Factor X Activity Test

Factor X activity testing is a functional (coagulation) test that measures the functional activity of coagulation factor X (Factor X) in blood plasma, expressed as a percentage of normal activity. Factor X is a vitamin K-dependent protein that forms the junction between the extrinsic and intrinsic pathways of the coagulation cascade, converting them into the final common pathway. It is used to diagnose congenital (Stuart-Brower disease) or acquired factor X deficiency.