title: Application of a clot-based assay to measure the procoagulant activity of stored allogeneic red blood cell concentrates.
abstract: Thrombotic effects are possible complications of red blood cell transfusion. The generation and accumulation of procoagulant red blood cell extracellular vesicles during storage may play an important role in these thrombotic effects. The objective of this study was to assess the value of a simple phospholipid-dependent clot-based assay (STA®-Procoag-PPL) to estimate the procoagulant activity of stored red blood cells and changes in this activity during storage of the blood component.
  
  
  
  Extracellular vesicles from 12 red blood cell concentrates were isolated at 13 storage time-points and characterised by quantitative and functional methods: the degree of haemolysis (direct spectrophotometry), the quantification and determination of cellular origin (flow cytometry) and the procoagulant activity (thrombin generation and STA®-Procoag-PPL assays) were assessed.
  
  
  
  The mean clotting time of extracellular vesicles isolated from red blood cell concentrates decreased from 117.2±3.6 sec on the day of collection to 33.8±1.3 sec at the end of the storage period. This illustrates the phospholipid-dependent procoagulant activity of these extracellular vesicles, as confirmed by thrombin generation. Results of the peak of thrombin and the STA®-Procoag-PPL were well correlated (partial r=-0.41. p<0.001). In parallel, an exponential increase of the number of red blood cell-derived extracellular vesicles from 1,779/μL to 218,451/μL was observed.
  
  
  
  The STA®-Procoag-PPL is a potentially useful technique for assessing the procoagulant activity of a red blood cell concentrate.
authors.affiliation: Department of Haematology, Université Catholique de Louvain, CHU UCL Namur, Namur Thrombosis and Hemostasis Center (NTHC), Yvoir, Belgium.
authors.forename: Bérangère
authors.initials: B
authors.lastname: Devalet
authors.affiliation: Department of Pharmacy, University of Namur, Namur Thrombosis and Haemostasis Centre (NTHC), Namur, Belgium.
authors.forename: Adeline
authors.initials: A
authors.lastname: Wannez
authors.affiliation: Haematology Laboratory, Université Catholique de Louvain, CHU UCL Namur, Namur Thrombosis and Hemostasis Center (NTHC), Yvoir, Belgium.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bailly
authors.affiliation: Department of Pharmacy, University of Namur, Namur Thrombosis and Haemostasis Centre (NTHC), Namur, Belgium.
authors.forename: Lutfiye
authors.initials: L
authors.lastname: Alpan
authors.affiliation: Haematology Laboratory, Université Catholique de Louvain, CHU UCL Namur, Namur Thrombosis and Hemostasis Center (NTHC), Yvoir, Belgium.
authors.forename: Damien
authors.initials: D
authors.lastname: Gheldof
authors.affiliation: Department of Pharmacy, University of Namur, Namur Thrombosis and Haemostasis Centre (NTHC), Namur, Belgium.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Douxfils
authors.affiliation: Blood Transfusion Centre-Mont-Godinne, Université Catholique de Louvain, CHU UCL Namur, Yvoir, Belgium.
authors.forename: Véronique
authors.initials: V
authors.lastname: Deneys
authors.affiliation: Scientific Support Unit, Université Catholique de Louvain, CHU UCL Namur, Yvoir, Belgium.
authors.forename: Benoît
authors.initials: B
authors.lastname: Bihin
authors.affiliation: Haematology Laboratory, Université Catholique de Louvain, CHU UCL Namur, Namur Thrombosis and Hemostasis Center (NTHC), Yvoir, Belgium.
authors.forename: Bernard
authors.initials: B
authors.lastname: Chatelain
authors.affiliation: Department of Pharmacy, University of Namur, Namur Thrombosis and Haemostasis Centre (NTHC), Namur, Belgium.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Dogné
authors.affiliation: Department of Pharmacy, University of Namur, Namur Thrombosis and Haemostasis Centre (NTHC), Namur, Belgium.
authors.forename: Christian
authors.initials: C
authors.lastname: Chatelain
authors.affiliation: Haematology Laboratory, Université Catholique de Louvain, CHU UCL Namur, Namur Thrombosis and Hemostasis Center (NTHC), Yvoir, Belgium.
authors.forename: François
authors.initials: F
authors.lastname: Mullier
mesh_terms: D000328:Adult; D001777:Blood Coagulation; D001780:Blood Coagulation Tests; D001793:Blood Preservation; D017707:Erythrocyte Transfusion / Q000009:adverse effects; D004912:Erythrocytes / Q000166:cytology* / Q000378:metabolism*; D000067128:Extracellular Vesicles / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013927:Thrombosis / Q000097:blood / Q000209:etiology; D013997:Time Factors; D065227:Transfusion Reaction / Q000097:blood