OBJECTIVETo observe the engraftment, survival and graft-versus-host disease (GVHD) after 2 units unrelated cord blood (UCB) transplantation for treatment of adult hematological malignancies.

METHODSAmong twelve patients with hematological malignancies, ten were in stable stage and 2 in advanced stage. Conditioning regimen was Bu/Cy or Cy/TBI in 11 cases, and 1 received nonmyeloablative regimen. Antithymocyte globulin (ATG) was administered in all patients. GVHD prophylaxis consisted of cyclosporine A (CsA), mycophenolate mofetil (MMF) and short course methotrexate (MTX). Each patient received 2 units UCB of HLA mismatched at 0 -2 loci. Median total nucleated cells (TNC) infused was 5.55 x 10(7)/kg [range (2.99 -8.18) x 10(7)/kg].

RESULTSOne patient showed primary graft failure. The other 11 patients showed neutrophil engraftment at a mean time of (21.6 +/- 5.1) days and platelet engraftment at (34.9 +/- 9.5) days. One patient showed secondary graft failure and died of leukemia relapse at 3 months after transplantation. Ten patients (83.3%) gained sustained engraftment. In 9 patients the UBC unit with larger TNC dose predominated engraftment, and only 1 patient showed the unit with smaller TNC predominated (P = 0.011). Acute GVHD was observed in 6 patients, including grade I in 5 and grade II in 1. Limited chronic GVHD was observed in 2 of 10 patients survived more than 100 days. Of the total 12 patients, eight were still alive in event-free status and 3-year event-free survival(EFS) was (66.7 +/- 13.6)%. Of the 10 patients in stable stage at the time of transplantation, the probability of EFS was (70.0 +/- 14.5 )%.

CONCLUSIONSTwo UBC units transplantation with HLA mismatched at 0 - 2 loci is feasible as a treatment modality for adult hematological malignancies, and the unit with larger TNC dose would predominate the engraftment.