title: Buffy coat (top/bottom)- and whole-blood filtration (top/top)-produced red cell concentrates differ in size of extracellular vesicles.
abstract: OBJECTIVE
  The influence that blood component separation methods have on changes to the red blood cell membrane during storage is not well understood. In Canada, red cell concentrates (RCCs) are produced using the buffy coat (BC, top/bottom) and the whole-blood filtration (WBF, top/top) methods, and this study aimed at comparing their influence on the characteristics of the extracellular vesicles (EV) which accumulated in the respective products during storage.
  
  
  METHODS
  Using flow cytometry, dynamic light scattering and mass spectrometry, we assessed RCC EVs for concentration, size, lipid composition and correlation with supernatant haemoglobin (Hb).
  
  
  RESULTS
  Accumulation of RBC EVs (CD235a(+) ) with storage time was similar in WBF and BC RCCs. The size of the EVs changed from <100 nm at d5 to near 200 nm by d42, with the EVs from WBF being smaller (P < 0·001) than BC RCCs at all storage times. The amount of EV-bound Hb in the WBF and BC units was similar (about 10% of total supernatant Hb). WBF EVs and BC EVs displayed similar lipid composition.
  
  
  CONCLUSIONS
  Haemolysis and EVs increase in BC and WBF RCCs during storage. Differences in the size characteristics of the EVs in WBF and BC RCCs suggest that non-RBC EVs are more prevalent in WBF products. Understanding the impact that manufacturing has on the characteristics of the different populations of EVs in RCCs will aid quality improvement efforts.
authors.affiliation: Centre for Innovation, Canadian Blood Services, Edmonton, AB, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Bicalho
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada.
authors.forename: A S
authors.initials: AS
authors.lastname: Pereira
authors.affiliation: Centre for Innovation, Canadian Blood Services, Edmonton, AB, Canada.|Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada.
authors.forename: J P
authors.initials: JP
authors.lastname: Acker
mesh_terms: D058621:Blood Buffy Coat / Q000166:cytology; D001781:Blood Component Removal / Q000379:methods*; D001793:Blood Preservation; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D000067493:Dynamic Light Scattering; D004912:Erythrocytes / Q000166:cytology* / Q000378:metabolism; D000067128:Extracellular Vesicles / Q000737:chemistry / Q000502:physiology*; D005374:Filtration; D005434:Flow Cytometry; D006454:Hemoglobins / Q000032:analysis / Q000378:metabolism; D006461:Hemolysis; D006801:Humans; D010316:Particle Size; D010743:Phospholipids / Q000032:analysis; D053719:Tandem Mass Spectrometry
chemical_list: D006454:Hemoglobins; D010743:Phospholipids
keywords: blood manufacturing; component separation; extracellular vesicles; microparticles; microvesicles; phosphatidylserine