title: Prediction of CD34(+) cell yield in hematopoietic cell products from children by peripheral blood CD34(+) cell counts.
abstract: OBJECTIVE
  Peripheral blood stem cells (PBSC) are increasingly used as an alternative to bone marrow in autologous transplantations. In adult patients, the peripheral blood CD34(+) cell count is a good predictor of CD34(+) cell yield in apheresis. However, the determinants of stem cell yield in the pediatric population have not been well established.
  
  
  METHODS
  We retrospectively studied 396 apheresis procedures in 301 pediatric patients. Receiver operating characteristic (ROC) curves based on pre-apheresis peripheral blood CD34(+) cell counts were generated to facilitate prediction of the optimal timing of PBSC collection. The associations between CD34(+) cell yield and age and mobilization regimen were analyzed.
  
  
  RESULTS
  Significant differences in CD34(+) cell yield among different age groups were observed. Furthermore, higher CD34(+) cell yields were obtained in patients receiving chemotherapy as part of the mobilization regimen than those without chemotherapy. A correlation was noted between the CD34(+) cell yield and blood surrogate markers, including white blood cell count, absolute neutrophil count and pre-apheresis peripheral blood CD34(+) cell count. Cut-off values of > 35 CD34(+) cells/μL in patients < 15 years old and > 45 CD34(+) cells/μL in patients ≥ 15 years old were strong predictors of an adequate PBSC collection in one apheresis session. For clinical use, ROC curves and tables were generated to assist advance planning for PBSC collection.
  
  
  CONCLUSIONS
  The pre-apheresis peripheral blood CD34(+) cell count is most useful in predicting PBSC yield. Our new cut-off values have better operating characteristics for children than the conventional value of 20 CD34(+) cells/μL used for adults.
authors.affiliation: Department of Bone Marrow Transplantation and Cellular Therapy, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
authors.forename: Piya
authors.initials: P
authors.lastname: Rujkijyanont
authors.forename: John
authors.initials: J
authors.lastname: Hipps
authors.forename: Kwan
authors.initials: K
authors.lastname: Gan
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.forename: Terrence L
authors.initials: TL
authors.lastname: Geiger
authors.forename: Paul W
authors.initials: PW
authors.lastname: Eldridge
authors.forename: Wing
authors.initials: W
authors.lastname: Leung
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism*; D001781:Blood Component Removal; D002648:Child; D002675:Child, Preschool; D005260:Female; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007937:Leukapheresis; D008297:Male; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D018952:Antigens, CD34