UNRELATED VOLUNTEER BONE-MARROW TRANSPLANTATION - INITIAL EXPERIENCE AT ST-VINCENTS-HOSPITAL, SYDNEY

Background. Only 30% of patients with leukaemia have an HLA-compatible family member able to act as a marrow donor. The recent development o f volunteer bone marrow donor registries has supplied HLA-matched dono rs for a number of such individuals. Aims: To define the problem and o utcome of the first cohort of patients given HLA-matched unrelated vol unteer bone marrow transplants at St Vincent's Hospital, Sydney. Metho ds: Post transplant outcome of patients with advanced leukaemia given HLA-identical unrelated donor marrow transplants was compared to that of patients transplanted concurrently from HLA-identical sibling donor s, in terms of survival, leukaemia-free survival, incidence and severi ty of acute graft-versus-host disease (GVHD), duration of neutropenia, incidence of infection and duration of transplant hospitalisation. Re sults. Sixteen patients with advanced leukaemia and without a histocom patible family member donor received unrelated donor bone marrow trans plants. Actuarial survival at two years post transplant was 30%. Actua rial survival of 23 recipients of HLA-identical sibling bone marrow tr ansplants with advanced leukaemia transplanted during the same time pe riod was 17% (not significant). Actuarial disease free survival at two years was 30% and 13% respectively. Three of five long term survivors of the unrelated transplants had chronic myeloid leukaemia in blastic transformation at the time of transplant; thus blastic transformation should not preclude consideration of unrelated marrow transplantation . Recipients of unrelated allografts had a higher incidence of acute G VHD which occurred earlier and with greater severity than in recipient s of sibling allografts, a longer duration of post transplant neutrope nia (24 days to reach 0.5 x 10(9)/L versus 19.5, p = 0.07), a higher f requency of infection in the first 100 days post transplant (p = 0.000 4) and a longer duration of transplant hospitalisation (p = 0.04). Tra nsplant-related complications were the commonest cause of death in the unrelated donor recipients, while leukaemic recurrence was the common est single cause of death in the HLA-identical sibling recipients. Imp rovements are needed in prophylaxis of infection and in prevention and treatment of acute GVHD in recipients of unrelated donor transplants. Nevertheless, this modality provides curative treatment for patients with otherwise incurable haematological malignancies and should no lon ger be considered experimental.