Efficacy of further attempts to mobilize CD34+peripheral stem cells with alternative procedures after primary failure

19 patients who failed the target collection of at least 2.5 x 10(6) CD34cells/kg underwent further mobilization procedures either with granulocyte- colony-stimulating factor (G-CSF) alone after failure to chemotherapy plus G-CSF (group 1), or with chemotherapy plus G-CSF (group 2), or with high-do se G-CSF (24 mu g/kg) alone (group 3) after failure to respond to standard dose of G-CSF(10 mu g/kg) alone. In all groups, an increase in median CD34 cell yield could be observed following alternative procedures (1.1- to 1.9 x 10(6) kg; p = 0.02). The highest increase in CD34+ cell harvest was achi eved in group 1 (0.85 to 2.2 x 10(6) kg), followed by group 2 (1.2 to 1.7) and group 3 (1.0 to 1.4), but without statistically significant difference between the mobilization technologies. All patients with more than 1.0 x 10 (6) CD34+ cells/kg in the first apheresis procedure reached the overall tar get of 2.5 x 10(6) CD34+ cells/kg after a second or subsequent mobilization procedure. In contrast, only 3 of 8 patients (37%) with less than 1.0 x 10 (6) CD34+ cells in the first harvest could reach the target of 2.5 x 10(6) CD34+ cells after further mobilization attempts. Copyright (C) 2000 S. Karg er AG, Basel.