ABO and RhD blood group systems: Importance in transfusion and pregnancy Flashcards
Define transfusion?
Procedure in which donated blood or blood components are transferred into the recipient’s circulation intravenously
Define ABO blood group system?
System used to record the presence of one, both or none of the A and B antigens on RBCs, which are the most clinically significant RBC antigens
How many main blood types are there, and what are they?
8 main blood types
A+, A-, AB+,AB-, B+, B- O+, O-
Define RhD blood group system?
System used to record presence of the rhesus factor D (RhD), a protein found on RBCs
How does a patient’s ABO blood group indicate what serum antibodies they naturally have?
If you have one of the antigens, you will have the opposite serum antibodies
What type of serum RBC antibodies does a patient with blood group A have?
Anti-b antibodies only (attack B antigens on RBC)
What type of serum RBC antibodies does a patient with blood group B have?
Anti-A antibodies only (attack A antigens)
What type of serum RBC antibodies does a patient with blood group O have and why?
Both Anti-A and anti-B antibodies, as they have neither A nor B antigens on RBCs
What type of serum RBC antibodies does a patient with blood group AB have and why?
Neither anti-A antibodies nor anti-B antibodies (so no antibodies)
Because they present A and B antigens on RBCs
What type of serum RBC antibodies does a RhD positive patient have and why?
No RhD antibodies
Because RhD is present on RBCs
What type of serum RBC antibodies does a RhD negative patient have and why?
RhD antibodies
Because RhD is absent on RBCs
In the ABO and RhD blood typing test, how many test tube samples are prepared and why?
3 test tubes for the forward group/typing
3 test tubes for the reverse group/typing
6 test tubes overall
In the ABO and RhD blood typing test, how is forward typing tested?
Detects antigens present on RBCs, by adding patient’s RBCs to control anti-A, anti-B and anti-D antibodies already in test tubes
In the ABO and RhD blood forward typing test, what is meant by agglutination and what does this indicate?
RBCs clump and sink to bottom of tube
The complementary antigens to that antibody are present on the patient’s RBCs
eg. If agglutination occurs in the forward A-antibody tube only, this has occurred because they have clumped together with complementary A antigens on the patient’s RBCs, so this means that the person has blood group A
eg. If agglutination occurs in the forward D-antibody tube, the patients RBCs must express RhD, so they are RhD positive
In the ABO and RhD blood forward typing test, what is meant by no agglutination and what does this indicate?
RBCs don’t clump and can see red liquid in tube
The complementary antigens to that antibody are not present on the patient’s RBCs
In the ABO and RhD blood typing test, how is reverse typing tested?
Detects serum antibodies, by adding patient’s antibodies to test tubes with RBCs that have A,B or D antigens present
In the ABO and RhD blood reverse typing test, what is meant by agglutination and what does this indicate?
The patient’s serum antibodies are complementary to that type of antigen
eg. Agglutination in test tube with A antigen RBCs, so patient serum must contain anti-A, so their blood group is B or O
In the ABO and RhD blood reverse typing test, what is meant by no agglutination and what does this indicate?
The patient’s serum antibodies are not complementary to that type of antigen
eg. No agglutination in the tube with RBCs expressing B-antigens or in tube expressing A-antigens, indicates that patient’s serum doesn’t have anti-B or anti-A antibodies, so their blood type is AB
