Blood Group Antigens and Antibodies

Question 1

Explain the genetics of blood group antigens: Rhesus systems:

Answer 1

• All blood cells have antigens
• Immunoglobulins are protein (IgG/IgM) produced when exposed to foreign antigen
• Blood groups

Question 2

Explain the genetics of blood group antigens: Blood groups

Answer 2

• Systems include ABO/D

- antibodies are produced in response to antigens only if the recipient lacks the antigen

Question 3

Describe the production of naturally occurring antibodies to blood group antigens:

(Blood Transfusion)

Answer 3

• Blood carrying antigens foreign to the patient

Question 4

Describe the production of naturally occurring antibodies to blood group antigens:

(pregnancy)

(environment)

Answer 4

• Foetal antigen entering maternal circulation

- naturally acquired through environmental factors

Question 5

What are IV Antigen-Antibody reactions?

Answer 5

IV AA reactions can destroy the cell

• direct = intravascular
• indirect = extravascular

IVAA reactions are seen as agglutination tests

Question 6

What is agglutination?

Answer 6

• Clumping of red blood cells which can identify RBC antigen
• or identify presence of antibody in plasma
• D antigen = D positive

Question 7

What can occur with mismatched blood transfusions?

Answer 7

ABO antibodies can cause intravascular haemolysis

• All Rh antibodies can cause transfusion reaction
• Rh antibodies are usually IgG which can cause haemolytic disease of the new born