Fibrinogen (FBG) (FBG)

Fibrinogen is a 340 kDa hexameric glycoprotein synthesized in the liver, consisting of two sets of alpha, beta, and gamma chains (FGA, FGB, FGG) [UniProt, 2024]. It is a key player in the coagulation cascade, where it is converted by thrombin into fibrin, the primary protein component of blood clots [StatPearls, 2023]. This conversion involves the cleavage of fibrinopeptides A and B, allowing fibrin monomers to polymerize into a stable meshwork that traps platelets and red blood cells [PubMed, 2021]. Beyond hemostasis, fibrinogen functions as an acute-phase reactant, increasing during inflammation and contributing to tissue repair and angiogenesis [NCBI, 2022]. In clinical medicine, fibrinogen is a therapeutic target for replacement in patients with congenital or acquired deficiencies (e.g., afibrinogenemia) and is the substrate for thrombolytic drugs that dissolve pathological thrombi in stroke or myocardial infarction [DrugBank, 2024]. Elevated levels are also recognized as a biomarker for increased cardiovascular risk and systemic inflammation [PubMed, 2020].

Other names

Factor ICoagulation factor IFibrinFibrinogen complex

Fibrinogen serves as the precursor to fibrin; drugs like thrombin convert it to form clots, while thrombolytics like alteplase indirectly target it by activating plasmin to degrade the fibrin mesh. Defibrinogenating agents like ancrod directly cleave fibrinogen to deplete its plasma levels, and replacement therapies provide exogenous fibrinogen to restore hemostatic function [StatPearls, 2023; PubChem, 2024].