Review: the Kell, Duffy, and Kidd blood group systems.

After the discovery (over 50 years ago) that the IAT could be applied to the detection of antibodies to blood group antigens, there was a rapid increase in the identification of alloantibodies that caused transfusion reactions or HDN. After Rh, antibodies in the Kell, Duffy, and Kidd blood group systems were the next in clinically significant antibodies to be revealed. Much of what has been learned about these blood groups since the journal Immunohematology issued its first edition has to do with the proteins, the genes, and the molecular basis for the antigens. What has not changed is that, after ABO and Rh, antibodies to antigens in these three systems are still the most clinically significant. They will form the basis of this review.