Re-mobilization of peripheral blood progenitor cells within a short time interval fails to achieve effective progenitor cell yields

We report the case of a healthy donor who was mobilized for the purpose of performing an unrelated donor transplantation with subcutaneous injections of rhG-CSF, Because of accidental loss of progenitors, 3 days after complet ing the first collection, the donor was mobilized again with rhG-CSF, and p rogenitors were collected. While a similar increase in the pre-apheresis le ukocyte count was observed in both procedures, fewer mononuclear cells were mobilized during the second rhG-CSF course, resulting in a poor CD34(+) yi eld, These data suggest that an 8-day interval between commencement of rhG- CSF mobilizations is insufficient to predict an efficient collection of hem atopoietic progenitors to ensure engraftment after bone marrow transplantat ion.