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 marr ow transplantation have a poor prognosis. However, preclinical and cli nical data have strongly suggested the existence of an immune-mediated anti-tumor effect of allogeneic bone marrow transplantation. This eff ect, termed graft-versus-leukemia, may be harnessed purposefully in pa tients with posttransplant relapses by the administration of immune ce lls obtained by leukapheresis of the original bone marrow donor. Study Design and Methods: Thirteen patients with persistent or recurrent he matologic malignancy after HLA-matched sibling-donor allogeneic bone m arrow transplantation were treated with transfusion of buffy coat cell s collected from the original bone marrow donors. Mononuclear cell dos es 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 obs erved for the development of graft-versus-host disease and disease res ponse. Results: Three of five patients with chronic myelogenous leukem ia had complete remissions. One of five patients with active acute leu kemia attained complete remission. A sixth acute leukemia patient trea ted 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 month s after attaining complete remission. Graft-versus-host disease occurr ed in eight patients, including all of those with a complete response. One patient developed transient pancytopenia. Conclusion: The transfu sion of donor buffy coat cells has significant anti-tumor activity in patients with relapsed hematologic malignancy after allogeneic bone ma rrow transplantation. This effect is strongly associated with graft-ve rsus-host disease.