Red Blood Cell (RBC) Antigen Typing: Jka/Jkb

Typing paternal RBCs for antigens that correspond to maternal antibody may aid in the prediction of hemolytic disease of the fetus and newborn. Red cell antigen typing may also be indicated for bone marrow, tissue, organ, or blood donors prior to donation. Testing a prenatal patient for red cell antigens is generally not indicated. The occurrence of the Jka antigen is 77% in Caucasians, 92% in Blacks, and 72% in Asians. Anti-Jka can cause mild to moderate (rare) hemolytic disease of the fetus and newborn. The occurrence of the Jkb antigen is 74% in Caucasians, 49% in Blacks, and 76% in Asians. Anti-Jkb can cause rare, mild hemolytic disease of the fetus and newborn.