Transfusions and Blood Groups

Question 1

IMHA treatment

Answer 1

• remove underlying cause
• immunosuppressive therapy
• anticoagulant therapy
• supportive care

Question 2

Transfusion

Answer 2

Process of receiving blood products into one’s own circulation

Question 3

Types of blood products

Answer 3

• fresh whole blood
• packed red blood cells
• fresh frozen plasma
• platelet concentrates

Question 4

Indications for transfusions

Answer 4

• anemia: hemorrhage, hemolysis, non-regenerative
• disorders of hemostasis/coagulation
• deficiencies of plasma components

Question 5

RBC transfusions

Answer 5

• any cause of life-threatening anemia
• acute hemorrhage
• hemolysis
• severe non-regenerative anemia
• neonatal isoerythrolysis

Question 6

Blood groups

Answer 6

Inherited antigens on RBC surface

• species specific
• vary in immunogenicity and clinical significance

Question 7

RBC antigens

Answer 7

• contribute to self recognition

- elicit the production of antibodies when introduced to an animal whose RBCs lack that antigen

Question 8

Canine blood types

Answer 8

Dog erythrocyte antigen (DEA) system

• 1.1, 1.2 - 8
• 1.1, and 1.2 are considered important in transfusion medicine (produce the greatest immune response)

Question 9

DEA 1.1

Answer 9

Extremely antigenic

• DEA 1.1 positive express the antigen
• 42% of dogs

Question 10

What is the first antibody class that is synthesized by the primary immune response

Answer 10

IgM

- efficient at binding complement

Question 11

What is produced during a secondary immune response?

Answer 11

IgG

Question 12

Red cell alloantibodies

Answer 12

IgM, IgG, or IgE antibodies that could cause hypersensitivity reactions to blood products

Question 13

Do dogs have naturally occurring alloantibodies?

Answer 13

NO
Requires sensitization (transfusion) for alloantibodies to develop

Question 14

Transfusion with similar DEA antigens and no alloantibodies

Answer 14

Less likely to mount an immune response

Question 15

Transfusion with recipient positive DEA 1.1 and donor negative DEA 1.1

Answer 15

DEA 1.1 negative does not express 1.1 antigen, so less likely to mount an immune response

Question 16

Transfusion with recipient negative DEA 1.1 and donor positive DEA 1.1

Answer 16

Will become sensitized and produce an anti-DEA 1.1 alloantibody
- does not happen immediately

Question 17

Previously transfused patients

Answer 17

At risk for developing transfusion reactions

- risk complement destroying transfused blood immediately (acute hemolysis)

Question 18

Blood typing

Answer 18

RBC antigens and plasma antibody interaction can be used to assess compatibility

Question 19

Agglutination

Answer 19

Antibody-mediated clumping of cells that express antigen on their surface

Question 20

Will the very first transfusion a dog receives cause a reaction?

Answer 20

No, since there are no antibodies free floating in the body at this point

Question 21

Major crossmatch

Answer 21

Determine compatibility between donor and recipient

• donor RBCs are incubated with recipient serum and observed for agglutination or hemolysis
• if no agglutination/hemolysis then you are safe to transfuse

Question 22

Minor crossmatch

Answer 22

Compatibility: donor plasma and recipient

Question 23

Feline blood types

Answer 23

3 main blood types

• A
• B
• AB

Question 24

Feline type A

Answer 24

Predominant blood type

• varies with breed and location
• type B: devon rex, and british shorthair

Question 25

Do cats have naturally occurring alloantibodies?

Answer 25

Yes - some A cats have antibodies against B blood - MOST B cats have antibodies against A blood

Question 26

What happens if you give a B recipient A type blood?

Answer 26

Will get an immediate hemolytic response

Question 27

Actue hemolytic transfusion reactions

Answer 27

Develops when transfused RBCs interact with preformed circulating antibodies in the recipient that are naturally occurring or acquired - can activate complement and cytokines = systemic inflammatory response

Question 28

AHTRs

Answer 28

- reaction severity is directly related to number of RBCs destroyed - dogs: reactions are predominantly IgG - cats: reactions are predominantly IgM

Question 29

AHTR clinical signs

Answer 29

- fever - restlesness - salivation - incontinence - shock

Question 30

Febrile non-hemolytic transfusion reactions

Answer 30

- temperature increase associated with a transfusion without other explanation - leukocyte derived cytokine and/or circulating anti-leukocyte antibodies in the recipient