title: The impact of whole blood processing and freezing conditions on the quality of therapeutic plasma prepared from whole blood.
abstract: BACKGROUND
  The quality of whole blood (WB)-derived plasma preparations has been the subject of several studies, but there has been a lack of robust, comparative data for the different methods of processing and freezing.
  
  
  METHODS
  Six WB-derived plasma units were pooled and split (n = 16) and frozen within either 8 or 24 hours after WB collection, stored at 4°C or at room temperature (RT), and then frozen either slowly at -20°C or rapidly to below -30°C. Plasma units were tested for fibrinogen, Factor (F)V, FVII, FVIII, FXI, and von Willebrand factor (VWF), protein C (PC), protein S (PS) activity and free PS, prothrombin time, and partial thromboplastin time.
  
  
  RESULTS
  FVIII was reduced by 9% to 19% after having been stored for 24 hours irrespective of storage temperature. Slow freezing (SF) reduced FVIII by 17% to 25% compared to rapid freezing (RF) to below -30°C. Storage temperature, but not 24-hour storage, decreased PS activity by 20% to 28%. PS activity was 8% to 17% lower in plasma units frozen slowly compared to RF. Storage and freezing had no influence on free PS. SF caused small losses of FVII and FXI activity.
  
  
  CONCLUSIONS
  Twenty-four-hour hold at RT and SF both reduce FVIII levels below 70 U/dL in many plasma units. PS activity is affected substantially by storage temperature and SF, but free PS is not. With regard to plasma quality, freezing to below -30°C within 1 hour is superior to SF at -20°C.
authors.affiliation: Transfusion Center, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Runkel
authors.affiliation: Transfusion Center, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
authors.forename: Walter E
authors.initials: WE
authors.lastname: Hitzler
authors.affiliation: Institute of Hemostaseology and Transfusion Medicine, Academic City Hospital, Ludwigshafen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Hellstern
mesh_terms: D000328:Adult; D001793:Blood Preservation / Q000379:methods*; D001798:Blood Proteins / Q000032:analysis; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010314:Partial Thromboplastin Time; D010949:Plasma; D011517:Prothrombin Time; D013696:Temperature; D013997:Time Factors
chemical_list: D001798:Blood Proteins