Treatment of Bone Marrow to Prevent Graft-Versus-Host Disease in Patients With Acute or Chronic Leukemia Undergoing Bone Marrow Transplantation

DISEASE CHARACTERISTICS: Diagnosis of one of the following: Acute myelogenous leukemia (AML) or acute lymphocytic leukemia (ALL) in first early relapse, second remission, or subsequent remission AML in first complete remission with one of the following adverse features: Antecedent hematologic disorder such as myelodysplasia AML resulting from prior chemotherapy or radiotherapy More than 1 course of induction chemotherapy to achieve remission or adverse cytogenetics such as Philadelphia chromosome 9:22, +8, +11; abnormal 12p; or deletions of chromosomes 5, 7, or 20 (3:3) ALL in first complete remission with poor risk cytogenetics such as Philadelphia chromosome 9:22, 8:14, or 4:11 OR WBC greater than 100,000/mm3 OR Time to achieve complete remission more than 4 weeks Chronic myelogenous leukemia in chronic or accelerated phase Myelodysplastic syndromes Refractory anemia with excess blasts (RAEB) OR RAEB in transformation Unrelated bone marrow donor available If matched at 6 of 6 HLA-A, -B, and -DR loci, patient must be 12 to 50 years If matched at 5 of 6 loci, patient must be 12 to 35 years No matched sibling donor available No uncontrolled CNS leukemia PATIENT CHARACTERISTICS: Age: See Disease Characteristics 12 to 50 Performance status: Karnofsky 70-100% Life expectancy: At least 12 weeks Hematopoietic: See Disease Characteristics Hepatic: Bilirubin less than 2.5 times upper limit of normal (ULN) SGOT or SGPT less than 2.5 times ULN Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: LVEF greater than 50% without medication Pulmonary: DLCO and FVC at least 50% predicted Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No other serious medical illness No uncontrolled diabetes mellitus No uncontrolled and/or active infection HIV negative PRIOR CONCURRENT THERAPY: Biologic therapy: At least 3 weeks since prior immunotherapy and recovered At least 1 year since prior autologous transplantation No prior allogeneic transplantation Chemotherapy: See Disease Characteristics At least 3 weeks since prior chemotherapy (except hydroxyurea) and recovered Endocrine therapy: At least 3 weeks since prior hormonal therapy and recovered Radiotherapy: See Disease Characteristics At least 3 weeks since prior radiotherapy and recovered No prior radiotherapy at doses that would preclude study Surgery: Not specified