UNRELATED DONOR MARROW TRANSPLANTATION FOR CHRONIC MYELOGENOUS LEUKEMIA

Between January 1989 and July 1995 the search for an unrelated donor ( UD) was started for 379 consecutive Italian patients with Philadelphia positive (Ph+) chronic myelogenous leukaemia (CML). 89 (23%)were tran splanted. The overall probability of transplant before and after Decem ber 1991 was 16% and 49%, respectively (P=0.0001), and average interva l between search activation and graft was 23 months and 13 months, res pectively (P=0.0001). Disease-free survival (DFS following 60 consecut ive transplants performed before February 1996 was 41.5% at 48 months and was 64% for patients grafted after January 1993. In univariate ana lysis, ave variables had a favourable effect on DFS: year of bone marr ow transplantation (BMT) after 1993 (P=0.0002). HLA-DRB1 donor/recipie nt (D/R) match (P=0.0006), total body irradiation (TBI) containing reg imen (P=0.0006). graft-versus-host disease (GVHD)) prophylaxis includi ng 'early' cyclosporin before the transplant, and a marrow cell dose > 3 x 10(8)/kg of recipient body weight (P=0.04). Multivariate analysis confirmed that HLA identity (P=0.006), TBI-containing regimen (P=0.00 01) and 'early cyclosporin' (P=0.04) were associated with higher DFS, Transplant-related mortality (TRM) was 67% in patients grafted before January 1993 and 30% in patients grafted subsequently (P = 0.002), Mul tivariate analysis confirmed DRB1 identity (P=0.03) and TBI-containing regimen (P = 0.0005) to be independent factors predictive of low TRM, This suggests that the outcome of patients transplanted from an HLA D RB1 matched donor, after a TBI-containing preparative regimen, is simi lar to results recently reported in patients transplanted from gene-id entical siblings. These results indicate that the search should be ini tiated at diagnosis for patients <45 rears of age and UD BMT should be considered early in the disease course for those with an available DR B1-matched unrelated donor.