules and cytokines - leads to circulatory shock with hypotension, bradycardia, and apnea

Answer 13

anaphylotoxin

Question 14

If a reaction to a blood transfusion is suspected, what do you do?

Answer 14

1. transfusion must be stopped immediately
2. maintain urine flow with fluids and a diuretic (prevents renal tubular destruction)
3. recovery follows elimination off the foreign red blood cells by phagocytes

Question 15

What are anaphylotoxins?

Answer 15

generated when complement is activated
pro inflammatory
cause permeability, smooth muscle contraction, mast cell degranulation

C5a, C3a, C4a

Question 16

How do you prevent transfusion reaction?

Answer 16

cross-matching

Question 17

What is cross-matching?

Answer 17

testing of the recipient’s serum for antibodies against the donor’s red cells

Question 18

T/F: Womens with a negative Rh factor but a child with Rh +, she will attack the fetus (first pregnancy)

Answer 18

FALSE - will attack fetus on second time

Question 19

What is hemolytic disease of the newborn?

Answer 19

during pregnancy, fetal rbcs leak into the blood stream of their dams through placenta

incompatible? start making antibodies

concentrates in colostrum

Question 20

What are the 4 conditions for hemolytic disease of the newborn to occur?

Answer 20

Question 21

In ___, HDN in foals is seen about 8-10%. Thoroughbred and Standardbreds?

Answer 21

mules
2%

Question 22

T/F: HDN is more likely to occur with horses that have had more than one foal

Answer 22

TRUE

Question 23

The most severe form of HDN results from the production of antibodies against the ___ antigen of the ____ system

Answer 23

Aa antigen
EAA

Question 24

Anti-___ and anti-__ account for a total of 90% of HDN in foals

Answer 24

Anti-Aa
Anti-Qa

Question 25

What are the earliest signs of HDN in foals?

Answer 25

weakness
depression

Question 26

_____, although uncommon, is diagnostic in HDN

Answer 26

Hemoglobinuria

Question 27

HDN in calves is rare but has results from _______

Answer 27

vaccination against anaplasmosis
or babesiosis

Question 28

Cows sensitized by vaccines causing HDN then mated with bulls carrying the same blood groups can transmit _____

Answer 28

colostrum antibodies to their calves, which may develop HDN

Question 29

What is bovine neonatal pancytopenia?

Answer 29

unexplained hemorrhagic disease of newborn beef calves
studies showed that colostrum of dams and these calves contained antibodies against MHC I antigens of neonatal leukocytes and bone marrow stem cells

Question 30

HDN in pigs formerly occurred as a result of the use of _____

Answer 30

hog cholera vaccine containing pig blood

Question 31

What is type II hypersensitivity reactions to drugs?

Answer 31

Question 32

In type Ii hypersensitivity, certain ___ and ___ can be absorbed onto red blood cells and render them immunologically _____

Answer 32

bacteria
viruses
foreign

Question 33

Resulting disease due to destruction of transfused blood cells is due to the ____

Answer 33

lysis of transfused red cells by antibodies and complement

Question 34

Regarding type II hypersensitivity, some vaccines may induce _____ in cows. It then causes ____

Answer 34

anti-MHC antibodies
lethal pancytopenia in calves

Question 35

Some ____ may bind to blood cells and make them targets of antibodies in a type II hypersensitivity reaction

Answer 35

drugs