ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR LEUKEMIA WITH MARROW GRAFTS TREATED BY COUNTERFLOW CENTRIFUGATION

Eighty consecutive patients were transplanted with human leukocyte ant igen (HLA)-identical sibling marrow for acute myelogenous leukemia (AM L, N = 29), acute lymphoid leukemia (ALL, N = 23), or chronic myelogen ous leukemia (CML, N = 28). Donor marrow was depleted of lymphocytes u sing counterflow centrifugation. Median age of the recipients was 31 y ears. Pretransplant conditioning consisted of cyclophosphamide and fra ctionated total body irradiation (TBI). Graft failure occurred in 4 of 77 evaluable patients (5%). The probability of acute graft-versus-hos t disease (GVHD) greater-than-or-equal-to grade 2 at day 100 after tra nsplantation was 15%. The projected 3-year estimate of extensive chron ic GVHD was 12%. The projected 3-year probability of relapse was 30% i n transplants for AML in first complete remission (CR1), 35% after tra nsplantation for ALL in CR1, and 38% after transplantation for CML in first chronic phase (CP1). The projected 3-year probability of leukemi a-free survival (LFS) was 56% after transplantation for AML-CR1, 42% i n patients transplanted for ALL-CR1, and 49% after transplantation for CML-CP1. The chance of relapse was significantly reduced in a cohort of 72 standard risk patients conditioned with a regimen intensified by the addition of anthracyclines. This resulted in DFS at 4 years after BMT of 63% compared to 39% in a historical control group. Enrichment of the donor marrow with NK-cells did not increase the incidence of GV HD, but did neither decrease the relapse rate after BMT. In bone marro w transplantation for leukemia, counterflow centrifugation is a useful technique for the prevention of GVHD. Further efforts should be made to reduce relapse-rate, particularly in high risk patients.