ProC Global: the first functional screening assay for the complete protein C pathway.

In clinical practice, venous thromboembolic complications are much more frequent than bleeding disorders. In fact, disturbances within the protein C pathway due to coagulation factor V (FV) Leiden mutation and deficiency of protein C or protein S are the most frequent abnormalities in hereditary thrombophilia. Furthermore, acquired dysfunctions of the protein C system may predispose the single individual to an increased thrombotic risk. A routine-suited screening assay that would allow the monitoring of the proper interplay of factors in the protein C pathway could add an important factor to the basic coagulation profile. This consists of the prothrombin time and of the activated partial thromboplastin time, which currently allow only a screening for increased risk for bleeding but not for venous thromboembolism. A new functional screening test for the protein C system such as the presented ProC Global should therefore facilitate detection of FV Leiden as well as deficiency of protein C and protein S. The results of the present evaluation indicate that ProC Global is highly sensitive to activated protein C resistance/FV Leiden (100%) and protein C deficiency (90%) and sensitive to protein S deficiency (63%). Furthermore, the assay gives a quantitative measure of the net potential of the protein C pathway in relation to the intrinsic procoagulant system. The use of this assay for a prospective assessment of thromboembolic risk is the subject of current studies.