title: Back-priming of the RCM1 leucocyte-reduction filter: consequences for filtration efficacy.
abstract: OBJECTIVE
  The RCM1 leucocyte-reduction filter has been incorporated into two types of blood-donation sets of which one uses back-priming of the leucocyte filter with SAG-M solution. In this study we have compared the leucocyte-reduction efficacy of the RCM1 filter with or without back priming with SAG-M solution.
  
  
  METHODS
  This study was a retrospective analysis of quality control data of 3529 leucocyte-filtered red cell units. Of these, 1002 whole-blood units were collected in a donation set that was back-primed by letting the SAG-M solution in the final storage bag run backwards through the filter into the bag of concentrated red cells. The remaining 2527 units were collected in a donation set that required no back-priming. Postfiltration leucocyte concentration was assessed using flow cytometry.
  
  
  RESULTS
  There was a significant trend towards lower leucocyte concentration in the units in which back-priming of the filter preceded filtration, as compared to units filtered without back-priming [chi2trend= 18.8, degrees of freedom (d.f.) = 1, P < 0.0005].
  
  
  CONCLUSIONS
  Back-priming of the RCM1 filter for red cells with SAG-M solution is superior to no back-priming with regard to leucocyte-reduction efficacy.
authors.affiliation: Department of Immunology and Transfusion Medicine, Ullevaal University Hospital, Oslo, Norway. jens.kjeldsen-kragh@ioks.uio.no
authors.forename: J
authors.initials: J
authors.lastname: Kjeldsen-Kragh
authors.forename: E
authors.initials: E
authors.lastname: Golebiowska
mesh_terms: D001793:Blood Preservation / Q000379:methods; D017707:Erythrocyte Transfusion; D004912:Erythrocytes; D005374:Filtration; D005434:Flow Cytometry; D006801:Humans; D007962:Leukocytes; D010952:Plasma Substitutes; D011786:Quality Control; D012189:Retrospective Studies
chemical_list: D010952:Plasma Substitutes; C051020:SAG-M blood