Mobilization of peripheral blood progenitor cells using 16 versus 10 mg/kg/d G-CSF in children with malignancies.

ABSTRACT

Administration of hematopoietic growth factors, with or without chemotherapy, can augment progenitor cell numbers available for collection. The dose of granulocyte colony stimulating factor (G-CSF) used for mobilization of peripheral blood progenitor cells (PBPC) is controversial, and doses between 5 and 32 microg/kg/d have been reported in adults. In order to determine the dose-response effect for G-CSF in mobilizing PBPC in children, we randomized 30 children with malignancies to receive either 16 or 10 microg/kg/d subcutaneously starting on the day after the disease-oriented chemotherapy regimen and continuing until the completion of leukapheresis. Leukapheresis commenced after threshold WBC > 1 x 10(9)/L was achieved and continued until 10 x 10(6) CD34+ cells/kg were obtained or for 6 procedures. Both treatment groups achieved an adequate yield of CD34+ cells with an average of 4 leukapheresis procedures. The numbers of CD34+ cells/kg were 8.3 x 10(6) and 11.7 x 10(6) in patients receiving 16 and 10 microg/kg/d doses of G-CSF, respectively, or 2.1 x 10(6) and 3.7 x 10(6) cells/kg per leukapheresis. The levels of CD34+ cells in peripheral blood had a wide interindividual variation, and were not significantly different after 16 or 10 microg/kg doses of daily G-CSF. We conclude that there is no advantage to using 16 microg/kg/d of G-CSF post-chemotherapy for PBPC mobilization in children.