Factor VIII, Plasma

Factor VIII (anti-haemophilic factor) is a trace plasma glycoprotein, which plays a central role in normal blood coagulation. Most factor VIII circulates as a complex with von Willebrand factor (vWF), the levels of which are dependent on factors such as blood group (O-group being associated with low and AB being associated with high factor VIII levels respectively) and endothelial stimulation. The gene that codes for factor VIII is at the tip of the long arm of the X chromosome. The major source of factor VIII appears to be the hepatocytes, but other sites of production exist and may play an important role in the production of factor VIII. Factor VIII acts as a cofactor in the activation of factor X by activated factor IX. In the presence of ionic calcium and a phospholipid surface, the rate of factor X activation is increased more than 10,000-fold by factor VIII. See Also von Willebrand (Factor VIII Related Ag), Plasma

Congenital deficiency of factor VIII occurs in patients with haemophilia A, von Willebrand’s disease, and combined factor deficiencies, such as deficiency of factors VIII and V. Increased levels of factor VIII are found in coronary artery disease, exercise, hyperthyroidism, hypoglycaemia, pregnancy, and surgery. In addition, factor VIII levels are increased with the administration of certain drugs including oral contraceptives.

2 ml Citrate Plasma Frozen

von Willebrand & Factor VIII:C are the components of factor VIII.

By Report