Human fibrinogen (FBG)

Human fibrinogen is a large, complex 340 kDa glycoprotein synthesized by hepatocytes that circulates in the blood as a soluble precursor to fibrin [7, 8]. It is composed of two sets of three polypeptide chains (Aα, Bβ, and γ) held together by disulfide bonds [5, 8]. During the final stage of the coagulation cascade, the enzyme thrombin cleaves fibrinopeptides A and B from fibrinogen, converting it into insoluble fibrin monomers that polymerize to form the structural framework of a blood clot [1, 7]. Beyond its central role in hemostasis, fibrinogen acts as an acute-phase reactant whose levels rise significantly during inflammation, and it facilitates cellular processes such as wound healing and angiogenesis through interactions with integrin receptors like αIIbβ3 on platelets [1, 12]. Therapeutically, fibrinogen is a critical target for replacement therapy in patients with congenital or acquired deficiencies (e.g., afibrinogenemia or major hemorrhage) to restore clotting capacity [2, 4, 14]. Conversely, high plasma levels are recognized as a biomarker for cardiovascular risk and COPD exacerbations, while its interaction with platelets is targeted by anti-integrin drugs to prevent pathological thrombosis [10, 12, 15].

Other names

Coagulation factor IFibrinogenFibrinFactor I

Replacement therapy to restore hemostatic levels in deficiency; enzymatic depletion (defibrinogenation) to reduce thrombotic risk; topical application for surgical hemostasis; and blockade of fibrinogen-platelet binding to inhibit aggregation.