Antibody screening

All individuals receiving blood products must also undergo an antibody screen which detects common alloantibodies in the patient’s plasma which may react with transfused blood containing the particular antigen against which the alloantibody is directed.
Patients having received multiple transfusions in the past or who have been pregnant are at an increased risk of having these alloantibodies in their plasma because of increased opportunity of sensitization to foreign antigen.
In the antibody screen, the patient’s plasma is mixed with a number of laboratory Group O cells with known common red cell antigens. Using the IAT and observing for agglutination, this method allows for the detection of most unexpected antibodies to the common red cell antigens (ie. Kell, Duffy, Kidd, Lewis, etc.).