Coagulation factor XIII (FXIII) (FXIII)

Coagulation factor XIII (FXIII) is a heterotetrameric pro-enzyme consisting of two A-subunits and two B-subunits, serving as the terminal enzyme in the coagulation cascade (UniProt P00488). Upon activation by thrombin and calcium, the A-subunits function as a transglutaminase that creates covalent epsilon-(gamma-glutamyl)lysine cross-links between fibrin strands, significantly increasing the mechanical strength and proteolytic resistance of the blood clot (StatPearls, NBK539774). FXIII also plays essential roles in wound healing by cross-linking proteins like fibronectin to the clot and is vital for maintaining pregnancy through its interaction with the extracellular matrix at the maternal-fetal interface (PubMed, 21547399). Clinical deficiency of FXIII results in a severe bleeding disorder characterized by delayed umbilical cord bleeding, intracranial hemorrhage, and poor wound healing (NIH, GARD:6417). Therapeutic management involves replacement with recombinant products like catridecacog or plasma-derived concentrates to restore hemostatic function (DrugBank, DB09035). Beyond its role in deficiency, FXIII is being investigated as a potential target for novel anticoagulants to prevent thrombosis without significantly impairing primary hemostasis (PubMed, 24683403). The enzyme's activity is typically monitored using specialized assays, as standard screening tests like prothrombin time often fail to detect its deficiency (StatPearls, NBK539774).

Other names

Fibrin-stabilizing factor (StatPearls)Laki-Lorand factor (PubMed)Fibrinoligase (UniProt)Transglutaminase plasma-chainFXIII

Replacement of the deficient enzyme to restore fibrin cross-linking and clot stability (DrugBank).