Donor leukocyte infusion for Japanese patients with relapsed leukemia after allogeneic bone marrow transplantation: indications and dose escalation.

To clarify the role of dose escalation of donor leukocyte infusion (DLI) in the treatment of relapsed leukemia after allogeneic bone marrow transplant (BMT), data from 100 patients were collected from 46 facilities in Japan and analyzed with respect to indications and infused cell dose. Complete remission (CR) was achieved in 11 of 12 (91%) patients with relapsed chronic myelogenous leukemia (CML) in the chronic phase, 3 of 11 (27%) with CML in the acute phase, 8 of 21 (38%) with acute myelogenous leukemia (AML), 6 of 23 (25%) with acute lymphoblastic leukemia (ALL), and 5 of 11 (45%) with myelodysplastic syndrome (MDS). The probability of remaining in CR at 3 years was 82% in CML patients in the chronic phase, but 0% in those with CML in the acute phase, 7% in those with AML, 0% with ALL, and 33% with MDS. Acute graft-versus-host disease (GVHD) (> or = 2) developed in 31 of 89 (34%) patients with human leukocyte antigen identical related donors and was fatal for 7 (7%). A leukocyte dose of 1 x 10(7)/kg of recipient body weight with CML in the chronic phase, 3 x 10(7)/kg of recipient body weight with MDS, and 1 x 10(8)/kg of recipient body weight with acute leukemia appeared to be optimal as an initial dose of DLI. However, the minimal dose of leukocyte developing fatal GVHD was 7 x 10(7)/kg of recipient body weight. These suggest that a relatively small dose of DLI ranging from 1 x 10(7)/kg to 5 x 10(7)/kg of recipient body weight should be administered initially then the infused escalating dose 2 or 3 months later in patients with CML in the chronic phase and MDS. However, a large number of leukocytes around 1 x 10(8)/kg are needed to induce graft versus leukemia effects in patients with acute leukemia despite a 7% fatality in GVHD.