During the last 16 years, clinical bone marrow transplantation (BMT) has become an important treatment modality for life-threatening hematologic and selected genetic disorders. The cumulative number of transplants performed since 1969 has passed 6,500 and continues to grow at an exponential rate. Whereas BMT was initially limited to patients with end-stage leukemia or bone marrow failure, it is now widely used early during the clinical course of a variety of diseases. Initially, when only patients who were in the terminal stages of their disease were treated, survival results were on the order of 10%-20%. Now survival rates are greatly improved, ranging from 50% -80%. The basis for this remarkable improvement was the step from transplantation of patients in refractory stages to better candidates who were transplanted during remission (patients with leukemia) or before they became sensitized through blood transfusions (patients with bone marrow failure). Table I lists the kind of disorders treated by bone marrow ablation with high doses of total body irradiation and chemotherapy followed by infusion of bone marrow from histocompatible sibling donors. They range from hematologic malignancies to bone marrow failure syndromes and genetic disorders.Disease-free survival after bone marrow transplantation for the various leukemias depends largely on two prognostic factors, namely age and remission status of the BMT recipient at the time of marrow transplantation. The data in Table I1 provide information regarding outcome of BMT in relation to type and remission status of acute nonlymphoblastic leukemia (ANLL), acute lymphoblastic leukemia (ALL) and chronic granulocytic leukemia (CGL).
