Description: Coagulation can be initiated either by the intrinsic or extrinsic pathway, but both mechanisms converge in the coagulation cascade. Both pathways are complex and involve numberous proteins known as coagulation factors.
Coagulation Factors that can be analysed with this kit:
A glycoprotein present in plasma that is converted into thrombin by extrinsic thromboplastin during the second stage of blood clotting. Also called factor II.
A glycoprotein serpine that inactivates several enzymes of the coagulation system. Inhibition of coagulation occurs predominantly by inactivitng factors Xa, Ixa and XIIa. A lowered level of Antithrombin correlates with an increased risk of thrombosis.
Is a part of the contact activation phase of the intrinsic coagulation pathway. Factor XI is produced by the liver and circulates as a homodimer in ist inactive form. An acquired factor XI deficiency which is also know as haemophilia c, can result from liver diseases, blood loss and consumptive coagulopathies. Factor Xia activates factor IX by selective cleavage. Factor Ixa, in turn, activates factor X. Autoimmune diseases like lupus erythematosus and substitution therapies can result in the formation of inhibitor against factor XI. Raised factor XI levels seem to play a role as risk factor for thrombosis.
Factor XII is the main enzyme of the contact activation of the intrinsic coagulation pathway. It not only plays a role in activation of coagulation (factor XI) but also in activation of the fibrinolytic system and the kallikrein-kinin system. An acquired factor XI deficiency can result from liver diseases, consumptive coagulopathies, lupus anticoagulants, nephrotic syndrome and tissue rejection in transplantations. People with deficiences however not always show bleeds and normally require no treatment. Elevated factor XII levels can be seen during pregnancy and use of oral contraceptiva.