Abstract Number: PB0310
Meeting: ISTH 2021 Congress
Theme: Diagnostics and OMICs » Biomarkers of Thrombosis and Hemostasis
Background: Direct oral anticoagulants (DOACs) may interfere with lupus anticoagulant assays (LAC) and cause falsely positive results. We have previously shown that the MRX PT DOAC test can be used to detect interfering DOACs in thrombophilia investigations (PB0598 ISTH 2020). For this extended and ongoing study, both laboratory data and clinical records are available. Thus anticoagulant treatment can be checked.
Aims: To evaluate if MRX PT DOAC can detect DOACs at concentrations interfering with coagulation analysis in thrombophilia investigations.
Methods:
- MRX PT DOAC was analyzed at the time of thrombophilia investigation. Positive LA-dRVVT samples were reanalyzed after addition of DOAC-STOP. Clinical records were reviewed for ongoing anticoagulant treatment.
- The literature was reviewed for concentrations at which DOACs interfere with LAC tests with focus on LA-dRVVT.
- Data was collected from patient samples where both DOAC concentration and MRX PT DOAC were available to make sure that MRX PT DOAC detects DOACs at concentrations known to interfere.
- The study was approved by the ethical committee, approval No 2020-04525.
Results: At present, 232 patients are evaluated, 18 of these were treated with DOACs (ten with apixaban, eight with rivaroxaban). All apixaban patients had a negative LA-dRVVT test. In the rivaroxaban patients the LA-dRVVT test was falsely positive in two patients due to rivaroxaban interference, in another four patients the LA-dRVVT test was truly positive while LA-dRVVT was negative in the final two. MRX PT DOAC detected 100 % of falsely positive LA-dRVVT samples.
Hillarp et al 2020, reported interference of LAC test by rivaroxaban and apixaban at concentrations over 50 µg/L and 350 µg/L, respectively.
Results confirmed that MRX PT DOAC detects DOACs at concentrations where interference with LAC test could be an issue.
Conclusions: Our results indicate that the screening method MRX PT DOAC can detect the presence of interfering DOACs in patient samples during thrombophilia investigation.
To cite this abstract in AMA style:
Lindahl T, Lund M, Arbring K, Onelöv L. Use of MRX PT DOAC in a Routine Laboratory Setting for Detection of Interfering DOACs in Thrombophilia Investigation [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/use-of-mrx-pt-doac-in-a-routine-laboratory-setting-for-detection-of-interfering-doacs-in-thrombophilia-investigation/. Accessed March 22, 2024.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/use-of-mrx-pt-doac-in-a-routine-laboratory-setting-for-detection-of-interfering-doacs-in-thrombophilia-investigation/