Pentostatin and Lymphocyte Infusion in Preventing Graft Rejection in Patients Who Have Undergone Donor Stem Cell Transplant

Inclusion Criteria: * Patients having received a preceding allogeneic transplantation from either a human leukocyte antigen (HLA)-matched related or unrelated donor are eligible for this protocol * Related donor: HLA genotypically identical at least at one haplotype and may be phenotypically or genotypically identical at the allele level at HLA A, B, C, DRB1, and DQB1 * Unrelated donor who are prospectively: * Matched for HLA-A, B, C, DRB1 and DQB1 by high resolution typing; OR * Only a single allele disparity will be allowed for HLA-A, B, or C as defined by high resolution typing * Patients with less than 50% donor CD3 peripheral blood chimerism on two separate, consecutive evaluations; the two evaluations must be at least 14 days apart OR patients with absolute decreases of donor CD3 peripheral blood chimerism of \>= 20% if the second test shows \< 50% donor CD3 cells; the two evaluations must be at least 14 days apart * Patients with evidence of disease are only eligible if the disease is stable (or persistent) in comparison to the status prior to transplantation * Patients must be tapered off systemic steroids to a dosage of less than or equal to 0.25 mg/kg/day * Patients must have persistent donor CD3 cells (\>= 5% donor CD3 cells by a deoxyribonucleic acid \[DNA\]-based assay that compares the profile of amplified fragment length polymorphisms \[ampFLP\] \[or fluorescent in situ hybridization (FISH) studies or variable number of tandem repeats (VNTR)\]) *…