Abstract Number: PB0632
Meeting: ISTH 2020 Congress
Background: Despite known effects of direct oral anticoagulants (DOAC) on plasma-based assays for thrombophilia screening or coagulation factors (Kitchen, 2014), these tests are frequently requested by clinicians for DOAC patients. Several studies have investigated the use of a simple charcoal product called DOAC-Remove (5-Diagnostics, Quadratech, Switzerland) to eliminate DOAC interference from patient samples undergoing coagulation tests (Cox-Morton, 2019; Jourdi , 2019).
Aims: To describe our haemostasis laboratory experience with DOAC-Remove in LA-positive samples of DOAC-patients.
Methods: This preliminary single-centre study included 10 LA-negative subjects, 10 LA-positive patients not on a DOAC or any other anticoagulant and 16 LA-positive patients treated with a DOAC. The presence of LA was determined according to guidelines of the International Society on Thrombosis and Haemostasis (ISTH), using the diluted Russell Viper Venom time (dRVVT) and the Silica Clotting Time (SCT) integrated tests. PT, aPTT and LA tests were measured on ACL Top 700 analyzer (Instrumentation Laboratory, MA, USA). The results were expressed on normalized ratios and our cut-off values were 1.2 for dRVVT and 1.3 for SCT. All samples were treated with DOAC-Remove used according to the manufacturer’s instructions. DOAC removal was confirmed by anti-Xa or thrombin time as appropriate, DOAC levels and the effect on basic coagulation tests.
Results: After adding DOAC-Remove to LA-positive plasma of DOAC patients, 11 of 16 (68.75%) tested negative for LA. Interferences in PT and aPTT were observed in 13 DOAC patients, 10 (76.92%) of which were neutralized. There were 5 (31.25%) true LA-positive samples. No effect was seen in LA-negative and LA-positive subjects not on a DOAC (Figure 1).
Conclusions: In our experience, false positivities of LA in DOAC patients can be neutralized by pre-treating their citrated plasma samples with DOAC-Remove. This strategy has the potential of saving costs by avoiding both repeated testing and misinterpreted LA results.
[Figure 1. Comparison of basic coagulation tests, lupus anticoagulant, anti-Xa and DOAC levels before and after the addition of DOAC-Remove.]
To cite this abstract in AMA style:
Velasco-Rodríguez D, Vidal Laso R, López Pérez M, Martín Herrero S, Jíménez Barral E, García-Raso A, de la Plaza R, López Romero LF, Mínguez D, Bueno MÁ, Llamas Sillero P. Doac-Remove Can Neutralize the Effect of Direct Oral Anticoagulants on Lupus Anticoagulant Assay: A Single-centre Experience [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/doac-remove%c2%99-can-neutralize-the-effect-of-direct-oral-anticoagulants-on-lupus-anticoagulant-assay-a-single-centre-experience/. Accessed October 1, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/doac-remove%c2%99-can-neutralize-the-effect-of-direct-oral-anticoagulants-on-lupus-anticoagulant-assay-a-single-centre-experience/