Recent advances in bone marrow transplantation.

The major barriers to successful bone marrow transplantation (BMT) are graft-versus-host disease (GVHD), infection, rejection and relapse. The combination of methotrexate and cyclosporin is significantly better than either alone in controlling GVHD. Removal of T cells from donor marrow prior to BMT has also decreased GVHD significantly, but a 5-10% rejection rate occurs and an increased relapse risk is being reported by some centres. Cyclosporin is valuable in the treatment of both acute and chronic GVHD. Interstitial pneumonitis due to cytomegalovirus (CMV) is a major cause of mortality. Protection can be provided with CMV hyperimmune globulin and also by the avoidance of blood donors who are CMV antibody positive. Fractionated total body irradiation is associated with decreased toxicity compared to single dose. There is a 75% 4 year disease-free survival following BMT for acute non-lymphoblastic leukemia in first remission, a 50% survival for acute lymphoblastic leukemia in second remission and an 88% survival for chronic myeloid leukemia in chronic phase. BMT for beta-thalassaemia major in young patients without organ dysfunction cures 80% of patients and identical results are achieved for severe aplastic anaemia when BMT is undertaken prior to blood product transfusion.