title: Progenitor cell recruitment during individualized high-flow, very-large-volume apheresis for autologous transplantation improves collection efficiency.
abstract: BACKGROUND
  Individual adaptation of processed patient's blood volume (PBV) should reduce number and/or duration of autologous peripheral blood progenitor cell (PBPC) collections.
  
  
  METHODS
  The durations of leukapheresis procedures were adapted by means of an interim analysis of harvested CD34+ cells to obtain the intended yield of CD34+ within as few and/or short as possible leukapheresis procedures. Absolute efficiency (AE; CD34+/kg body weight) and relative efficiency (RE; total CD34+ yield of single apheresis/total number of preapheresis CD34+) were calculated, assuming an intraapheresis recruitment if RE was greater than 1, and a yield prediction models for adults was generated.
  
  
  RESULTS
  A total of 196 adults required a total of 266 PBPC collections. The median AE was 7.99 x 10(6), and the median RE was 1.76. The prediction model for AE showed a satisfactory predictive value for preapheresis CD34+ only. The prediction model for RE also showed a low predictive value (R2 = 0.36). Twenty-eight children underwent 44 PBPC collections. The median AE was 12.13 x 10(6), and the median RE was 1.62. Major complications comprised bleeding episodes related to central venous catheters (n = 4) and severe thrombocytopenia of less than 10 x 10(9) per L (n = 16).
  
  
  CONCLUSIONS
  A CD34+ interim analysis is a suitable tool for individual adaptation of the duration of leukapheresis. During leukapheresis, a substantial recruitment of CD34+ was observed, resulting in a RE of greater than 1 in more than 75 percent of patients. The upper limit of processed PBV showing an intraapheresis CD34+ recruitment is higher than in a standard large-volume leukapheresis. Therefore, a reduction of individually needed PBPC collections by means of a further escalation of the processed PBV seems possible.
authors.affiliation: Department of Hematology and Central Hematology Laboratory, Inselspital, University Hospital, Bern, Switzerland. stefano.fontana@insel.ch
authors.forename: Stefano
authors.initials: S
authors.lastname: Fontana
authors.forename: Rachel
authors.initials: R
authors.lastname: Groebli
authors.forename: Kurt
authors.initials: K
authors.lastname: Leibundgut
authors.forename: Thomas
authors.initials: T
authors.lastname: Pabst
authors.forename: Caroline
authors.initials: C
authors.lastname: Zwicky
authors.forename: Behrouz Mansouri
authors.initials: BM
authors.lastname: Taleghani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018952:Antigens, CD34; D002408:Catheters, Indwelling / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D019650:Hematopoietic Stem Cell Mobilization / Q000009:adverse effects; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D007223:Infant; D007937:Leukapheresis; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D036102:Peripheral Blood Stem Cell Transplantation / Q000009:adverse effects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D013921:Thrombocytopenia / Q000209:etiology; D014182:Transplantation, Autologous
chemical_list: D018952:Antigens, CD34