Blood Groups and Transfusions Flashcards
How are blood groups classified?
Based on antigens present on RBC membrane
What is an antigen?
Anything that an antibody perceives as foreign
What is ethnic diversity of blood groups?
B prevalent in Asia, A prevalent in Europe
Why is ‘O’ referred to as ‘universal donor’
Has no antigens but both anti-A and anti-B. antibodies in plasma. Can be given to all groups as won’t cause reaction
Why is ‘AB’ referred to as ‘universal recipient’
No antibodies but both types of antigens - can receive any type of blood as has both types of antigens so no reaction
Describe blood group A
RBCs carry type A agglutinogens (antigens) on surface of cell
Antibody B in plasma
Can receive type A and O
Can donate to type A and AB
Describe blood group B
RBCs carry type B antigens
Antibody A in plasma
Can receive type B and O
Can donate to type B and Ab
What happens upon mixing of incompatible blood groups?
Causes cells to agglutinate (stick together). Aggregation of RBCs can block small blood vessels (microthrombi). Can make tissues hypoxic.
Haemolysis (lysis of RBCs) causes release of Hb and iron (toxic) into blood. This causes renal failure if reaches the kidney
Describe blood group O
Has no antigens, has A and B antibodies
Can donate to A, B, O and AB
Can receive from O
Describe blood group AB
Has no antibodies, has both A and B antigens
Can receive from A, B, O and AB
Can donate to AB
What is effect of micro thrombi during mixing of incompatible groups?
Bleeding - all of coagulation factors used up
What are agglutinogens?
Antigens
What are agglutinins?
Antibodies
