SURVIVAL AFTER ABO-INCOMPATIBLE ALLOGENEIC BONE-MARROW TRANSPLANT AFTER A PREPARATIVE REGIMEN OF BUSULFAN AND CYCLOPHOSPHAMIDE

The use of an ABO-incompatible donor for BMT after total body irradiat ion (TBI) has no adverse effect on engraftment, incidence of GVHD or s urvival when donor erythrocytes and plasma are depleted from the infus ed marrow, The outcome of ABO-incompatible BMT following a non-TBI-con taining preparative regimen has not been as well studied, We therefore performed a retrospective review of consecutive patients undergoing a llogeneic BMT for myeloid leukemia after treatment with high-dose busu lfan and cyclophosphamide (BUCY) between January 1984 and January 1993 . Of the 199 evaluable patients, 100 had AML or myelodysplastic syndro me, 30 of which were ABO-incompatible, and 99 had CML, 35 of which wer e ABO-incompatible, All patients undergoing transplant received erythr ocyte and plasma-depleted marrow but 14 major ABO-incompatible patient s also underwent plasma exchange before transplant, T cell-depletion a nd purging techniques were not employed, All records were reviewed for prognostic factors including patient age, sex, diagnosis, remission s tatus at the time of transplant, and incidence and severity of acute a nd chronic GVHD. Compatible and incompatible patients with myeloid leu kemia did not differ with respect to age, sex, remission status of dis ease at the time of transplant or incidence of GVHD. Survival between ABO-compatible and incompatible BMT patients with AML did not differ s ignificantly, but estimated 4-year relapse-free survival in CML is 69% for incompatible and 38% for compatible patients (P = 0.04) resulting in an improvement in overall survival (P = 0.05) in ABO-incompatible transplants at a median follow-up of 44 months, Multivariate analysis identified ABO incompatibility as a favorable prognostic factor for re lapse-free and overall survival in both acute and chronic myeloid leuk emia, We conclude that BUCY followed by allogeneic ABO-incompatible BM T is not associated with increased GVHD and may improve relapse-free s urvival in myeloid leukemia in general and CML in particular