Donor leukocyte transfusions and discontinuation of immunosuppressants to achieve an initial remission after allogeneic bone marrow transplantation in a patient with primary refractory acute leukemia.

We present a female patient who received an allogeneic bone marrow transplantation for primary refractory Philadelphia-positive acute biphenotypic leukemia. Since leukemic blasts were persistently present in peripheral blood and bone marrow, in spite of the evidence for engraftment of male donor hematopoiesis, we performed donor leukocyte transfusions and discontinued immunosuppression. An initial complete remission was obtained 15 weeks after allogeneic bone marrow transplantation, and lasted for 24 weeks. We concluded that the prominent mechanism for the eradication of the refractory leukemic clone in the patient was the graft-versus-leukemia effect.