title: Comparison of von Willebrand factor antigen, von Willebrand factor-cleaving protease and protein S in blood components used for treatment of thrombotic thrombocytopenic purpura.
abstract: Replacement of normal levels of von Willebrand factor-cleaving protease (VWF:CP, ADAMTS13) activity from infused plasma is important in plasma exchange (PEX) for the treatment of thrombotic thrombocytopenic purpura (TTP) patients. We have studied the VWF:CP activity, VWF multimer distribution, VWF:Ag, protein S (PS) activity and free PS antigen levels in fresh frozen plasma (FFP), cryosupernatant (CSP) and virally inactivated components treated with methylene blue/light (MB) or solvent detergent (SD) processes. VWF:CP activity was normal in all components tested and was retained following overnight storage at room temperature. CSP and SD plasma contained reduced levels of the highest molecular weight VWF multimers. Protein S activity was reduced below the normal range in SD plasma, but within the normal range for the other components tested. Virally inactivated SD- and MB-treated plasma may be an effective alternative to FFP and CSP in PEX for TTP. Reduced PS activity in SD plasma may predispose to venous thromboembolism, especially if infused in large volumes.
authors.affiliation: Haemostasis Research Unit, Department of Haematology, University College London, London, UK. hyarranton@hotmail.com
authors.forename: H
authors.initials: H
authors.lastname: Yarranton
authors.forename: A S
authors.initials: AS
authors.lastname: Lawrie
authors.forename: G
authors.initials: G
authors.lastname: Purdy
authors.forename: I J
authors.initials: IJ
authors.lastname: Mackie
authors.forename: S J
authors.initials: SJ
authors.lastname: Machin
mesh_terms: D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; D016913:Blood Component Transfusion / Q000009:adverse effects / Q000592:standards*; D001798:Blood Proteins / Q000032:analysis*; D019281:Dimerization; D006801:Humans; D008666:Metalloendopeptidases / Q000032:analysis; D010949:Plasma / Q000737:chemistry*; D010951:Plasma Exchange / Q000009:adverse effects; D017293:Protein S / Q000032:analysis; D011697:Purpura, Thrombotic Thrombocytopenic / Q000628:therapy*; D014841:von Willebrand Factor / Q000032:analysis
chemical_list: D001798:Blood Proteins; D017293:Protein S; D014841:von Willebrand Factor; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human