title: Prestorage WBC filtration of RBC units with soft-shell filters: filtration performance and impact on RBCs during storage for 42 days.
abstract: BACKGROUND
  The introduction of universal WBC filtration of RBCs prior to storage is currently under consideration in many countries, as it is thought to minimize the incidence of transfusion-associated adverse effects. Centrifugation of blood containers with newly developed soft-shell WBC filters is more convenient, and so of great interest.
  
  
  METHODS
  Two different quadruple blood pack systems with integrated soft-shell WBC filters were compared (Sepacell OptiPure RC, Baxter Biotech, vs. LCR 5, Maco Pharma). Buffy coat-depleted RBC units were investigated from whole-blood donations that were held for 2 to 3 hours before centrifugation and subsequent filtration at 22 degrees C (Group 1, OptiPure RC, 450 mL; Group 2, LCR 5, 450 mL; Group 3, OptiPure RC, 500 mL; Group 4, LCR 5, 500, mL, n = 12 per group). Filtration performance was analyzed, and the impact of WBC filtration on hemolysis rate, Hb content, pH, supernatant potassium, ATP, and 2,3 DPG was investigated weekly during storage for 42 days.
  
  
  RESULTS
  Filtration reduced the WBC count by 4.4 to 5.1 log. Mean +/- SD Hb content was 44.7 +/- 3.0, 41.2 +/- 3.3, 53.1 +/- 5.0, and 51.5 +/- 6.3 g per unit, respectively, with a corresponding mean RBC recovery after filtration of 71.0 +/- 3.0, 68.3 +/- 3.3, 76.6 +/- 1.7, and 68.9 +/- 4.5 percent. WBC filtration resulted in a significant reduction of Hct (0.10-0.14) in all four groups. Investigation of all RBC storage variables revealed acceptable values throughout the storage for 42 days.
  
  
  CONCLUSIONS
  WBC filtration with two newly developed soft-shell filters showed acceptable WBC-reduction efficacy without any difference between filter types in buffy coat-depleted RBCs from 450- and 500-mL whole-blood donations. However, the application of both filters resulted in an unacceptably low RBC recovery after filtration, which was particularly evident with the LCR5 filter. Our findings raise concern that WBC reduction with these filters may result in the production of RBCs with an inappropriately low Hb concentration.
authors.affiliation: Institute of Immunology and Transfusion Medicine, University of Lübeck School of Medicine, Lübeck, Germany. muellerst@immu.mu-luebeck.de
authors.forename: Michael
authors.initials: M
authors.lastname: Müller-Steinhardt
authors.forename: Holger
authors.initials: H
authors.lastname: Hennig
authors.forename: Holger
authors.initials: H
authors.lastname: Kirchner
authors.forename: Peter
authors.initials: P
authors.lastname: Schlenke
mesh_terms: D019794:2,3-Diphosphoglycerate / Q000097:blood; D000255:Adenosine Triphosphate / Q000097:blood; D001781:Blood Component Removal / Q000379:methods*; D001793:Blood Preservation; D017707:Erythrocyte Transfusion; D004912:Erythrocytes; D005374:Filtration / Q000295:instrumentation*; D006454:Hemoglobins / Q000032:analysis; D006461:Hemolysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007958:Leukocyte Count; D007962:Leukocytes; D011188:Potassium / Q000097:blood; D012044:Regression Analysis; D013997:Time Factors
chemical_list: D006454:Hemoglobins; D019794:2,3-Diphosphoglycerate; D000255:Adenosine Triphosphate; D011188:Potassium