Stem Cell Transplantation for Patients With Graft Failure Following an Allogeneic Transplant, Using Identical or Near Identical Donors and Less Toxic Conditioning With CAMPATH 1H

To assess the safety, feasibility, and rate of donor engraftment for patients with primary or secondary engraftment failure after treatment with fludarabine and CAMPATH 1H used as a preparative regimen for HLA-identical sibling blood stem cell transplantation (SCT). To assess the safety, feasibility, and rate of donor engraftment for patients with primary or secondary engraftment failure after treatment with fludarabine and CAMPATH 1H as a preparative regimen for matched unrelated or single antigen mismatched family donor marrow transplantation.