Toward a ready-to-use blood collection tube preventing direct oral anticoagulant-interference with routine...

Direct oral anticoagulants (DOACs) interfere with many coagulation assays. While in vitro plasma treatment with activated charcoal can overcome such interference, it requires technical support and is unsuitable for high-throughput workflows.

To circumvent such limitations, we added activated charcoal directly to citrated blood collection tubes and assessed the impact of such an approach on coagulation assays.

DOAC-spiked and patient whole blood samples (with and without DOACs) were treated with activated charcoal. Outcomes were residual DOAC plasma levels, routine coagulation assays, and specialized hemostasis assays (antithrombin, protein C, protein S, lupus anticoagulant testing, and thrombin generation assay).

DOACs became undetectable in 118 of 122 samples from patients who received DOAC after 10 minutes of treatment with activated charcoal. DOAC interference with prothrombin time and activated partial thromboplastin time was resolved in almost all samples from patients who received DOAC; fibrinogen, factor V, and D-dimer levels remained unchanged. Whole blood contact with activated charcoal led to a slight prolongation in prothrombin time and activated partial thromboplastin time and a small decrease in fibrinogen level in blood samples from patients without anticoagulated therapies, yet these changes were not clinically relevant. Conversely, the level of endogenous coagulation inhibitors was significantly reduced, and the level of thrombin generation was significantly enhanced.

Adding activated charcoal to whole blood corrected DOAC interference with routine coagulation assays with minimal, if any, impact on the results in the absence of DOACs, thus supporting the development of citrated blood collection tubes preloaded with activated charcoal. Their use would accelerate the laboratory workflow and lead to reliable routine hemostasis assay results in all patients receiving DOACs.