The Clinical Research of Umbilical Cord Blood Transplantation for Children with Leukemia or Whom with Beta-Thalassemia.

Objective To evaluate the clinical efficacy and complications of related (RD) umbilical cord blood transplantation (UCBT) or unrelated (UD) UCBT for children with leukemia or whom with b-thalassemia (TM).

Methods Ten patients with TM received RD-UCBT (group 1), while another 10 patients with TM had UD-UCBT (group 2).13 patients with leukemia (4 high risk ALL and 9 AML) were transplanted from UD-UCB (group3). Of 7 were HLA-identical, a patient was a loci-mismatched and two of them were half matched in group 1. Meanwhile, in the group2, three of ten patients were HLA matched, six was a loci-mismatched and one received double unites of UD-UCB that was from HLA matched to a loci-mismatched. Furthermore, ten of 13 patients were one loci-mismatched in group 3. Two were two loci-mismatched and one received double unites of UD-UCB from HLA matched to a loci-mismatched in the group. The conditioning regimen was consisted of busulfan (Bu) 14–20 mg /kg, cyclophosphages(Cy) 120–200 mg /kg and horse antithymocyte globulin (ATG)90 mg /kg or rabbit ATG 25 mg /kg for all TM patients. Of them, 6 also received melphalan (Melph) 90 mg /m². Four patients had fludarabine (Flu) 150 mg /m². Three combined Flu with thiotepa (TT) 6 mg /kg. Five used Flu, TT and TBI together. In the group of patients with leukemia (group 3), the regimen was divided into two branches: (1) Non-TBI regimen: the regimen mainly focused on 10 patients with leukemia in the CR phase except a patient was too young although him in the NR phase, which was consisted of Bu, Cy, ATG and Flu. A patient added high dose Ara-C. One had IDA, and 3 Melph. (2). Accompanying with TBI regimen. Only had two patients who were in the phase of NR used this regimen. The dose of TBI was 7.5 Gy and 6.5 Gy respectively. The patients received the nucleated cells 7.5 (3.4–19.4)’10⁷/kg, CD³⁴ cell 4.5 (0.6–11.7) ’10⁵/kg, CFU-GM 1.1 (0.2–23) ’10⁵/kg in three groups.

Result: The engraftment occurred 7 in 10 at the group 1. One patient developed acute GVHD grade III. Two patients rejected 2 months post RD-UCBT. The following up was from 34–69 months in the group and 4 cases remained in the EFS. However, only 3 out of 10 were engraftment in the group 2. The others all were antologous reconstitution in the failure patients. One developed acute GVHD grade II in the group 2. The following up was from 3 months to 43 months in the group. Two cases kept EFS but one died of IP at the 6 months post transplantation. 11 out of 13 patients engrafted in the group 3. Nine patients were EFS post transplantation and the time of following up was from 4 to 37 months in the group. One developed severe acute GVHD and 3 had extensive chronic GVHD.