A Transient Change of the Blood Group Accompanied by the Decreased Activity of the A transferase in a Case of Acute Myeloid Leukemia

Abstract

A 78-year-old male with hypoplastic acute myeloid leukemia developed a transient change in his blood group. On admission, his red cells agglutinated weakly against anti-A with twenty percent free red cells, although his blood group was essentially A, while his serum reacted with only B red cells. The agglutination titer to Ulex europaeus (anti H) was high and that to Dolichos biflorus (anti A₁) was low compared with the control red cells. Moreover, the A and H antigens were contained in his saliva. Activity of the glycosyl A transferase in his serum was lower than the control on admission, while his red cells were transformed to typical A in the presence of the normal A transferase. In our case, therefore, the modified A of his red cells was probably due to the decreased activity of the A transferase. The similar changes in the blood group examination were observed at the relapse after 10 months remission.