Higher Efficacy of Peripheral Blood Stem Cell Collection in Children Mobilized with High-Dose G-CSF.

Objective: Analysis of efficacy of PBSC collection after mobilization by high-dose G-CSF in children and young adults, qualified for transplantation of autologous hematopoietic stem cells.

Patients and Methods: Total number of 21 patients (23 collection cycles) were included into the study, divided into 2 groups: group I of 10 patients (aged 16m-23y, weight 8.5–61kg) with solid tumors were mobilized with G-CSF (Neupogen) at dose 2x5 μg/kg bw/day (12 collection cycles); group II of 11 patients (aged 3–27y, weight 12.5–68kg) with solid tumors (n=6) or hematological malignancies (n=5), who were mobilized with G-CSF (Neupogen) at dose 2x12 μg/kg bw/day. PBSC collections were performed by COBE Spectra from the day when CD34 cell count exceeded 20/μl. Efficacy of procedure was determined by collection of total 2x10⁶ CD34 cells/kg (minimal required cell dose), or 5x10⁶ CD34 cells/kg (optimal cell dose).

Results: Group I: Peripheral blood CD34 cell count exceeded 20/μl in 7/12 (58%) patients at day 4 and 10/12 (83%) at day 6 of G-CSF administration. Total number of CD34 cells of 2x10⁶ /kg kw and 5x10⁶ /kg bw was obtained in 3/12 (25%) and 2/12 (17%) patients after first collection respectively; and in 8/12 (67%) and 4/12 (33%) after second collection, respectively. After 3 days of collection required number of cells was obtained in 9/12 (75%) and 6/12 (50%) patients, respectively. No patient reported side-effects related to G-CSF administration. Group II: Peripheral blood CD34 cell count exceeded 20/μl in 8/11 (73%) patients at day 4 and 11/11 at day 6 of G-CSF administration. Total number of CD34 cells of 2x10⁶ /kg bw and 5x10⁶ /kg bw was obtained in 9/11 (82%) and 3/11 (27%) patients after first collection respectively; and in 11/11 and 6/11 (55%) after second collection, respectively. After 3 days of collection, in all patients, but one, optimal number of cells was obtained. Two patients reported side-effects related to G-CSF administration (headache, bone pain). No differences were found between the rate of speed of PBSC mobilization in analyzed schemes of G-CSF administration, however group of patients mobilized with high-dose G-CSF, showed more efficient stem cell collection after 3 days of procedure (p=0.027; OR=14; 95%CI=1.1–402).

Conclusion: Mobilization of PBSC with high-dose G-CSF is a safe and effective method of hematopoietic stem cell collection, enabling high efficacy of this procedure.