title: Prospective cohort study of the circadian rhythm pattern in allogeneic sibling donors undergoing standard granulocyte colony-stimulating factor mobilization.
abstract: BACKGROUND
  Prior in vivo murine studies suggest circadian oscillations for hematopoietic stem cell release, which are maintained following administration of granulocyte colony-stimulating factor (G-CSF) or plerixafor. Furthermore, retrospective data analysis of healthy donors who underwent G-CSF-induced mobilization demonstrated significantly increased CD34(+) cell yields when collected in the afternoon compared with the morning.
  
  
  METHODS
  A prospective study was conducted to directly examine the number of peripheral blood CD34(+) and CD34(+)CD38- progenitor/stem cells at baseline and then every 6 hours for 24 hours on days 4 to 5 of G-CSF (10 μg/kg/day in the morning) mobilization in 11 allogeneic donors. Data were analyzed using mixed-model analysis of repeated measures.
  
  
  RESULTS
  Whereas we observed a significant increase in CD34(+) cell counts toward the evening, counts were then sustained on the morning of day 5. The correlation between CD34(+)CD38- cell counts and the less defined CD34(+) populations was weak.
  
  
  CONCLUSIONS
  Our results suggest that the pharmacodynamic activity and timing of G-CSF may alter endogenous progenitor rhythms. Donor age, medical history, and medications may also impact circadian rhythm. Further studies should examine the circadian rhythm at the peak of G-CSF mobilization and should consider potential confounders such as the time of G-CSF administration and the age of the subjects.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Shi
authors.forename: Luis M
authors.initials: LM
authors.lastname: Isola
authors.forename: Janice L
authors.initials: JL
authors.lastname: Gabrilove
authors.forename: Erin L
authors.initials: EL
authors.lastname: Moshier
authors.forename: James H
authors.initials: JH
authors.lastname: Godbold
authors.forename: Lorraine K
authors.initials: LK
authors.lastname: Miller
authors.forename: Paul S
authors.initials: PS
authors.lastname: Frenette
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism; D002940:Circadian Rhythm / Q000187:drug effects*; D015331:Cohort Studies; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D019337:Hematologic Neoplasms / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D035781:Siblings; D013997:Time Factors; D014019:Tissue Donors; D014184:Transplantation, Homologous; D055815:Young Adult
chemical_list: D018952:Antigens, CD34; D016179:Granulocyte Colony-Stimulating Factor