title: Coagulation factor levels in cryosupernatant prepared from plasma treated with amotosalen hydrochloride (S-59) and ultraviolet A light.
abstract: BACKGROUND
  The standard treatment for thrombotic thrombocytopenic purpura (TTP) is plasma exchange with fresh-frozen plasma (FFP). Exposure to large volumes of FFP increases the risk of transfusion-transmitted infections. Cryosupernatant (CSP) offers a theoretical advantage over FFP, because it lacks the large von Willebrand factor (VWF) forms implicated in the pathogenesis of TTP. This study compared the hemostatic variables of CSP prepared from FFP treated with a photochemical pathogen inactivation process to CSP prepared from conventional FFP.
  
  
  METHODS
  Forty CSP units were prepared from North American blood group A donor FFP. Twenty-one of the FFP units were individually treated with amotosalen hydrochloride (S-59) and ultraviolet A light (test, photochemically treated FFP), and 19 units were not treated (control, FFP).
  
  
  RESULTS
  Hemostatic variables of test and control CSP were similar and within reported ranges for conventional FFP with the exception of those properties depleted in CSP. VWF-cleaving protease activity (VWF:CP) and protein S (PS) levels (total and free antigen and activity) were within the conventional FFP reference range for test and control CSP. There were statistical differences between test and control CSP for alpha(2)-antiplasmin, antithrombin, protein C, and VWF:CP on a per-volume basis, but all levels were within the reference range for FFP, and the differences were not significant when expressed per gram of CSP protein.
  
  
  CONCLUSIONS
  S-59-treated CSP retained adequate levels of critical plasma proteins for plasma exchange therapy in acute TTP. The data indicate good preservation of hemostasis control proteins such as PS, alpha(2)-antiplasmin, and VWF:CP activity (ADAMTS13).
authors.affiliation: Department of Haematology, University College London, London, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Yarranton
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Lawrie
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Mackie
authors.forename: Linda
authors.initials: L
authors.lastname: Pinkoski
authors.forename: Laurence
authors.initials: L
authors.lastname: Corash
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Machin
mesh_terms: D001424:Bacterial Infections / Q000517:prevention & control; D001779:Blood Coagulation Factors / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism; D015925:Cryopreservation / Q000379:methods*; D011564:Furocoumarins; D006487:Hemostasis / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D010777:Photochemistry; D010949:Plasma / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects; D011697:Purpura, Thrombotic Thrombocytopenic / Q000628:therapy*; D014466:Ultraviolet Rays
chemical_list: D001779:Blood Coagulation Factors; D001798:Blood Proteins; D011564:Furocoumarins; C118577:amotosalen