Coagulation Factor XI, also known as plasma thromboplastin antecedent (PTA), is a protein that plays a crucial role in the blood clotting process. It is one of the numerous coagulation factors involved in the clotting cascade, which ultimately leads to the formation of stable blood clots to prevent excessive bleeding.
Coagulation Factor XI is produced in the liver and circulates in the blood as an inactive precursor. Upon injury or damage to blood vessels, this precursor is activated by other coagulation factors in the presence of calcium ions.
Once activated, Coagulation Factor XI initiates a complex series of enzymatic reactions known as the intrinsic pathway. It acts by activating Coagulation Factor IX, another important clotting factor. This activation cascade ultimately leads to the production of thrombin, which converts fibrinogen to fibrin, forming the structure of a blood clot.
Defects or deficiencies in Coagulation Factor XI can lead to a bleeding disorder called Hemophilia C or Rosenthal syndrome. Patients with this condition may experience prolonged bleeding, particularly after surgery or trauma.
Additionally, certain genetic mutations in Coagulation Factor XI can result in an increased risk of venous thrombosis, where blood clots develop within veins. This highlights the dual role of Coagulation Factor XI in both clotting and bleeding processes.
In summary, Coagulation Factor XI is an essential protein involved in the intricate process of blood clotting, necessary for maintaining hemostasis and preventing excessive bleeding.
