Thromb Haemost 2002; 88(04): 583-586
DOI: 10.1055/s-0037-1613259
Review Article
Schattauer GmbH

Laboratory Diagnosis of Lupus Anticoagulants for Patients on Oral Anticoagulant Treatment

Performance of Dilute Russell Viper Venom Test and Silica Clotting Time in Comparison with Staclot® LA
Armando Tripodi
1  Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Milano, Italy
,
Veena Chantarangkul
1  Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Milano, Italy
,
Marigrazia Clerici
1  Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Milano, Italy
,
Pier Mannuccio Mannucci
1  Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Milano, Italy
› Author Affiliations
Further Information

Publication History

Received 25 February 2002

Accepted after revision 28 May 2002

Publication Date:
09 December 2017 (online)

Summary

The detection of lupus anticoagulant (LA) in plasmas from patients on oral anticoagulants is problematic because of their prolonged clotting times. Mixing of patients and normal plasmas prior to testing for LA is employed to overcome this problem. We investigated the diagnostic efficacy of silica clotting time (SCT) and dilute Russell viper venom test (dRVVT) performed at low and high phospholipid concentrations, to diagnose LA in patients on oral anticoagulants, in comparison with Staclot® LA (Stago) performed with and without hexagonal phospholipids and normal plasma. Case materials were 114 filtered plasmas from patients on oral anticoagulants with (n = 62) and without (n = 52) the antiphospholipid syndrome. Plasmas were considered LA-positive when Staclot® LA (taken as the “gold standard”) was diagnostic for LA. Forty-four plasmas were positive with Staclot® LA. Forty and 39 of these were also positive with SCT and dRVVT (sensitivity relative to Staclot® LA was 91% and 89%, respectively). Seventy plasmas were negative with Staclot® LA. Three of these were positive with both SCT and dRVVT (specificity relative to Staclot® LA was 96%). Kappa values for measure of agreement were 0.87 and 0.85 (p <0.001), respectively. In conclusion, SCT and dRVVT performed at low and high phospholipid concentrations without normal plasma can be considered as reliable as Staclot® LA peformed with hexagonal phospholipids and normal plasma to diagnose LA in patients on oral anticoagulants. Advantages of SCT and dRVVT over Staclot® LA are easy automation, no need for normal plasma and relatively low cost.