Pro CR Global: An Effective Screening Test for Thrombophilia

Abstract

In the present study, the Pro CR Global test was evaluated as a screening test for estimation of the activity of the main plasma components of the anticoagulant protein C (PC) / protein S (PS) pathway; 300 patients with a history of thrombosis were investigated for Pro CR Global. It was positive in 74 patients. Tests for estimation of PC, PS, activated protein C resistance (APCR), and lupus anticoagulant (LAC) were performed in all the patients with abnormal Pro CR Global and in 10 patients with normal Pro CR Global. In all, 66 of the 74 patients had a defect in PC/PS/APCR or LAC; 18 patients had both PC and PS deficiency, 25 had PS deficiency alone, 10 had PC deficiency alone, one had APCR alone, eight had PS, PC deficiency with APCR, and four had PS deficiency with APCR. In the 10 patients who tested negative with the Pro CR Global test, PC, APCR, and LAC were negative in all. However, PS deficiency was seen in two of them. The sensitivity and specificity of Pro CR Global, calculated with respect to positivity of PC, PS, LAC, or APCR as the gold standard, were 97% and 50%, respectively. The diagnostic accuracy of the assay was 88.1%. It is thus recommended that Pro CR Global can be used effectively as a screening test to detect abnormality in the PC/PS/APCR/LAC pathway. © 2003 Wiley-Liss, Inc.