Mobilization of peripheral blood stem cells in children using G-CSF after carboplatin containing myelosuppressive chemotherapy

PURPOSE: Peripheral blood stem cell (PBSC) apheresis provides an alternativ e to autologous marrow harvest as a source of hematologic stem cells for tr ansplantation in children with solid tumors. PATIENTS AND METHODS: Eight ch ildren with metastatic or recurrent solid tumors underwent 27 apheresis pro cedures. Recovery from myelosuppressive chemotherapy occurred without conti nuous daily growth factor support prior to mobilization. Granulocyte colony stimulating factor (G-CSF) at 16 mu gs/kg/day was used to increase stem ce lls in the peripheral circulation. CD 34 positive cells, mononuclear cells (MNC), and CFU-GM were measured in the apheresis products. Prior chemothera py was examined as a clinical factor that affected PBSC yield. RESULTS: A s ignificant correlation was found between CD 34(+)/kg and CFU-GM/kg of the p roducts (r = 0.758, P < 0.001). Patients receiving cumulative doses of carb oplatin over 1,600 mg/m(2) produced adequate MNC (1 x 10(8)/kg) but yielded significantly less CD 34(+) cells or CFU-GM than those patients receiving less carboplatin. Prior doses of etoposide and ifosfamide did not effect PB SC yield. CONCLUSIONS: The mobilization technique was well tolerated, and, the products obtained produced trilineage engraftment in the patients that underwent peripheral blood stem cell transplantation. Peripheral blood stem cell apheresis in children can be optimized by selection of appropriate ca ndidates and mobilization with G-CSF after an absence of hematopoietic grow th factor support. J. Clin. Apheresis 13:146-154, 1998. (C) 1998 Wiley-Liss , Inc.