title: Evaluation of an experimental filter designed for improving the quality of red blood cells (RBCs) during storage by simultaneously removing white blood cells and immunomodulators and improving RBC viscoelasticity and Band 3 proteins.
abstract: BACKGROUND
  Storage age of red blood cells (RBCs) has been reported to be associated with increased mortality and morbidity. During storage, RBCs undergo changes in biochemical and functional properties. Stored RBCs may also contain white blood cells (WBCs), activated platelets (PLTs), cytokines, immunoglobulin, and other bioactive proteins. Transfusion of these bioactive proteins and cells with RBCs has the potential to cause serious adverse effects. We evaluated the performances of an experimental filter (EF) designed to remove immunoglobulins, cytokines, and other bioactive proteins in RBCs.
  
  
  METHODS
  Sixteen sets, each containing 3 units of ABO-identical RBCs in AS-3 were obtained from a blood bank. Three units of RBCs were combined together and then split into three equal aliquots, A, B, and C. Unit A was unfiltered while Units B and C were filtered with a leukoreduction filter and the EF, respectively. All the units were stored at 4°C in a blood bank refrigerator for 42 days. We measured RBC viscoelasticity, hemolysis, RBC adenosine triphosphate, Band 3 proteins, cytokines, PLTs, WBCs, and immunoglobulin before and after filtration and on Days 21 and 42 of storage. Data were analyzed by repeated-measures analysis of variance with Newman-Keuls multiple comparison test.
  
  
  RESULTS
  The EF significantly (p<0.05) reduced the levels of immunoglobulin (control IgG, 2.184 ± 1.918 mg/mL; BPF4, 2.216 ± 1.956 mg/mL; and EF, 0.363 ± 0.391 mg/mL), PLTs, cytokines, and improved viscoelastic properties when compared to either control or leukoreduced RBCs.
  
  
  CONCLUSIONS
  The EF achieved lower levels of WBCs, improved viscoelastic properties, and reduced levels of immunoglobulins and cytokines but significance will require clinical evaluation.
authors.affiliation: Haemonetics Corporation, Braintree, Massachusetts.
authors.forename: S O
authors.initials: SO
authors.lastname: Sowemimo-Coker
mesh_terms: D001792:Blood Platelets / Q000166:cytology; D001793:Blood Preservation / Q000379:methods*; D002469:Cell Separation / Q000379:methods; D004912:Erythrocytes / Q000166:cytology*; D005374:Filtration / Q000592:standards*; D006801:Humans; D047589:Leukocyte Reduction Procedures / Q000379:methods*; D007962:Leukocytes / Q000166:cytology