Transplantation of HL-A Identical Allogeneic Bone Marrow to a Patient With Acute Lymphocytic Leukemia

An 8-year-old boy with acute lymphocytic leukemia, no longer responsive to conventional chemotherapy after 2 years, was successfully grafted with bone marrow from his HL-A genotypically identical 10-year-old sister. Prior to transplantation, he had received 141 blood component transfusions and had become sensitized to histocompatibility antigens (HL-A), as demonstrated by the presence of circulating lymphocytotoxic antibodies. Except for the occurrence of a possible mild graft-versus-host-reaction and a documented cytomegalovirus infection, the patient remained clinically well until full return of his leukemia 91 days after the transplant. This case demonstrates that bone marrow transplantation can be accomplished between HL-A identical siblings even though the recipient may have been previously sensitized to other HL-A antigens by earlier transfusion. Allogenic bone marrow transplantation offers the opportunity for remissions in patients with leukemia unresponsive to conventional drug therapy.