In vitro characterization of recombinant factor VIII concentrates reveals significant differences in protein content, activity and thrombin activation profile. (18th December 2012)

• Record Type: Journal Article
• Authors: Pahl, S.; Pavlova, A.; Driesen, J.; Müller, J.; Pötzsch, B.; Oldenburg, J.
• Is Part Of: Haemophilia. Volume 19:Number 3(2013:May)
• Page Start: 392
• Page End: 398
• Publication Date: 2012-12-18
• Subjects: Hemophilia -- Periodicals; 616.1572005
• DOI: 10.1111/hae.12076
• Languages: English
• ISSNs: 1351-8216

Abstract

<abstract abstract-type="main" id="hae12076-abs-0001"> <title>Summary</title> <p>Recombinant factor VIII (rFVIII) concentrates differ due to cell lines, culture conditions, presence of the B domain and authorized potency assays. This study characterizes three commercially available rFVIII concentrates: a second‐generation full length (<italic>A</italic>), a third‐generation full length (<italic>B</italic>) and a third‐generation B domain‐deleted (BDD) product (<italic>C</italic>). rFVIII concentrates were characterized for FVIII activity (FVIII:C) by one‐stage clotting and chromogenic assays, FVIII antigen (FVIII:Ag), thrombin activation profile and FXa‐generation assay. The rFVIII concentrates exhibited significant differences with regard to FVIII:C, FVIII:Ag and thrombin activation profile. <italic>Product A</italic> had significantly greater FVIII:C and FVIII:Ag relative to the measured values of <italic>products B and C</italic>. In addition, <italic>product A</italic> demonstrated faster and more complete activation by thrombin than the two others. BDD <italic>product C</italic> had the slowest measured thrombin activation rate. <italic>Product A</italic> exhibited a greater <italic>in vitro</italic> FXa generation than <italic>products B and C</italic>. We found no differences in FXa generation among all three products when FXa generation was normalized for FVIII:Ag. The greater FVIII:C and FVIII:Ag values for <italic>product A</italic> compared with that for <italic>products B and C</italic> are due to application of different authorized potency assays (one‐stage assay for <italic>A vs</italic>. chromogenic assay for <italic>B and C</italic>). The variation in thrombin activation profiles may arise from differences in cell line‐dependent posttranslational modifications of the various recombinant proteins.</p> </abstract>