Anti-K14: an Antibody Specificity Associated with the Kell Blood Group System

. The San serum (anti-K14) recognizes a high-frequency red-cell antigen that is related to the Kell blood group system. The antibody reacts with the red cells of all of more than 600 random blood donors, but red cells of Ko phenotype are nonreactive. Cells having null phenotypes in other blood group systems are incompatible. The reactive antigen is thus related to the Kell system, but our investigation has established it to be different from the known high-frequency antigens related to this blood group. The antibody caused mild hemolytic disease of the newborn in two of the proposita's children.