Cross-linked fibrin (XLF)

Cross-linked fibrin is the insoluble protein matrix that forms the structural backbone of a blood clot. It is generated through the proteolytic cleavage of soluble fibrinogen by thrombin, followed by the polymerization of fibrin monomers and their subsequent stabilization via covalent cross-linking by activated Factor XIII (Factor XIIIa) (StatPearls, 2023). This process is essential for physiological hemostasis and wound healing, providing a scaffold for cellular infiltration and tissue repair. However, the aberrant formation of cross-linked fibrin is a central feature of thrombotic diseases, including myocardial infarction, ischemic stroke, and venous thromboembolism (PubMed, 2022). Therapeutic targeting of cross-linked fibrin primarily involves thrombolytic agents, such as alteplase and tenecteplase, which facilitate the conversion of plasminogen to plasmin, leading to the enzymatic degradation of the fibrin mesh (DrugBank, 2024). Additionally, because cross-linked fibrin contains unique epitopes like D-dimer, it serves as a critical biomarker for diagnosing active coagulation and is a target for molecular imaging techniques (Mayo Clinic, 2023).

Other names

Insoluble fibrinFibrin polymerStabilized fibrinFibrin IIFibrin mesh

Thrombolytic drugs typically bind to the fibrin matrix and facilitate the activation of plasminogen into plasmin, which then enzymatically cleaves the cross-linked fibrin strands into soluble fragments (fibrinolysis).