Current understanding in diagnosis and management of factor XIII deficiency

Factor XIII or «fibrin-stabilizing factor،» is a transglutaminase circulates in the blood circulation as a hetero tetramer with two catalytic A subunits and two carrier B subunits. This important coagulation factor has a crucial role in clotting cascade and produces strong covalent bonds between soluble formed fibrin monomers during coagulation. This stable cross linked fibrin strands are resistant to degradation by the fibrinolytic system that enables the body to stop potential bleeding episodes. In the absence or severe decrease of factor XIII، although the clot is formed، but is rapidly degraded by the fibrinolytic system، and delayed bleeding occurs. Factor XIII deficiency is an extremely rare bleeding disorder with estimated incidence of 1/2-3000، 000 in the general population. Presumptive diagnosis of factor XIII deficiency was by clot solubility test in 5M urea or 1% monochloroacetic acid environments. In patients with abnormal screening clot solubility test، the disease can be confirmed by more specific tests such as quantitative factor XIII activity assay and FXIIIAg assay. After diagnosis of disease all patients with severe factor XIII deficiency (<1 U/dl) should receive prophylactic substitution therapy with fresh frozen plasma (FFP) and cryoprecipitate as traditional choices or purified concentrate of blood coagulation factor XIII (Fibrogammin P) in order to control severe and life-threatening clinical complications of factor XIII deficiency.