Factor XIII

Factor XIII (FXIII) is an unusual blood coagulation factor, circulating as a heterotetramer composed of two catalytic A-subunits and two noncatalytic B-subunits. It is a plasma transglutaminase (TG), mostly associated with fibrinogen, which is activated by thrombin in the presence of calcium in the final stages of the coagulation cascade. It acts by stabilizing the clot through the covalent cross-linking of polymerized fibrin chains and the incorporation of fibrinolysis inhibitors into the fibrin clot. Genetic polymorphisms in FXIII are asso- ciated with cardiovascular diseases (CVD), including coronary artery disease (CAD), stroke, and deep vein thrombosis (DVT). FXIII deficiency leads to severe bleeding, impaired wound healing, and recurrent miscarriages. In this chapter, we review the basic functions of FXIII and focus on the most recent findings highlighting the role of FXIII in cardiovascular disease, in particular an emerging link to thrombosis. We use the detailed recommended FXIII nomenclature published in 2006 by the Scientific and Standardization sub-Committee of the International Society on Thrombosis and Haemostasis.