title: Microparticles in stored red blood cells: an approach using flow cytometry and proteomic tools.
abstract: OBJECTIVE
  Microparticles (MPs) are small phospholipid vesicles of less than 1 microm, shed in blood flow by various cell types. These MPs are involved in several biological processes and diseases. MPs have also been detected in blood products; however, their role in transfused patients is unknown. The purpose of this study was to characterize those MPs in blood bank conditions.
  
  
  METHODS
  Qualitative and quantitative experiments using flow cytometry or proteomic techniques were performed on MPs derived from erythrocytes concentrates. In order to count MPs, they were either isolated by various centrifugation procedures or counted directly in erythrocyte concentrates.
  
  
  RESULTS
  A 20-fold increase after 50 days of storage at 4 degrees C was observed (from 3370 +/- 1180 MPs/microl at day 5 to 64 850 +/- 37 800 MPs/microl at day 50). Proteomic analysis revealed changes of protein expression comparing MPs to erythrocyte membranes. Finally, the expression of Rh blood group antigens was shown on MPs generated during erythrocyte storage.
  
  
  CONCLUSIONS
  Our work provides evidence that storage of red blood cell is associated with the generation of MPs characterized by particular proteomic profiles. These results contribute to fundamental knowledge of transfused blood products.
authors.affiliation: Service Régional Vaudois de Transfusion Sanguine, Lausanne, Switzerland.
authors.forename: O
authors.initials: O
authors.lastname: Rubin
authors.forename: D
authors.initials: D
authors.lastname: Crettaz
authors.forename: G
authors.initials: G
authors.lastname: Canellini
authors.forename: J-D
authors.initials: JD
authors.lastname: Tissot
authors.forename: N
authors.initials: N
authors.lastname: Lion
mesh_terms: D000094902:Blood Banking / Q000379:methods; D001793:Blood Preservation / Q000009:adverse effects; D055252:Cell-Derived Microparticles; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D004912:Erythrocytes / Q000166:cytology*; D005434:Flow Cytometry; D006801:Humans; D040901:Proteomics