Sta stachrom at 3

Anti-Xa activity was assessed by quantifying residual factor Xa activity by cleavage of a chromogenic substrate (STA-Liquid Anti Xa, Diagnostica Stago, Asnieres, France), reference value <0.05 kIU/L. Activated partial thromboplastin time (aPTT) was measured with STA APTT reagent containing cephalin as a source of the phospholipids and silica as a particulate activator (reference range 30–42 seconds). Determination of thrombin time (TT) was done by standard commercial STA Thrombin 2 test (Diagnostica Stago, Asnieres, France), adding thrombin to patient plasma and measuring the clotting time (reference range 14–21 seconds). Antithrombin was measured by chromogenic substrate method (STA-STACHROM AT III, Diagnostica Stago, Asnieres, France) (reference range 0.8–1.2 kIU/L). All analyses were performed on STA-R coagulometer (Diagnostica Stago, Asnieres, France).

Plasma AT activity levels were determined by amidolytic heparin cofactor assay with chromogenic substrate CBS 61.50 (STA-STACHROM ATIII; Diagnostica stago, France). AT antigen levels were determined by latex immunoassay (LIATEST ATIII; Diagnostica stago, Asnieres, France). Prothrombin time (PT), thromboplastin time (TT) and activated partial thromboplastin time (APTT) were performed using kits from Diagnostiga STAGO. Plasma levels of PC and PS were measured by enzyme-linked immunosorbent assay and the kits used were Asserachrom sEPCR ELISA from Diagnostica Stago (Asnières, France). Homocysteine (SHO) and Beta-2 glycoprotein (β-2 gp) levels were measured by enzyme immunoassay by using kits from AXIS-SHIELD, Scotland and GA Generic assays GmbH, Germany respectively. All the assays were carried out as per the manufacturer’s protocol.