AN EVALUATION OF 2 COMMERCIAL TEST PROCEDURES FOR THE DETECTION OF LUPUS ANTICOAGULANT

The authors have evaluated two commercial assays for lupus anticoagula nts (LA), the DVV test + DVV confirm (American Diagnostica, Greenwich, CT) and the PTT-LA + Staclot LA (Diagnostica Stage, Asnieres-Sur-Sein e, France). The assays were compared with a previously described quant itative, semi-automated, and computer-assisted test, which is based on two assays, using the activated partial thromboplastin time (APTT) an d the Russell's viper venom time (RVVT), respectively. Thirty well-cha racterized LA-positive and 30 LA-negative plasma samples were used to test the commercial assays. In some samples, both commercial tests fai led to detect weak or moderately strong LAs. The sensitivity was 80% f or the DVV test + DVV confirm and 67% for the PTT-LA + Staclot LA. How ever, by applying both the two commercial tests to all plasma samples, 29 of 30 LB-positive plasma samples were diagnosed (sensitivity 97%), No false positive test results were found (specificity 100%).