Blood stem cell procurement: donor safety issues.

Allogeneic transplantation of rhG-CSF-mobilized peripheral blood stem cells (PBSCs) is now being increasingly performed, but safety considerations for hematologically normal PBSC donors have not been fully addressed. Experience in this area is rapidly accumulating, however, and on the basis of currently available data, a consensus is gradually emerging on several issues: (1) rhG-CSF treatment and PBSC collection seem to have an acceptable short-term safety profile in normal donors. There is a need for continued safety monitoring, however. (2) rhG-CSF doses up to 10 microg/kg/day show a consistent dose-response relationship with the mobilization (and collection) of CD34+ progenitor cells, and this dose is acceptable for routine clinical use. Whether higher doses are superior (or cost-effective) remains to be determined, and they may produce more severe side-effects. The potential risks of marked leukocytosis (arbitrarily defined as a leukocyte count of more than 70 x 10(9)/l) have been a concern, and rhG-CSF dose reduction is performed by many centers to maintain leukocyte counts below this level. (3) Transient post-donation cytopenias, involving granulocytes, lymphocytes and platelets, may occur and are at least partly related to the leukapheresis procedure. These are generally asymptomatic and self-limited; follow-up blood counts are not necessarily required. Reinfusion of autologous platelet-rich plasma should be considered for donors with expected post-donation thrombocytopenia (platelet count