EVALUATION OF A NEW SCREENING ASSAY PROC(R) GLOBAL FOR IDENTIFICATIONOF DEFECTS IN THE PROTEIN-C PROTEIN-S ANTICOAGULANT PATHWAY

In the present study a new assay, ProC(R) Global, globally estimating the activity of the main plasma components of anticoagulant protein C/ protein S pathway, was evaluated with respect to test characteristics and its sensitivity in the detection of deficiency states of protein C and protein S and of increased aPCR. In the ProC(R) Global assay proc edure protein C is activated in patient's plasma by an activator reage nt (venom from agkistrodon contortrix). The extent of the prolongation of a sample's aPTT, caused by the activation of protein C, is taken a s a measure for its anticoagulant capacity. Ninetyeight patients with one of the above mentioned defects were investigated. Decreased plasma protein C activity and increased aPCR were detected with a sensitivit y of 1.0, while only 11 of 14 patients with decreased levels of free p rotein S antigen showed abnormal results in the ProC(R) Global assay ( sensitivity=0.79). The test can be used in heparinized samples up to 1 .0 anti Xa U/ml heparin (UFH and LMWH). When samples from patients on oral anticoagulant treatment are prediluted with factor V deficient pl asma the test is sensitive for increased aPCR. (C) 1997 Elsevier Scien ce Ltd.