Use

This test is useful for diagnosing hemophilia A, diagnosing von Willebrand disease when measured with von Willebrand factor antigen and activity, diagnosing acquired deficiency states, investigating prolonged activated partial thromboplastin time, and monitoring infusions of factor VIII replacement during interventional procedures and prophylactic infusions. It is not useful for inferring carrier status in suspected female carriers of hemophilia A unless the activity is less than 50% of normal. Factor VIII is a coagulation cofactor in the intrinsic coagulation pathway, primarily synthesized in the liver. Congenital factor VIII deficiency causes hemophilia A, which occurs in 1 in 10,000 male births and is inherited in a recessive sex-linked manner on the X chromosome.