Pilot Study of Hematopoietic Stem Cell Transplantation From Two Matched Sibling Donors in Treating Patients With Poor Prognosis Acute Leukemia and Advanced Lymphoproliferative Malignancies

Inclusion Criteria: 1. Age 18 years or older 2. Patients with refractory or relapsed acute leukemia unable to receive myeloablative conditioning. 3. Patients with refractory or relapsed acute leukemia able to receive myeloablative conditioning but with the following factors: AML- 2 or more of the following: duration of CR1 \< 6 months, poor cytogenetics, circulating blasts, karnofsky \< 90. ALL- age \> 40 or second and additional relapse, or 2 or more of the following: BM blasts \> 25%, age 18-39,first refractory relapse, donor CMV positive. 4. Patients with 2 matched siblings and donor age \> 18 years old. 5. Patients with advanced multiple myeloma with life expectancy of less than 6 months with standard therapy or transplantation. 6. Patients with advanced lymphoma with life expectancy of less than 6 months with standard therapy or transplantation. Exclusion Criteria: 1. Patient age \< 18 years. 2. Donor age \< 18 years. 3. Patients in remission or not fulfilling above disease criteria -