Factors affecting the efficiency of peripheral blood stem cell collection in children treated with chemotherapy and G‐CSF

Abstract

This retrospective study attempts to clarify the optimal timing for peripheral blood stem cell (PBSC) collection after conventional chemotherapy followed by granulocytecolony stimulating factor (G-CSF) administration. Leukapheresis was performed 32 times in nine children with various cancers during bone marrow recovery phase following transient pancytopenia after chemotherapy. (On two occasions, leukapheresis was excluded because many leukemic blasts were included.) When the number of white blood cells (WBC) exceeded 1.8 x 10lo/L after administration of G-CSF (200 pg/m2, continuous infusion), many more CD34 + cells were contained in the collected peripheral mononuclear cells (P > 0.02) and a sufficient number of PBSC for transplantation (t 10 x 108 CD34 + cellskg) was obtained after one run in 15 of 17 leukapheresis sessions. In contrast, sufficient PBSC were obtained only in one of 13 r~n S of leukapheresis when the number of WBC was < 1.8 x 10IO/L. The number of WBC on the day when PBSC were collected correlated with collected nuclear cell number (r = 0.60), but not with the CD34 + cell ratio. The ratio was higher only when both platelets and reticulocytes increased in parallel with WBc. We conclude that sufficient PBSC collection is possible after conventional chemotherapy using G-CSF, when hematopoietic recovery is parallel, without the use of high-dose chemotherapy.

Hourly monitoring of circulating CD34+ cells to optimize timing of autologous apheresis in pediatric patients

“…The numbers of collected progenitor cells correlate well with the concentration of CD34 þ progenitor cells in PB on the day of apheresis, whereas white blood cell (WBC) counts are only weakly predictive. [5][6][7][8][9][10][11] To optimize yields, different modes of stem cell mobilization from the bone marrow have been tested. These include dose variation of G-CSF, cytotoxic, [12][13][14] steady-state 15,16 and combined mobilization, 17,10 mode of administration (subcutaneous vs intravenous), type of growth factor (G-CSF vs GM-CSF 18,19 ), the influence of large volume apheresis (LVA 20,21 ), as well as timing of administration in terms of days or hours before apheresis.…”