Allogeneic bone marrow transplantation in the treatment of hematologic diseases

The current use of allogeneic bone marrow transplantation in various hematologic diseases is reviewed. Bone marrow transplantation (BMT) involves infusion of bone marrow from a suitable donor into a properly conditioned recipient. Most BMT is allogeneic, in which the donor is genetically dissimilar but shares some common tissue antigens with the recipient. Almost all patients undergoing allogeneic BMT must be "prepared" with high-dose cyclophosphamide to prevent graft rejection. Most patients with hematologic malignancy also receive total body irradiation to eradicate malignant cells located in areas inaccessible to the systemic circulation. Bone marrow transplantation is the treatment of choice for severe aplastic anemia. In acute myelogenous leukemia, the best results are observed in young patients undergoing BMT in first remission. In acute lymphoblastic leukemia, BMT is usually reserved for patients in second or subsequent remission. Early results are promising in patients with chronic myelogenous leukemia who receive BMT before the accelerated phase or blast crisis of this disease. Allogeneic BMT offers an opportunity for cure in some patients with relapses of Hodgkin's disease or those with certain subtypes of non-Hodgkin's lymphoma. Other diseases for which BMT has been used include severe combined immune deficiency disease, Fanconi's anemia, and multiple myeloma. Complications of BMT include graft failure or rejection, acute and chronic graft-versus-host disease, and infectious complications; late complications, such as restrictive and obstructive pulmonary disease, cataracts, sterility, and secondary malignancies, may also occur. Bone marrow transplantation has become an important treatment for many hematologic diseases, but it will probably remain a treatment reserved for only a few highly specialized centers. If morbidity and mortality caused by transplant-related complications can be reduced, BMT may be offered to older patients and those without HLA-identical sibling donors.