Hematopoietic Graft Detected by a Change in ABO Group

A change in blood group was discovered in a group O boy with acute lymphocytic leukemia. Fifty-six per cent of his red cells were of group AB 6 weeks after he received white cell-rich plasma from a group AB donor with chronic myelogenous leukemia. It is concluded that hematopoietic cells in the peripheral blood of the donor survived and divided in the recipient, and were then rejected 6 weeks after transfusion. Factors favoring the acceptance of the graft, consideration of the type of cell or cells that proliferated, and the relation of this finding to recently published reports of survival of cells containing the Ph¹ chromosome are discussed.