Lecture 23 11/13/23

Question 1

What are the characteristics of blood incompatibilities?

Answer 1

-significant manifestations of type II hypersensitivity
-occur when immune system targets specific antigens on blood cell surface
-occurs after incompatible blood transfusions and certain maternal-fetal interactions

Question 2

What does a type II hypersensitivity result from?

Answer 2

destruction of cells by IgG and IgM antibodies and complement

Question 3

What are blood group antigens/erythrocyte antigens?

Answer 3

molecules expressed on the surface of RBCs

Question 4

When are blood group antigens immunogenic?

Answer 4

when introduced to individuals who naturally lack the antigens

Question 5

What happens when donor red cells/their antigens are identical to those of the recipient?

Answer 5

-no transfusion reactions
-no immune responses

Question 6

What happens when donor red cells/their antigens are NOT identical to those of the recipient?

Answer 6

-response triggered against foreign antigens
-blood transfusion reactions

Question 7

What happens in a blood transfusion reaction?

Answer 7

antibodies against the foreign blood type antigens cause rapid elimination of the transfused blood cells

Question 8

Which mechanisms lead to blood cell destruction during transfusion reactions?

Answer 8

-complement activation
-ADCC

Question 9

What are the symptoms/complications associated with blood transfusion reactions?

Answer 9

-hemoglobinemia
-hemoglobinuria
-blood clotting/coagulation
-acute kidney failure
-anemia
-shock/death

Question 10

Why does type O blood not trigger a response when transfused into individuals with types A, B, or AB blood?

Answer 10

type O blood does not have any antigens for the antibodies to identify/react to

Question 11

What are the characteristics of the blood group system in cats?

Answer 11

-only major blood group is AB
-cats can have types A, B, or AB blood
-majority of cats are type A; very few are type AB

Question 12

How quickly do blood transfusion reactions occur?

Answer 12

within a few minutes

Question 13

Why are transfusions of incorrect blood type most important in cats with type B blood?

Answer 13

nearly all cats with type B blood have naturally occurring anti-A IgM antibodies, and do not need previous exposure to type A blood to have a reaction

Question 14

What are the characteristics of blood typing cards for cats?

Answer 14

-card with a control area and areas to test for A and B antigens
-A and B antibodies are within their respective areas of the card
-if the blood agglutinates within an area, it indicates that the blood has antigens that interact with the antibodies in that space (A antigens w/ A antibodies in the A area)

Question 15

How is a cat blood card read?

Answer 15

-agglutination in only A area = type A blood
-agglutination in only B area = type B blood
-agglutination in both A and B areas = type AB blood

Question 16

What are the characteristics of major cross-matching?

Answer 16

-gold standard
-testing of recipient’s serum against donor RBC antigens prior to transfusions

Question 17

What result is seen in major cross-matching if the donor and recipient are compatible?

Answer 17

-no agglutination
-no hemolysis

Question 18

What result is seen in major cross-matching if the donor and recipient are incompatible?

Answer 18

-agglutination
-hemolysis

Question 19

What are the two types of incompatibility that can occur between human mothers and babies, in terms of blood?

Answer 19

-ABO
-Rhesus (Rh)

Question 20

What are the characteristics of Rhesus incompatibility in humans?

Answer 20

-develops when mother is Rh negative and baby is Rh positive
-mothers become sensitized and develop anti-Rh antibodies during first pregnancy
-subsequent pregnancies with Rh positive children can increase antibody numbers and see antibodies attacking baby’s blood
-can lead to jaundice and anemia in baby

Question 21

What are the characteristics of rhesus incompatibility in animals?

Answer 21

-anti-red cell antibodies can be concentrated in maternal colostrum
-antibodies are absorbed through intestinal wall and into bloodstream, where they destroy baby’s RBCs

Question 22

What are the characteristics of neonatal isoerythrolysis?

Answer 22

-hemolytic disease of newborn foals
-horses with EAA blood type are most commonly affected
-antibodies are concentrated in colostrum and ingested by foal
-cause RBC destruction and jaundice
-due to anti-Aa and anti-Qa antibodies in most cases