The Mobilization Effects of G-CSF, GM-CSF and Darbepoetin-α for Allogeneic Peripheral Blood Stem Cell Transplantation.

Background: Granulocyte colony-stimulating-factor (G-CSF) is widely used for the mobilization of hematopoietic stem cells from normal donors. It has been reported that the addition of granulocyte-macrophage CSF (GM-CSF) to G-CSF mobilized more primitive CD34+ subsets than did G-CSF alone. We investigated the effects of combination regimen (GM-CSF + G-CSF + darbepoetin-α) for mobilization in normal healthy donors and compared its efficacy in mobilizing stem cells with G-CSF alone.

Methods: Thirty donors were randomly assigned to one of the following regimens for mobilization: G-CSF group (G-CSF 5ug/kg/day for 5 to 7 days) and combination group (GM-CSF 10ug/kg/day on 1^st and 2^nd days, G-CSF 5ug/kg/day for 5 to 7 days and 40mg of dalbepoetin-α on day 1)

Results: The counts of MNC and CD34+ cells/kg were not significantly different between two groups (p=0.129 and p=0.651). The CD3+ cell counts per kilogram were 3.48±1.45×10⁸/kg and 2.54±0.94×10⁸/kg in a G-CSF group and a combination group, respectively (p=0.04). Red blood cell transfusion requirement was not different between two groups (p=0.469). The median time to neutrophil and platelet engraftment was 12.5 vs. 12.0 days (p=0.443) and 11.5 vs. 11.0 days (p=0.752). Red blood cell recovery was 7.5 days and 7 days in G-CSF group and combination group, respectively (p=0.231). Grade II–IV acute graft-versus-host disease (GVHD) was observed in 20% in G-CSF group and 13% in combination group (p=0.50).

Conclusion: The combination regimen was not superior to G-CSF alone in terms of acute GVHD and CD34+ cell dose. But CD3+ cell count was significantly lower in combination regimen group. The role of lower CD3+ cells in the graft need to be elucidated in the future.