title: The predictive value of white cell or CD34+ cell count in the peripheral blood for timing apheresis and maximizing yield.
abstract: BACKGROUND
  The collection of peripheral blood stem and progenitor cells (PBPCs) for transplantation can be time-consuming and expensive. Thus, the utility of counting CD34+ cells and white cells (WBCs) in the peripheral blood was evaluated as a predictor of CD34+ cell yield in the apheresis component.
  
  
  METHODS
  The WBC and CD34+ cell counts in the peripheral blood and the apheresis components from 216 collections were assessed. Sixty-three patients underwent mobilization with chemotherapy plus filgrastim, and 17 patients and 14 allogeneic PBPC donors did so with filgrastim alone. The relationship between the number of WBC and CD34+ cells in the peripheral blood and in the apheresis component was analyzed by using rank correlation and linear regression analysis.
  
  
  RESULTS
  The correlation coefficient for CD34+ cells per liter of peripheral blood with CD34+ cell yield (x 10(6)/kg) was 0.87 (n = 216 collections). This correlation existed for many patient and collection variables. However, patients with acute myeloid leukemia had fewer CD34+ cells in the apheresis component at any level of peripheral blood CD34+ cell count. Components collected from patients with CD34+ cell counts below 10 x 10(6) per L in the peripheral blood contained a median of 0.75 x 10(6) CD34+ cells per kg. When the WBC count in the blood was below 5.0 x 10(9) per L, the median number of CD34+ cells in the peripheral blood was 5.6 x 10(6) per L (range, 1.0-15.5 x 10(6)/L). A very poor correlation was found between the WBC count in the blood and the CD34+ cell yield (p = 0.12, n = 158 collections).
  
  
  CONCLUSIONS
  The number of CD34+ cells, but not WBCs, in the peripheral blood can be used as a predictor for timing of apheresis and estimating PBPC yield. This is a robust relationship not affected by a variety of patient and collection factors except the diagnosis of acute myeloid leukemia. Patients who undergo mobilization with chemotherapy and filgrastim also should undergo monitoring of peripheral blood CD34+ cell counts, beginning when the WBC count in the blood exceeds 1.0 to 5.0 x 10(9) per L.
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, University of Washington, Seattle 98109-1024, USA.
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.forename: W
authors.initials: W
authors.lastname: Leisenring
authors.forename: W I
authors.initials: WI
authors.lastname: Bensinger
authors.forename: L A
authors.initials: LA
authors.lastname: Holmberg
authors.forename: S D
authors.initials: SD
authors.lastname: Rowley
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D018952:Antigens, CD34 / Q000097:blood*; D001781:Blood Component Removal; D001800:Blood Specimen Collection; D001835:Body Weight / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology*; D006801:Humans; D007958:Leukocyte Count; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D018952:Antigens, CD34