Allogeneic bone marrow transplantation.

Allogeneic bone marrow transplantation (BMT) after high-dose, marrow-ablative chemoradiotherapy has been established as the treatment of choice for various hematologic, neoplastic, and congenital disorders. The most common type of marrow graft is an allogeneic one from a sibling donor who has compatible human leukocyte antigen (HLA). Only 30% of patients requiring allogeneic BMT have an HLA-compatible sibling donor. Over the past few years, marrows from unrelated HLA-compatible donors have been used with increasing frequency and promising outcome in certain hematologic malignancies. Despite the morbidity and mortality associated with this treatment modality, allogeneic BMT may provide a 20% to 90% chance of long-term, disease-free survival to patients with a wide variety of neoplastic and abnormal marrow disorders.