Allogeneic transplantation of peripheral blood progenitor cells in children: Experience of two pediatric centers

Between February 1995 and August 1997, 11 children (eight males, three females) aged 4-16 years (median 7 years) underwent allogeneic PBPC transplantation for treatment of hematological disorders. Seven patients with acute leukemia (n = 5 ALL, n = 1 AML) or lymphoma (n = 1) received primary allogeneic PBPC transplantation, four patients received a second allotransplantation for graft failure (n = 1 AML, n = 1 sickle cell anemia) or disease recurrence (n = 1 ALL, n = 1 MDS). Five donors were HLA-identical siblings, five were 0-1 antigen mismatched family members and one was a matched unrelated donor. Donors received G-CSF 10-12 μg/kg/day for 3-7 days, and underwent one or two leukaphereses. The median cell yield per donor expressed per kg of recipient body weight was as follows: mononucleated cells 10.8 x 10⁸/kg (range 4.7-21.2); CD34⁺ cells 8.6 x 10⁶/kg (range 3.2-22); CD3⁺ cells 3.7 x 10⁸/kg (range 2.7-7.5). All patients achieved an ANC > 0.5 x 10⁹/l after a median of 12 days (11-18). An unsupported platelet count > 50 x 10⁹/l was reached 15 days (13-21) after PBPC transplantation; four patients failed to reach this threshold. Acute GVHD (aGVHD) grades II to IV occurred in eight (73%) patients: seven of them experienced grade III-IV aGVHD. Seven patients evaluable for chronic GVHD (cGVHD) were scored as absent in five, limited in one and extensive in one patient. As of September 1997, six patients (55%) were alive between 60 and 938 days posttransplant (median follow-up 274 days); four patients with malignancy were alive in CR after primary allotransplantation, two patients were alive after a second PBPC transplant. Five patients have died with the main causes of death being aGVHD (n = 3), ARDS (n = 1), relapse of the underlying disease (n = 1). In conclusion, despite the limited number of patients, these preliminary results indicate that PBPC may be considered as an alternative to bone marrow for allografting also in children.