Stem cell mobilization by G-CSF in solid and hematological malignancies: single daily dose is better than split dose in obese patients.

In the past, variable results were reported for single daily and two divided daily doses of granulocyte colony-stimulating factor (G-CSF) in stem cell collection where no study exists investigating the effect of body mass index (BMI) on mobilization. The numbers of CD34(+) cells collected were compared in 86 patients with solid or hematological malignancies receiving either single daily (14 mug/kg/day) G-CSF (filgrastim) as group I (n=36) or two divided doses of G-CSF daily (2 x 7 mug/kg/day) as group II (n = 50). Both groups were divided into subgroups according to their BMI as group a (BMI 25 kg/m(2)). Two groups were similar in terms of BMI, gender, and disease characteristics. All patients have received G-CSF as a single or two divided doses subcutaneously and aphereses have been done on the 5th day. No significant difference in numbers of CD34(+) cells between groups Ia and Ib, groups IIa and IIb, and groups Ia and IIa was found. On the other hand, the mean ratio and the number of CD34(+) cells in group Ib were significantly higher than those of group IIb (0.58 +/- 0.06% vs. 0.37 +/- 0.26%, P = 0.01 and 3.67 +/- 0.65 x 10(4)/kg/ml vs. 1.92 +/- 0.37 x 10(4)/kg/ml, P= 0.02). In conclusion, in patients with BMI >25 kg/m(2), once daily G-CSF compared to split dose administration induces a greater number of CD34(+) stem cell mobilization, which suggests the presence of a different pharmacokinetics in obese patients.