Comparison of the Dilute Russell's Viper Venom Time by A Conventional Method with an Automated Kit Assay for the Detection of Lupus Anticoagulants

Abstract

Abstract: Lupus anticoagulants (LA) are a mixture of acquired antibodies interfering with phospholipid dependent coagulation tests. They are associated with an increased risk of thrombosis. The dilute Russell's viper venom time (dRVVT) is the most common and widely used test for the detection of LA. A number of commercial dRVVT kits are now available. This study was undertaken to compare a conventional dRVVT method with a commercial automated assay to determine their sensitivity and specificity for the identification of LA. Blood samples of 30 LA positive patients and of 30 LA negative healthy subjects by the standard method were analyzed. The conventional dRVVT method used in-house reagent detected by a semi-automated instrument (650C MDA) and the commercial dRVVT kit assay used a single set of reagent detected by an automated instrument (ACL 200). Of the 30 LA positive samples, 15 and 2 were positive by the commercial kit assay, and by the conventional method, respectively. Of the 30 LA negative samples, two gave positive results by the commercial kit assay whereas all were negative by the conventional method. The sensitivity and specificity of the conventional method were 6.67% and 100%, respectively, whereas of the commercial kit assay were 50% and 93.3%, respectively. This difference in the sensitivity of the two methods was statistically significant (p = 0.004).