Evaluation of DOAC Filter, a new device to remove direct oral anticoagulants from plasma samples.

Introduction: Directs oral anticoagulants (DOACs) can interfere with coagulation assays, especially in thrombophilia workup. To avoid these interferences, a new device, DOAC Filter, allows the removal of DOACs from citrated plasma. This study aims to confirm that DOAC Filter efficiently removes DOACs and to ascertain that coagulation assays are not impacted by filtration.

Methods: Directs oral anticoagulants Filter (Diagnostica Stago, France) is a filtration cartridge in which DOAC molecules are trapped by noncovalent binding, while plasma is filtered through a solid phase. Normal pool plasma (NPP) spiked with DOACs up to 300 ng/mL, with dabigatran etexilate (n = 27), rivaroxaban (n = 35), apixaban (n = 33), and edoxaban (n = 27) or 120 ng/mL for betrixaban (n = 4), and 18 plasma's samples from DOAC-treated patients were used to assess efficacy. The potential impact of DOAC Filter on coagulation assays was evaluated with NPP and plasma's samples from positive and negative lupus anticoagulant (LA) patients.

Results: Directs oral anticoagulants concentrations measured after filtration were below the limit of detection (LoD) of DOAC-specific assays for all plasmas tested, except for one apixaban plasma sample, with postfiltration concentration slightly higher than anti-Xa assay LoD (25.1 ng/mL). Coagulation assays results varied between -4 and +8% after filtration and between -6 and +8% for LA plasmas. Such limited variations are not expected to have any clinical impact.

Conclusion: Directs oral anticoagulants Filter efficiently removes DOACs from plasma and achieves concentrations below DOAC-specific assays LoD, except in the case of one apixaban sample. The integrity of plasma is respected, and the cartridge seems not to impact LA diagnosis.