Transfusion of donor buffy coat cells in the treatment of persistent or recurrent malignancy after allogeneic bone marrow transplantation

Background: Patients who experience relapse after allogeneic bone marrow transplantation have a poor prognosis. However, preclinical and clinical data have strongly suggested the existence of an immune-mediated anti-tumor effect of allogeneic bone marrow transplantation. This effect, termed graft-versus-leukemia, may be harnessed purposefully in patients with posttransplant relapses by the administration of immune cells obtained by leukapheresis of the original bone marrow donor. Study Design and Methods: Thirteen patients with persistent or recurrent hematologic malignancy after HLA-matched sibling-donor allogeneic bone marrow transplantation were treated with transfusion of buffy coat cells collected from the original bone marrow donors. Mononuclear cell doses ranged from 1.18 to 4.28 x 10(8) per kg. Alpha-interferon (1.5-3 x 10(6) U/m(2) 3-5x/week) was given to seven patients. Patients were observed for the development of graft-versus-host disease and disease response. Results: Three of five patients with chronic myelogenous leukemia had complete remissions. One of five patients with active acute leukemia attained complete remission. A sixth acute leukemia patient treated with buffy coat transfusion after the induction of remission with chemotherapy relapsed 12 months later. One patient with myeloma had a complete but transient response. A patient with Hodgkin's disease did not respond. Four patients remain in remission 4, 16, 17, and 29 months after attaining complete remission. Graft-versus-host disease occurred in eight patients, including all of those with a complete response. One patient developed transient pancytopenia. Conclusion: The transfusion of donor buffy coat cells has significant anti-tumor activity in patients with relapsed hematologic malignancy after allogeneic bone marrow transplantation. This effect is strongly associated with graft-versus-host disease.