title: Thrombin generation and coagulation factor content of thawed plasma and platelet concentrates.
abstract: BACKGROUND
  We assessed the haemostatic capacity of thawed plasma produced after ambient storage of whole blood for 24 h (RTFP24), and the supernatant of buffy-coat derived platelet concentrates (PC).
  
  
  METHODS
  Platelet concentrates (n = 20) were tested on days 1, 5 and 7 of storage at 22°C and RTFP24 (n = 10) immediately following thawing and after 4 and 6 days storage at 4°C. Coagulation factor activity, thrombin generation ± an activator of protein C (PROTAC) and rotational thromboelastometry (ROTEM) were assessed.
  
  
  RESULTS
  In plasma and buffy-coat derived PC, there was a < 10% loss of factors II, IX and FX, but much higher loss of factors FV, FVII and FVIII. In plasma, the total or peak amount of thrombin generated was unaffected by storage for 6 days, with or without Protac, but there was an increase in lag time and decreased rate of clot formation by ROTEM. In PC, but not plasma, there was a 16% increase in FXII activity and increase in resistance to activated protein C, co-incidental to 30% loss of free protein S.
  
  
  CONCLUSIONS
  These data suggest thrombin generation is relatively unaltered when RTFP24 is thawed and stored for 6 days, and that the supernatant of PC has significant haemostatic capacity.
authors.affiliation: Component Development Laboratory, NHS Blood & Transplant, Brentwood, UK.
authors.forename: P
authors.initials: P
authors.lastname: Cookson
authors.forename: A
authors.initials: A
authors.lastname: Lawrie
authors.forename: L
authors.initials: L
authors.lastname: Green
authors.forename: E
authors.initials: E
authors.lastname: Dent
authors.forename: S
authors.initials: S
authors.lastname: Proffitt
authors.forename: S
authors.initials: S
authors.lastname: Bashir
authors.forename: S
authors.initials: S
authors.lastname: Thomas
authors.forename: R
authors.initials: R
authors.lastname: Cardigan
mesh_terms: D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000378:metabolism*; D001792:Blood Platelets / Q000378:metabolism*; D005615:Freezing; D006801:Humans; D010949:Plasma / Q000378:metabolism*; D013917:Thrombin / Q000378:metabolism*
chemical_list: D001779:Blood Coagulation Factors; D013917:Thrombin
keywords: blood components; blood processing; platelet concentrates plasma