Transfusion

Question 1

What are antigens?

Answer 1

Protein, carb, or lipid structures on the red cell membrane.
ABO antigens are carbs.
Rh antigens are proteins.

Question 2

What are antibodies?

Answer 2

Immunoglobulins; specific binding to corresponding antigen facilitating destruction of whatever structure antigen is on.

Question 3

How are antibodies formed?

Answer 3

Typically a complex process; however, the body can make antibodies when sensitized to antigens via vaccination, pregnancy, and transfusion.

Question 4

Name blood groups and their associated antigen and antibody?

Answer 4

Blood Group; A, B, AB, O
Antigen; A, B, -, AB
Antibody; anti-B, anti-A, anti-AB, -

Question 5

How are antigens and antibodies detected?

Answer 5

Detection reactions are observed using different techniques but are largley based on haemagglutination.
Patients are incubated with cells of known phenotypes which allows any antobodies in the patients plasma to attach to the corresponding antigens. (e.g. in ABO blood grouping IgM antibodies will directly agglutinate red cells carrying the appropriate antigen)

Question 6

What is agglutination and haemagglutination?

Answer 6

Haemagglutination is defined the formation of clumps of red blood cells by specific antibodies to surface antigenic components.

Question 7

How is manual cross matching done?

Answer 7

Test the patients plasma against donor red cells using agglutination and indirect antiglobulin tests.

Question 8

What are transfusion reactions?

Answer 8

Medical complications that arise after a blood transfusion and can occur in multiple ways.

Question 9

Name 3 forms of transfusion reactions.

Answer 9

Haemolytic transfusion reaction
Febrile reaction
Anaphylaxis

Question 10

What are some blood products available?

Answer 10

Red Cells; plasma and leucocytes removed from red cell products, has a shelf life of 120 days.
Platelets; aids in clotting process, shelf life of 5-7 days.
Fresh frozen plasma; must be of a specifc type, thawed in hot air with a shelf life of 2 years.

Question 11

Describe ABO blood group system transfusion.

Answer 11

In terms of transfusiing red cells, group O would be given. In terms of transfusing fresh frozen plasma, we tend to give something that doesnt have many antobodies hence group AB.