Allogeneic Peripheral Blood-Stem Cell Transplantation in Children and Young Adults with Hematologic Malignancies

Abstract

We assessed the feasibility and hematopoietic efficacy of allogeneic peripheral blood-stem cell transplantation (allo-PBSCT) in patients with hematologic malignancies, and the safety of normal donors who received recombinant human granulocyte colony-stimulating factor (G-CSF) and underwent apheresis. HLA-matched sibling normal donors aged from 2 to 30 years (median ; 8 years) received 10μg/kg/day G-CSF for 5 days and underwent apheresis. Harvested cells were cryopreserved. Patients with ALL (n=2), AML (n=3) and MDS (n=2) aged from 1 to 27 years (median; 10 years) received busulfan (16 mg/kg) and melphalan (210 mg/m²) for myeloablation. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin A and methylpred-nisolone. All of the donors tolerated G-CSF administration and harvest procedures. All of the patients showedprompt engraftment with median time for recovery of an absolute neutrophil counts (ANC) above 0.5 × 10⁹/l of 10 days (range; 9-11) and an unsupported platelet counts above 50 × 10⁹/l of 14 days (range; 10-35). Grade 2-4 acute GVHD was observed only in one patient. One patient died from interstitial pneumonia, and another died from veno-occlusive disease of the liver (VOD). Chronic GVHD occurred in three patients. No relapse was observed during the follow-up period of 218-460 days (median ; 373) following transplant. We conclude that mobilization and harvesting of PBSC are technically feasible and acceptable for healthy childhood donors. Hematopoietic reconstitution after transplantation of allogeneic PBSC is reliable and prompt. Although the incidence of acute GVHD may be comparable to allo-BMT, chronic GVHD remains a problem after allogeneic PBSCT. However, chronic GVHD might contribute to the low incidence of relapse.