title: The effect of methylene blue phototreatment on plasma proteins and in vitro coagulation capability of single-donor fresh-frozen plasma.
abstract: BACKGROUND
  Photodynamic virus inactivation of fresh-frozen plasma (FFP) may result in its impaired coagulation capability.
  
  
  METHODS
  Double-volume plasmapheresis samples from 11 donors were divided in pairs of 250 mL. One group underwent methylene blue (MB) phototreatment (MB-FFP). The other group was treated according to the standards of the American Association of Blood Banks for preparation and storage of FFP. Parameters of hemostasis and clinically important plasma proteins were tested in native plasma, thawed MB-FFP, thawed FFP, and twice-frozen and thawed FFP (FFP-II).
  
  
  RESULTS
  Mean activities of factor V (73.4 vs. 94.5%; p < 0.01), factor VIII (58.1 vs. 86.7%; p < 0.001), and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) were reduced in MB-FFP as compared to those in FFP. The comparison of MB-FFP to FFP-II revealed reduced activities of factor VIII (58.1 vs. 85.2%; p < 0.001) and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) but no changes in factor V. Activated partial thromboplastin time in MB-FFP was prolonged beyond the upper normal range (+5.3 sec; p < 0.001) and prothrombin time increased in MB-FFP versus FFP (+0.96 sec; p < 0.001).
  
  
  CONCLUSIONS
  MB phototreatment reduces the in vitro coagulation capacity of FFP, most likely as a result of the effects of an additional freezing and thawing procedure and photooxidation-induced protein damage.
authors.affiliation: Department of Transfusion Medicine, University Hospital Rudolf Virchow, Free University of Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Zeiler
authors.forename: H
authors.initials: H
authors.lastname: Riess
authors.forename: G
authors.initials: G
authors.lastname: Wittmann
authors.forename: G
authors.initials: G
authors.lastname: Hintz
authors.forename: R
authors.initials: R
authors.lastname: Zimmermann
authors.forename: C
authors.initials: C
authors.lastname: Müller
authors.forename: H G
authors.initials: HG
authors.lastname: Heuft
authors.forename: D
authors.initials: D
authors.lastname: Huhn
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects* / Q000528:radiation effects; D001798:Blood Proteins / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D066298:In Vitro Techniques; D008027:Light; D008751:Methylene Blue / Q000494:pharmacology*; D010949:Plasma / Q000187:drug effects* / Q000382:microbiology / Q000528:radiation effects; D014780:Viruses / Q000187:drug effects / Q000528:radiation effects
chemical_list: D001798:Blood Proteins; D008751:Methylene Blue