title: Factor VIIa-antithrombin complex: a possible new biomarker for activated coagulation.
abstract: The activation of the extrinsic coagulation pathway occurs after endothelial injury when the tissue factor (TF), a transmembrane protein located outside the vasculature, binds factor VII (FVII) or activated FVII (FVIIa). Once formed, the TF-VIIa complex activates both factor IX and X and initiates the coagulation process. The TF-VIIa complex is inhibited by both TF pathway inhibitor (TFPI) and antithrombin (AT). The interaction between TF-VIIa and AT induces FVIIa-AT complex formation, which is released into the plasma. Because AT reacts with FVIIa only when it is bound to TF, the circulating levels of FVIIa-AT reflect the degree of exposure of TF to blood. Preliminary clinical studies have shown higher plasma levels of FVIIa-AT complex both in patients with a prior arterial or venous thrombotic event. Increased plasma levels of FVIIa-AT have also been reported in a number of other prothrombotic conditions - antiphospholipid antibodies, solid and hematological malignancies, pre-eclampsia (PE), obesity and cardiac surgery. However, most of the studies published so far are retrospective and with a limited sample size. Larger prospective clinical studies are needed to confirm these findings and to assess the prognostic role of this possible new biomarker for activated coagulation.
authors: Luca
authors: L
authors: Spiezia
authors: Elena
authors: E
authors: Campello
authors: Fabio Dalla
authors: FD
authors: Valle
authors: Barry
authors: B
authors: Woodhams
authors: Paolo
authors: P
authors: Simioni
mesh_terms: D000991:Antithrombins / Q000097:blood* / Q000378:metabolism; D015415:Biomarkers / Q000097:blood* / Q000378:metabolism; D001777:Blood Coagulation; D004797:Enzyme-Linked Immunosorbent Assay; D015942:Factor VIIa / Q000032:analysis* / Q000378:metabolism; D005260:Female; D006801:Humans; D011225:Pre-Eclampsia / Q000097:blood; D011247:Pregnancy; D013927:Thrombosis / Q000097:blood*; D020246:Venous Thrombosis / Q000097:blood
chemical_list: D000991:Antithrombins; D015415:Biomarkers; D015942:Factor VIIa