title: Inverse relationship between patient peripheral blood CD34+ cell counts and collection efficiency for CD34+ cells in two automated leukapheresis systems.
abstract: BACKGROUND
  The purpose of this study was to analyze the CD34 cell collection efficiency (CE) of automated leukapheresis protocols of two blood cell separators (Spectra, COBE [AutoPBSC protocol] and AS104, Fresenius [PBSC-Lym, protocol]) for peripheral blood progenitor cell (PBPC) harvest in patients with malignant diseases.
  
  
  METHODS
  PBPCs were collected by the Spectra AutoPBSC protocol in 95 patients (123 collections) and the AS104 PBSC-Lym protocol in 87 patients (115 harvests). Patients underwent a median of one (range, 1-4) conventional-volume apheresis procedure of 10.8 L (9.0-13.9) to obtain a target cell dose of > or =2.5 x 10(6) CD34+ cells per kg.
  
  
  RESULTS
  The median overall CD34 CE was significantly better on the AS104 than on the Spectra: 55.8 percent versus 42.4 percent (p = 0.000). This was also true below (59.2% vs. 50.1%; p = 0.022) and above (51.2% vs. 41.3%; p = 0.001) the preleukapheresis threshold of 40 CD34+ cells per microL needed to collect a single-apheresis autograft. However, at > or =40 circulating CD34+ cells per microL, both cell separators achieved the target of > or =2.5 x 10(6) CD34+ cells per kg. The CD34 CE dropped significantly, from 59.2 percent at <40 cells per microL to 51.2 percent at > or =40 cells per microL on the AS104 (p = 0.017) and from 50.1 percent to 41.3 percent on the Spectra (p = 0.033).
  
  
  CONCLUSIONS
  Whereas the CD34 CE was significantly different with the AS104 and the Spectra, the CD34 CE of both machines correlated inversely with peripheral blood CD34+ cell counts, showing a significant decline with increasing numbers of circulating CD34+ cells. Nevertheless, at > or 40 preapheresis CD34+ cells per microL, sufficient hematopoietic autografts of > or =2.5 x 10(6) CD34+ cells per kg were harvested by a single conventional-volume (11 L) leukapheresis on both cell separators.
authors.affiliation: Blood Bank and Division of Hematology/Oncology, Department of Internal Medicine, Charité University Hospital/Virchow Clinic, Humboldt University, Berlin, Germany. heuft.hans-gert@mh-hannover.de
authors.forename: H G
authors.initials: HG
authors.lastname: Heuft
authors.forename: M
authors.initials: M
authors.lastname: Dubiel
authors.forename: O
authors.initials: O
authors.lastname: Rick
authors.forename: D
authors.initials: D
authors.lastname: Kingreen
authors.forename: S
authors.initials: S
authors.lastname: Serke
authors.forename: N
authors.initials: N
authors.lastname: Schwella
mesh_terms: D000293:Adolescent; D000328:Adult; D018952:Antigens, CD34 / Q000097:blood*; D001772:Blood Cell Count; D001800:Blood Specimen Collection / Q000592:standards; D005260:Female; D006801:Humans; D007937:Leukapheresis / Q000295:instrumentation* / Q000592:standards; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric
chemical_list: D018952:Antigens, CD34