Knowledge Check

True of false: crossmatching typically involves donor plasma and recipient red blood cells.

a
True
b
False

Crossmatching involves donor red blood cells and recipient plasma. Remember, we are interested in excluding antibodies in the recipient that might react against donor erythrocytes, causing a transfusion reaction. That being said, there is procedure called a minor crossmatch that does indeed examine the interaction between the recipient’s red cells and donor plasma.

True of false: crossmatching is the final phase of compatibility testing in red cell transfusion.

a
True
b
False

Compatibility testing in transfusion medicine includes ABO and Rh D typing of the patient and antibody screening.

Which of the following statements is/are true:

a
The immediate spin (IS) crossmatch is the serologic confirmation of the ABO type
b
The immediate spin (IS) crossmatch is used to test for unexpected RBC antibodies
No. A positive IS crossmatch suggests the presence of an immunoglobulin that has the capacity to bridge RBCs or fix complement (since AHG is not added to the sample). Most frequently, this is an immunoglobulin M (IgM) and is concerning for ABO mismatch.
c
The AHG crossmatch is is the serologic confirmation of the ABO type
d
The AHG crossmatch is used to test for unexpected RBC antibodies