ProC global: A new automated screening assay for the evaluation of total function of the protein C system

Protein C (PC) pathway represents a major physiologic inhibitory mechanism regulating the coagulation cascade. A new automated functional screening as say (ProC Global) for the evaluation of the PC-system was tested to define its ability to identify patients with known inherited defects such as facto r V (FV) Leiden mutation and PC and protein S (PS) deficiency. A total of 2 49 patients who were symptomatic or asymptomatic for previous venous thromb oembolism (VTE) were evaluated, 50 of whom had FV Leiden mutation, 36 had P C deficiency, and 34 had PS deficiency. One hundred healthy subjects were a lso tested, as well as 40 blood donors of both sexes in whom coagulation ab normalities were not found. Results of ProC Global test were expressed as n ormalized ratio (NR) and values below an established cut-off level were con sistent with a positive test. ProC Global was positive in all 50 patients w ith the FV Leiden mutation (mean NR = 0.59; range, 0.37 to 0.69). ProC Glob al correctly identified 32 of 36 (89%) PC defects (mean NR = 0.63; range, 0 .34 to 1.21) and 25 of 34 (73.5%) PS defects (mean NR = 0.76; range, 0.5 to 1.23). Overall, 92.5% of hereditary defects of the PC system considered in this study were identified by ProC Global test. ProC Global exhibited NR a bove cut-off level in all 40 blood donors without coagulation defects. ProC Global is a new automated screening test with some diagnostic potential in identifying patients with defects of the PC system. However, ProC Global i n its current form cannot substitute the assay of each single component of this inhibitory system in the daily screening for thrombophilia.