Blood Group Antigens

What can cause sensitization in the mare, donkey, and human? How many pregnancies are necessary for a reaction?

must have more than pregnancy; small placental hemorrhages allow fetal erythrocytes to enter maternal circulation and sensitization to the paternal blood group antigens occurs

What is the significance of the mechanism of NI or HDN?

neonates cnat nurse from the mother if they have different blood types

How can transfusion reactions in dogs be prevented?

1) type and cross-match (easy tests available) or 2) use DEA 1.1-negatvie blood for transfusion

What are blood group antigens made of?

usually polysaccharides (glycolipids)

What would be the effect in the foal that ingests colustrum from the mismatched mare?

will be anemic

How will the type A kittens be introduced to the Type A antibodies of the mother?

will receive natural antibodies to type A blood group when they ingest colostrum

When does Neonatal Isoerythrolysis occur?

occurs after absorption of maternal antibodies in colustrum

What is the neonate's source of antibodies in the human?

placental transfer

What are isoantibodies? Do they need exposure to be formed?

pre-formed antibodies that do not require prior exposure to other RBCs

What leukocytes were primarily destroyted?

primarily lymphocytes and neutrophils

What is the likelihood of a reaction occurring if a DEA 1.1 dog recieves DEA 1.1- blood?

reaction is unlikely; could get a mild reaction, but not serious or noticeable

What happens if a DEA 1.1- dog receives DEA 1.1 blood for its second blood transfusion a few years later?

reaction is very likely since the dog developed antibodies after the 1st transfusion

Which type of dogs usually will have a transfused reaction?

reactions are usually observed in DEA 1.1-negative dogs transfused with DEA 1.1-postive blood (twice)

What is required for a dog to have a trasfusion reaction?

requires prior transusion with mismatched blood

What happens if a DEA 1.1- dog receives DEA 1.1 blood for its first blood transfusion ever?

sensitization is very likely; the dog does not have natural antibodies, but receiving the DEA 1.1 blood will induce an immune response

If a type B cat receives Type A or Type AB blood, will/when there be a reaction?

severe reaction on first transfusion; Type B cats have a high level of IgM isoantibodies, 1 ml of blood could be lethal!

What type of anemia will a few calves have?

some cavles had a non-regenerative anemia

What is the most common clinical findings of Bovine Neonatal Pancytopenia?

spontaneous bleeding

Are isoantibodies present in Type B cats? If so, what is the type of Igs?

strong IgM anti-A

What does the minor cross-match test for?

tests to see if the donor has antibodies agaisnt the recipients blood

What does the major cross-match test for?

tests to see if the recipient has antibodies against the donor's blood

What hypersensitivity reaction is occuring during a blood transfusion?

type 2 hypersensitivity

Are isoantibodies present in Type A cats? If so, what is the type of Igs?

type A has weak IgM and IgG anti-B

What is the best way to prevent a transfusion reaction?

type all donors and recipients and cross-match! (best for dogs to receive DEA 1.1 negative if you don't test)

How can transfusion reactions in cats be prevented?

type and cross-match!!

When can a reaction occur in the mare?

usually 2 or more mismatched pregnancies are necessary to develop sufficient IgG levels.

Are blood group antigens inherited? How many systems exist?

usually have a complex mode of inheritance; multiple systems exist in each species

What type of antibodies are isoantibodies (affinity and type of Ig)?

usually low affinty, IgM

Are isoantibodies common in humans?

yes (ABO blood groups)

Can a transfusion reaction occur if a type B cat recieves type A blood on the 1st transfusion?

yes, a severe transfusion reaction to type A blood will occur on the very 1st transfusion

Are tests available for DEA 1.2?

yes, but in a reference lab

Are tests available for DEA 1.1?

yes, in-clinic kit

Are tests available for blood typing cats?

yes, in-clinic kit for all types

What causes sensitization in the horse?

a mare bred to a mismatched sire

If a type A cat receives Type B or AB blood, will/when there be a reaction?

a mild reaction is possible on the first transfusion

Can a transfusion reaction occur if a type A cat recieves type B blood on the 1st transfusion?

a mild transfusion reaction to type B glood may occur on the 1st transfusion given to a type A cat

In mules, what are the blood group antigens commonly associated with NI?

a unique antigen of doneys is involved; the "donkey" antigen

how is the major cross-match carried out?

add the donor's RBCs to the recipient's serum; check for agglutination or lysis

Which blood type is geneticaly dominant?

Type A

What are the three blood group antigens in cats?

Type A, Type B, and Type AB

Which blood type is rare in cats?

Type AB, this is very rare because the cat had to inherit it as a third allele (usually cats are A or B, not both as in humans)

When may an NI occur in the cat?

Will occur if a type B queen is bred to a type A tom.

How is the minor cross-match test carried out?

add the donor's serum to the recipients RBCs; check for agglutination/lysis

If a type B queen is bred to a Type A tom, what will be the blood type of the kittens?

all will be type A

Which type is most common?

almost all cats in the USA are type A, with the exception of certain breeds with high frequency of type B

What results in a mismatched mare and sire?

an Aa or Qa-negative mare bred to an Aa or Qa-positive sire; also mare bred to a donkey

What is the case fatality rate of Bovine Neonatal Pancytopenia?

at least 90%

What is different from the cat compared to the horse and mule?

cat has natural antibodies, reaction will occur the first time kittens nurse

What is the neonate's source of antibodies in the horse, mule, or cat?

colostral transfer

In which animals are blood group antigens most significant?

dogs, cats, and horses

What is the frequency of Type B blood?

high in certain breeds

Is the antigenicity of DEA 1.1 high or low?

high, very likely to produce an immune response

What happened when a few cows received the vaccine?

made an immune reseponse to the antigens

If a DEA 1.1 dog donates blood to a DEA 1.1 or a DEA 1.1- dog donates blood to a DEA 1.1- dog, what is the result?

matched, no reaction, will not produce antibodies

What are blood group antigens?

membrane antigens

Which cross-match test is not as clinically significant?

minor cross match- antibodies are diluted and become less important

Is the antigenicity of DEA 1.2 high or low?

moderate, not as important

What is assumed to be the cause of isoantibodies?

most are assumed to be due to the presence of gut bacteria that have cross-reactive antigens

Are isoantibodies present in Type AB cats? If so, what is the type of Igs?

no

Are isoantibodies present in dogs for DEA 1.1 or DEA 1.2?

no

Are isoantibodies common in domestic animals?

no, but some species do have these antibodies that recognize blood types they don't have, even if they have never been exposed to that blood type

If a type A cat receives Type A blood, a type B cat receives Type B blood, or a type AB cat receives type AB blood, will there be a reaction?

no, their types are matched

Is NI always clinically apparent?

not clinically apparent in all mismatched breedings, even if antibodies are present. About 1-2% of mares have detectable Abs, and up to 10% mule pregnancies have detectable Abs.

In humans, what are the only clinically significant blood group systems?

ABO and RH

In horses, what are the blood group antigens commonly associated with NI?

Aa or Qa

What happened when the calves ingested colustrum?

Abs were absorbed and caused destruction of platelets and leukocytes

What is the name of the adverse effect of vaccination using a particular brand of vaccine for Bovine Viral Diarrhea virus (BVDV) that was used in Europe and New Zealand?

Bovine Neonatal Pancytopenia (BNP)

What is the most important blood group antigen in the dog for transfusion reactions?

DEA 1

Which allele of DEA 1 is most clinically significant?

DEA 1.1, sometimes DEA 1.2 (DEA 1.3 is not)

What are the canine blood group antigens?

Dog Erythrocyte Antigen (DEA) (8 exist, 1-8)

What are the mechanisms of damage in a blood transfusion?

1) complement mediated, 2) macrophage-mediated (opsonization in spleen and bone marrow), 3) agglutination, 4) Coagulation System Activatio

What is the antigen frequency for DEA 1.1?

33-45%, much more common than DEA 1.2 which is 4-22%

What is the frequency of Type AB blood?

<1%

What is the frequency of Type A blood?

> 99% DSH/DLH in the USA

A dog gets a blood transfusion and an hour later becomes lethargic, gains a fever, and you find hemoglobinemia and hemoglobinuria. You later discover the dog received a blood transfusion 6 years earlier. What is the diagnosis. Why?

Blood transfuion reaction; The dog was DEA1.1- and received DEA1.1 blood. After the first transfusion, DEA1.1 antibodies developed ("sensitization"). The next trasfusion must have been DEA1.1 blood and the dog developed a blood transfusion reaction against the DEA1.1 blood.

What are "natural" antibodies to blood group antigens that can occur in some species?

Isoantibodies

What was the antigen of the vaccine that caused BNP?

MHC class 1 molecules of the cell line used to grow the virus for the vaccine

What are the two major ways to cross-match?

Major and Minor

What is the name of the disease in which hemolysis is caused by maternal antibodies to blood group antigens of the newborn animal?

Neonatal Isoerythrolysis (NI) or Hemolytic Disease of the Newborn (HDN)