Granulocyte colony-stimulating factor alone at 20 micrograms/kg vs. 10 micrograms/kg for peripheral blood stem cell...

Mobilization of peripheral blood stem cells (PBSC) by granulocyte colony-stimulating factor (G-CSF), at 10 micrograms/kg/day vs. 20 micrograms/kg/day (in 42 and 29 patients, respectively), was compared in children with solid tumors or leukemias. During mobilization, differences were noted in the peak values of CD34+ cells in peripheral blood (PB) in these two groups (median 28 x 10(6)/L for 10 micrograms/kg/day vs. 61 x 10(6)/L for 20 micrograms/kg/day; p = 0.025). Similar numbers of progenitor cells were harvested for the two concentrations of G-CSF. However, similar CD34+ cell levels in the leukapheresis product were obtained after only the third dose of G-CSF at 20 micrograms/kg/day compared with the fourth dose of G-CSF at 10 micrograms/kg/day (1.7 and 1.2 x 10(6) CD34+ cells/kg/one patient's blood volume processed, respectively). Of note is the impact of diagnosis on PB CD34+ cell levels. We conclude that, in children, mobilization with G-CSF at 20 micrograms/kg/day could minimize the duration of priming but not reduce the number of leukaphereses. Thus, the impact on outcome, clinical practice, bed utilization, and health economics is uncertain.