title: CD34+ cells obtained from "good mobilizers" are more activated and exhibit lower ex vivo expansion efficiency than their counterparts from "poor mobilizers".
abstract: BACKGROUND
  The classification of patients into "good" or "poor" mobilizers is based on CD34+ cell count in their peripheral blood (PB) after granulocyte-colony-stimulating factor (G-CSF) injection. We hypothesized that, apart from their mobilization from marrow to the blood, the response to G-CSF of CD34+ cells also includes activation of proliferation, metabolic activity, and proliferative capacity.
  
  
  METHODS
  Mobilized PB CD34+ cells purified from samples obtained by cytapheresis of multiple myeloma or non-Hodgkin's lymphoma patients of both good (>50 CD34+ cells/microL) and poor (< or =50 CD34+ cells/microL) mobilizers were studied. The initial cell cycle state of CD34+ cells after selection and their kinetics of activation (exit from G(0) phase) during ex vivo culture were analyzed. Their proliferative capacity was estimated on the basis of ex vivo generation of total cells, CD34+ cells, and colony-forming cells (CFCs), in a standardized expansion culture. Indirect insight in metabolic activity was obtained on the basis of their survival (viability and apoptosis follow-up) during the 7-day-long conservation in hypothermia (4 degrees C) in the air or in atmosphere containing 3% O(2)/6% CO(2).
  
  
  RESULTS
  CD34+ cells obtained from good mobilizers were in lower proportion in the G(0) phase, their activation in a cytokine-stimulated culture was accelerated, and they exhibited a lower ex vivo expansion efficiency than those from poor mobilizers. The resistance to hypothermia of good immobilizers' CD34+ cells is impaired.
  
  
  CONCLUSIONS
  A good response to G-CSF mobilization treatment is associated with a higher degree of proliferative and metabolic activation of mobilized CD34+ cells with a decrease in their expansion capacity.
authors.affiliation: Aquitaine-Limousin Branch of French Blood Institute and the University Victor Segalen Bordeaux 2, Bordeaux, France. zoran.ivanovic@efs.sante.fr
authors.forename: Zoran
authors.initials: Z
authors.lastname: Ivanovic
authors.forename: Milica
authors.initials: M
authors.lastname: Kovacevic-Filipovic
authors.forename: Michel
authors.initials: M
authors.lastname: Jeanne
authors.forename: Leslie
authors.initials: L
authors.lastname: Ardilouze
authors.forename: Anne
authors.initials: A
authors.lastname: Bertot
authors.forename: Milène
authors.initials: M
authors.lastname: Szyporta
authors.forename: Francis
authors.initials: F
authors.lastname: Hermitte
authors.forename: Xavier
authors.initials: X
authors.lastname: Lafarge
authors.forename: Pascale
authors.initials: P
authors.lastname: Duchez
authors.forename: Marija
authors.initials: M
authors.lastname: Vlaski
authors.forename: Noel
authors.initials: N
authors.lastname: Milpied
authors.forename: Mirjana
authors.initials: M
authors.lastname: Pavlovic
authors.forename: Vincent
authors.initials: V
authors.lastname: Praloran
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Boiron
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism; D017209:Apoptosis / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D015925:Cryopreservation; D004734:Energy Metabolism / Q000502:physiology*; D016193:G1 Phase / Q000502:physiology; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage*; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D010100:Oxygen / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000502:physiology
chemical_list: D018952:Antigens, CD34; D002245:Carbon Dioxide; D016179:Granulocyte Colony-Stimulating Factor; D010100:Oxygen