Abstract Number: PB0329
Meeting: ISTH 2021 Congress
Background: Dilute Russell’s viper venom time (dRVVT) is one of the recommended assays for lupus anticoagulant (LA) detection. However, reagents variability affects diagnostic efficacy in LA testing and it is not clear whether all dRVVT reagents may be considered equivalent.
Aims: The objective of this study was to evaluate the analytical performances of a new formulation DVVtest/DVVconfirm (Horiba Medical) performed with the Yumizen G800 analyzer and to compare it with a currently available dRVVT assay performed on a STAR Max analyzer.
Methods: Within-run and between-run imprecision of DVVtest and DVVconfirm were evaluated using the low- and high-quality control plasmas (Latrol Normal and Abnormal, Horiba Medical). DVVtest/DVVconfirm were evaluated for 62 healthy controls, 20 patients who met clinical criteria of antiphospholipid syndrome (APS) and were LA-positive when tested with Stago dRVV Screen/Confirm, and 39 patients with an autoimmune disease but without clinical criteria for APS and LA-negative with Stago dRVV Screen/Confirm. LA was considered positive if the screen and LA ratio were positive (cut-off provided by the manufacturers).
Results: Within- and between-run coefficients of variation were consistent with manufacturer’s data (Table 1). Two controls, who were LA-negative with Stago dRVV reagents, had a positive LA testing with DVVtest/DVVconfirm. Two patients with clinical criteria for APS and LA-positive with Stago dRVV Screen/Confirm had a negative LA testing performed with DVVtest/DVVconfirm. For DVVtest/DVVconfirm assay performed on the Yumizen G800 analyzer, sensitivity, specificity and negative predictive value were of 90%, 97% and 97.8%, respectively. Among the 39 patients who were LA-negative with Stago dRVV reagents, 6 were found positive with DVVtest/DVVconfirm including 2 patients with systemic lupus erythematosus and 2 patients with positive anticardiolipin and anti-beta 2 glycoprotein I antibodies, raising the question of the sensitivity/specificity of these assays.
| n | Mean value (seconds) | SD (seconds) | CV (%) | CV (%) manufacturer | |||
| DVVtest | Within-run | LAtrol Abn | 13 | 107.9 | 1.6 | 1.5 | 3.3 |
| LAtrol N | 13 | 49.1 | 0.5 | 0.9 | 2.0 | ||
| Between-run | LAtrol Abn | 25 | 97.8 | 3.9 | 4.0 | 5.6 | |
| LAtrol N | 25 | 40.7 | 1.5 | 3.7 | 6.8 | ||
| DVVconfirm | Within-run | LAtrol Abn | 13 | 48.7 | 0.8 | 1.7 | 3.6 |
| LAtrol N | 13 | 39.9 | 0.8 | 1.9 | 1.8 | ||
| Between-run | LAtrol Abn | 25 | 48.8 | 2.2 | 4.5 | 4.7 | |
| LAtrol N | 25 | 37.4 | 0.4 | 1.0 | 2.3 |
Imprecision of the DVVtest and DVVconfirm assays. Abn: abnormal; N: normal.
Conclusions: The analytical performances of DVVtest and DVVconfirm reagents make it suitable for LA detection in clinical laboratories.
To cite this abstract in AMA style:
Talon L, Fourneyron V, Tardieu M, Trapani A, Sinegre T, Lebreton A. Newly Developed Dilute Russell’s Viper Venom Reagents for Lupus Anticoagulant Detection [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/newly-developed-dilute-russells-viper-venom-reagents-for-lupus-anticoagulant-detection/. Accessed November 29, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/newly-developed-dilute-russells-viper-venom-reagents-for-lupus-anticoagulant-detection/