Comparison of CD34+ cell mobilization, blood graft cellular composition, and post-transplant outcome in myeloma patients mobilized with filgrastim or pegfilgrastim added to low-dose cyclophosphamide: A prospective multicenter study.

Abstract

Scarce data exist on the impact of granulocyte-colony stimulating factor (G-CSF) type on the mobilizing capacity of CD34+ cells, graft cellular composition, and outcome in myeloma (MM) patients. In this prospective multicenter study, 70 patients with MM received filgrastim (FIL) and 20 patients received pegfilgrastim (PEG) as a G-CSF after low-dose cyclophosphamide. Flow cytometry was used to analyze the mobilization of CD34+ cells and cellular composition of blood grafts, hematologic recovery, and survival after auto-SCT according to the G-CSF choice. The CD34+ cell yield of the first apheresis was higher in the FIL group (5.3 vs. 4.2 × 106 /kg, p=.025). The better mobilizing capacity was observed in the FIL group especially after bortezomib-based induction based on the higher first apheresis yield of CD34+ cells (7.5 vs. 4.4 × 106 /kg, p=.001). The median CD19+ cell count (1.0 vs. 0.4 × 106 /kg, p=.010) and the number of CD3+ T lymphocytes (43.1 vs. 31.8 × 106 /kg, p=.122) in the infused graft were higher in the patients mobilized with FIL. Both early (day +15) (56 vs. 108 × 109 /L, p=.002) and later platelet recovery at 6 months (191 vs. 226 × 109 /L, p=.026) were faster in the PEG group. G-CSF type seems to impact on the mobilization capacity and cellular composition of infused graft and also platelet recovery post-transplant. A randomized study might be warranted to verify the effects of G-CSF choice in the mobilization field.