Stachrom plasminogen

The coagulation tests used to screen for HT were PC activity (Stachrom^® Protein C, Diagnostica Stago, Asnières, France), PS free Ag (Liatest^® Free Protein S, Diagnostica Stago), AT activity (Stachrom^® AT III, Diagnostica Stago), and plasminogen activity (Stachrom^® Plasminogen, Diagnostica Stago), per the international guidelines [19 (link)]. All coagulation tests were performed on the STA^®-Evolution Coagulation Analyzer. Reference ranges were determined according to our institutional data. Whenever possible, coagulation tests were repeated 2 weeks after the discontinuation of anticoagulation therapy if results at the time of diagnosis showed low levels of multiple NAs or if tests with abnormal results were performed under anticoagulant use.

Venous blood samples were drawn with minimal stasis using atraumatic venipuncture at 08.00–11.0 AM, after an overnight fast. All measurements were performed in VTE patients after 3 months of anticoagulant therapy since the index event. Patients were drawn >24 hours since the last dose of NOACs. Complete blood count, glucose, creatinine, lipid profiles, and INR were assayed by routine laboratory techniques. High-sensitivity C-reactive protein (hs-CRP) was determined by immunoturbidimetry (Roche Diagnostics GmbH, Mannheim, Germany). Plasma D-dimer was measured with the Innovance D-dimer assay (Siemens, Marburg, Germany). Plasma α₂-antiplasmin and plasminogen were measured by chromogenic assays (STA Stachrom antiplasmin and Stachrom plasminogen, Diagnostica Stago, Asniéres, France). Plasma PAI-1 antigen was measured by an ELISA kit (Hyphen). For evaluation of clot properties and thrombin generation, venous blood samples were mixed with 3.2% trisodium citrate (vol/vol, 9 : 1), then centrifuged at 2000 × g for 10 min within 30 minutes of the draw, and stored in aliquots at -80°C until analysis. All measurements were performed by technicians blinded to the origin of the samples. Intra-assay and interassay coefficients of variation were 5-7%.