title: Preapheresis peripheral blood CD34+ mononuclear cell counts as predictors of progenitor cell yield.
abstract: BACKGROUND
  Peripheral blood progenitor cells, harvested by apheresis after mobilization, provide rapid hematologic recovery after high-dose chemotherapy. However, because harvesting these cells is expensive and time-consuming, there has been much interest in optimizing collection protocols. An investigation was made to determine whether, in this clinical setting, peripheral blood progenitor cell yields may be predicted from preapheresis progenitor cell counts, allowing the length of each procedure to be "fine tuned" to achieve specific target goals.
  
  
  METHODS
  Preapheresis peripheral blood CD34+ cell and total colony-forming cell counts were assessed before 78 peripheral blood progenitor cell collections from 13 consecutive patients were performed. Preapheresis counts were correlated with actual progenitor cell yields. Factors affecting this correlation were analyzed.
  
  
  RESULTS
  With the use of linear regression analysis preapheresis progenitor cell counts were found to correlate significantly but weakly with actual yields per kg of body weight per liter of blood processed (CD34+ cells: r = 0.43; colony-forming cells: r = 0.56). Further analysis revealed two possible causes: 1) circulating progenitor cell concentrations fluctuate widely during harvest, which implies that preapheresis counts are not representative of actual concentrations during apheresis, and 2) the efficiency with which apheresis machines extract mononuclear cells varies greatly between procedures.
  
  
  CONCLUSIONS
  Preapheresis CD34+ and colony-forming cell counts correlated poorly with subsequent yields in this clinical setting, which suggests that it is not practical to use such counts to predict with certainty the length of apheresis needed to achieve a target yield.
authors.affiliation: Brigham and Women's Hospital, Dana Farber Cancer Institute, Boston, MA, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Benjamin
authors.forename: L
authors.initials: L
authors.lastname: Linsley
authors.forename: D
authors.initials: D
authors.lastname: Fountain
authors.forename: W H
authors.initials: WH
authors.lastname: Churchill
authors.forename: C
authors.initials: C
authors.lastname: Sieff
authors.forename: M E
authors.initials: ME
authors.lastname: Cannon
authors.forename: L
authors.initials: L
authors.lastname: Uhl
authors.forename: L
authors.initials: L
authors.lastname: Gaynes
authors.forename: J H
authors.initials: JH
authors.lastname: Antin
authors.forename: C
authors.initials: C
authors.lastname: Wheeler
mesh_terms: D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000032:analysis*; D001772:Blood Cell Count / Q000187:drug effects; D001781:Blood Component Removal; D001800:Blood Specimen Collection; D003114:Colony-Forming Units Assay; D003520:Cyclophosphamide / Q000494:pharmacology; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000637:transplantation; D008875:Middle Aged
chemical_list: D018952:Antigens, CD34; D016179:Granulocyte Colony-Stimulating Factor; D003520:Cyclophosphamide