Reduced-Intensity Regimen Before Allogeneic Transplant for Patients With Relapsed Non-Hodgkin's or Hodgkin's Lymphoma

OBJECTIVES: * Determine the rate of stable engraftment of donor cells in patients with relapsed non-Hodgkin's or Hodgkin's lymphoma treated with a reduced toxicity conditioning regimen followed by allogeneic (sibling or unrelated) bone marrow transplantation. * Determine the extent and duration of acute and chronic graft-versus-host disease in patients treated with this regimen. * Determine the 100-day overall survival and long-term progression-free survival of patients treated with this regimen. * Evaluate the feasibility of collection of molecular chimerism studies at baseline, days 30, 100, 6 months and one and two years and at relapse. OUTLINE: This is a multicenter study. * Conditioning regimen: Patients undergo extracorporeal photopheresis using methoxsalen and UV light on 2 consecutive days between days -7 to -4. Patients receive pentostatin intravenously (IV) continuously on days -3 to -2 and undergo total body irradiation on day -1. * Allogeneic bone marrow transplantation: Patients undergo infusion of allogeneic bone marrow or stem cells on day 0. * Graft-versus-host disease prophylaxis: Patients receive oral or IV cyclosporine beginning on day -1 and continuing until 6 months after transplantation, oral mycofenolate mofetil beginning on day 100 and continuing for 1 year, and methotrexate IV on days 1 and 3. Patients are followed at day 100, every 3 months for 1 year, every 6 months for 2 years, and then annually for 2 years. PROJECTED ACCRUAL: A total of 36 patients will be accrued for this study within 1.8 years.