LABORATORY SCREENING OF THROMBOPHILIA - EVALUATION OF THE DIAGNOSTIC EFFICACY OF A GLOBAL TEST TO DETECT CONGENITAL DEFICIENCIES OF THE PROTEIN-C ANTICOAGULANT PATHWAY

Clinical laboratories are at present confronted with increasing demand s for thrombophilia work-up, which may seriously overwhelm their capac ity. Recently methods able to investigate the protein C anticoagulant pathway globally have been proposed In this study we investigated the reliability of one such method for its ability to detect patients with known defects of the pathway by testing plasmas from patients with th e FVQ(506) mutation, with congenital protein C, protein S or antithrom bin deficiencies, and patients with previous history of thrombosis, bu t no identifiable defects. The results show that the new global test f ulfils the requirements for congenital protein C deficiency and activa ted protein C resistance associated with the FVQ(506) mutation, which account for more than half of the congenital defects found in thrombop hilia. However, congenital protein S deficiency very often remains und etected by this test. Improvement of sensitivity toward this component of the protein C anticoagulant pathway would enroll the global test a s a suitable candidate to explore the pathway. Since antithrombin, whi ch also remains undetected by this test, is an additional important ri sk factor for venous thrombosis, devoting time and effort to developin g global tests able to detect defects in both the antithrombin and pro tein C pathways is warranted. Blood Coag Fibrinol 9:485-489 (C) 1998 L ippincott Williams & Wilkins.