Exam 4: Dr. Thomason Transfusions and Blood Groups Flashcards
What are transfusions?
Process of receiving blood products into one’s circulation
What are the different types of blood products?
Fresh whole blood
Packed RBCs
Fresh frozen plasma
Platelet concentrations
What are indications for transfusions?
Anemia
Disorders of hemostasis/coagulation
Deficiencies of plasma components
What are the different anemias?
Hemorrhage
Hemolysis
Non-regenerative anemia
What are blood groups?
Inherited antigens on the RBC surface
What do RBC antigens do?
Contribute to self recognition
Elicit the production of antibodies when introduced to an animal whose RBCs lack that antigen
What are the canine blood types?
Dog erythrocyte antigen (DEA) 1.1, 1.2, 3, 4, 5, 6, 7, and 8
Which DEAs are considered to be important in transfusion medicine?
1.1 and 1.2
Describe DEA 1.1
Extremely antigenic
The antigen routinely determined in patients and donors
What percentage of dogs are DEA 1.1 positive?
42%
What are red cell alloantibodies?
IgM, IgG, or IgE antibodies that cause hypersensitivity reactions to blood products
Do dogs have naturally occurring alloantibodies to DEA 1.1?
No
What will happen when a transfusion uses RBCs with similar DEA antigens?
Less likely to mount an immune response due to similar cells
May recognize another antigen
What will happen when a transfusion uses RBCs with different DEA antigens?
The highly antigenic DEA 1.1 antigen is not expressed
Less likely to mount an immune response
What will happen when a transfusion uses DEA 1.1 negative dogs transfuse with DEA 1.1 positive blood?
It will likely become sensitized and produce an anti-DEA 1.1 alloantibody
What are previously transfused patients with circulating alloantibodies are risk for?
Development of the transfusion reactions
What can be used to assess blood compatibility?
RBC antigens and plasma antibody interaction
What is the visible reaction of blood compatibility?
Agglutination
What is agglutination?
The antibody mediated clumping of cells that express antigen on their surface
What does major crossmatch determine?
The compatibility between the donor and recipient
What does major crossmatch prevent?
Incompatible transfusions that could result in immune-mediated hemolytic transfusion reactions
What are donor RBCs incubated with in major crossmatch?
Recipient serum and observed for agglutination/hemolysis
If there is agglutination/hemolysis in major crossmatch, what does it mean?
Incompatible
What are the feline blood types?
Type A
Type B
Type AB
What is the predominant blood type of felines?
Type A
What breeds of cats have the highest frequency of type B blood?
Devon Rex
British Shorthair
What do cats have in regards to alloantibodies?
Naturally occurring alloantibodies
What do type A cats have?
Circulating B-antibodies
What do type B cats have?
Circulating A-antibodies
What happens when antibodies and antigens bind?
Agglutination
When do acute hemolytic transfusion reactions (AHTRs) develop?
When transfused RBCs interact with preformed circulating antibodies in the recipient that are naturally occurring or acquired
What can the interaction between transfused RBCs and circulating antibodies do?
Activate complement and cytokines which leads to a systemic inflammatory response
What is the reaction severity of AHTRs related to?
The number of RBCs destroyed
In dogs, what are AHTRs predominantly?
IgG
In cats, what are AHTRs predominantly?
IgM
What are clinical sign of AHTRs?
Fever Restlessness Salivation Incontinence Shock
Describe febrile non-hemolytic transfusion reactions
A temperature increase associated with a transfusion without any other explanation
Leukocyte-derived cytokine and/or circulating anti-leukocyte antibodies in the recipient
