Donor Lymphocyte Infusion for Relapsed Hematological Malignancies after Unrelated Allogeneic Bone Marrow Transplantation Facilitated by the Japan Marrow Donor Program.

To evaluate the safety and efficacy of donor lymphocyte infusion (DLI), we retrospectively analyzed 414 recipients who received unrelated DLI (UDLI) for the treatment of relapsed hematological malignancy after unrelated bone marrow transplantation (BMT). UDLI was administered for acute myelogenous leukemia (n = 184), myelodysplastic syndrome (n = 69), acute lymphocytic leukemia (n = 57), chronic myelogenous leukemia (CML, n = 36), lymphoid neoplasms (n = 38), adult T cell leukemia/lymphoma (n = 18), and multiple myeloma (n = 12). Sixty-five patients (16%) were in cytogenetic/molecular relapse and 349 (84%) were in hematological relapse after BMT. In total, 266 out of 414 (64%) patients received chemotherapy and/or molecular-targeted agents in combination with UDLI. The median time from BMT to UDLI was 244 days. The median number of infused CD3+ cells was 3.51 × 107 /kg. Response and survival rates were evaluated at 100 days after UDLI. Complete response was obtained in 37 (57%) of 65 patients with cytogenetic/molecular relapse and in 69 (20%) of 349 patients with hematological relapse (P < .001). Two hundred forty-seven patients (60%) were alive, whereas 110 (26%) had died because of disease progression, 26 (6%) because of infections, 12 (3%) because of graft-versus-host disease (GVHD), and 13 (3%) because of organ failure. Multivariate analysis identified molecular/cytogenetic relapse, GVHD after UDLI, and CML but not combination with chemotherapy as significant prognostic factors. These results indicate that UDLI may have efficacy in relapsed patients with CML, low tumor burden, or occurrence of GVHD after UDLI.