Assessment of rapid remobilization intervals with G-CSF and SCF in murine and rhesus macaque models.
BACKGROUND
Defining the optimum regimen and time for repeat peripheral blood progenitor cell mobilization would have important clinical applications.


METHODS
Remobilization with SCF and G-CSF at 2 weeks after an initial mobilization in mice and at 2 or 4 weeks after an initial mobilization in nonhuman primates was examined. In mice, competitive repopulation assays were used to measure long-term progenitor cell-repopulating activity. In monkeys, mobilization of hematopoietic progenitor CFUs was used as a surrogate marker for progenitor cell-repopulating ability.


RESULTS
Efficacy of progenitor cell remobilization differed in the two animal species. In mice, peripheral blood progenitor cell-repopulating ability with repeat mobilization at 2 weeks was 70 percent of that with the initial mobilization. In monkeys, there was no significant difference in peripheral blood progenitor cell mobilization between the initial and the repeat mobilizations at 2 weeks. In mobilizations separated by 4 weeks, however, peripheral blood progenitor cell mobilization was higher than that with initial mobilizations.


CONCLUSIONS
In animal models, mobilization of peripheral blood progenitor cells with remobilization after a 2-week interval is similar to or moderately decreased from that with the initial mobilization. Progenitor cell collection at this time point may be useful in certain clinical circumstances. A 4-week interval between remobilizations may be preferable. Clinical trials in humans would be useful to clarify these issues.
Shi
P A
PA
Hematology Branch, National Heart, Lung, and Blood Institute, Bethesda, MD 20892-1652, USA. ps191o@nih.gov
Pomper
G J
GJ
Metzger
M E
ME
Donahue
R E
RE
Leitman
S F
SF
Dunbar
C E
CE
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D008253:Macaca mulatta / Q000097:blood*; D051379:Mice / Q000097:blood*; D008810:Mice, Inbred C57BL; D019089:Stem Cell Factor / Q000494:pharmacology*; D013997:Time Factors
D019089:Stem Cell Factor; D016179:Granulocyte Colony-Stimulating Factor