Coagulation factor V (F5), Coagulation factor VIII (F8), Coagulation factor XI (F11), and Coagulation factor XIII (F13) (F5, F8, F11, F13)

Coagulation factors V, VIII, XI, and XIII are a specific group of proteins within the blood coagulation cascade that are primarily activated by thrombin (Factor IIa) to amplify and stabilize the formation of a blood clot [5, 6, 9]. Factors V (Proaccelerin) and VIII (Antihemophilic factor) function as essential non-enzymatic cofactors that dramatically accelerate the activation of prothrombin and factor X, respectively, facilitating a rapid burst of thrombin generation [1, 3, 10]. Factor XI (Plasma thromboplastin antecedent) is a serine protease that sustains this process through a feedback loop in the intrinsic pathway, while Factor XIII (Fibrin-stabilizing factor) is a transglutaminase that cross-links fibrin strands to provide mechanical stability and resistance to fibrinolysis [1, 13, 14, 17]. Deficiencies in these factors are associated with significant bleeding disorders, most notably Hemophilia A (Factor VIII deficiency) and Hemophilia C (Factor XI deficiency), which are managed through replacement therapies or bypass agents [1, 10]. Conversely, these factors—particularly Factor XI—have become major targets for next-generation anticoagulants, such as abelacimab and milvexian, which aim to prevent pathological thrombosis with a significantly lower risk of bleeding compared to traditional anticoagulants [2, 7, 13, 18]. The therapeutic landscape for these factors continues to evolve, with a focus on improving safety profiles and reducing the burden of treatment for patients with both hereditary deficiencies and thrombotic risks [7, 12, 15].

Other names

Coagulation factors V, VIII, XI, XIIIThrombin-activated coagulation factorsProaccelerinAntihemophilic factorPlasma thromboplastin antecedentFibrin-stabilizing factor

Replacement of deficient coagulation factors, inhibition of protease activity to prevent thrombus formation, and mimetic activity to substitute for missing cofactors.