OBJECTIVESTo investigate the engraftment, survival and graft-versus host disease (GVHD) after transplantation of unrelated cord blood for the treatment of childhood and adult hematological malignancies.

METHODSSeventeen patients (13 children and 4 adults) with hematological malignancies were enrolled in this study. Twelve patients were transplanted with one unit and 5 with 2 units of cord blood. There were HLA-matched in 6 and HLA-mismatched at 1 approximately 2 loci in 11 patients. Ten patients were transplanted at stable status, 7 at advanced stage of leukemia. Conditioning regimens were BU/CY for 13 and CY/TBI for 3 patients. Most patients received additional ATG at a dose of 15 approximately 20 mg x kg(-1) x d(-1) for 3 days. CsA, mycophenolate mofetil (MMF) and methylprednisolone were used for GVHD prophylaxis.

RESULTSFourteen patients survived more than 40 days after transplantation were evaluated for engraftment. At day 60 after UCBT, 86% and 71% of the patients showed neutrophil and platelet engraftment, respectively. The time for an absolute neutrophil count > or = 0.5 x 10(9)/L was (21.0 +/- 1.3) days and platelet > or = 20 x 10(9)/L was (39.0 +/- 10.3) days. Four patients developed grade II acute GVHD and 2 chronic GVHD. Of the 17 patients, 11 were still alive and 8 of them were in event-free status. For the 10 patients transplanted at stable status, 2 year overall survival is 90%, and event-free survival (EFS) 70%. However, for the 7 patients transplanted at advanced stage of leukemia, only 2 survived without relapse. Of the 4 adult patients, 2 had sustained engraftment and survived for 18 and 14 months, respectively.

CONCLUSIONSHLA-matched or 1 approximately 2 loci-mismatched UCBT is a feasible procedure to cure a significant proportion of children or adults with leukemia, especially if performed in a favourable phase of disease. Two units of CBT can be used for adult patients if the cell number of one unit is not enough.