Novel Ex Vivo DOAC Removal Methods Reduce Interference in Lupus Anticoagulant Testing

Area of Science:

• Clinical Chemistry
• Hematology
• Diagnostic Laboratory Science

Background:

• Direct oral anticoagulants (DOACs) are widely used but interfere with laboratory coagulation tests.
• This interference can lead to inaccurate results, particularly in lupus anticoagulant (LAC) testing.
• Accurate LAC testing is crucial for diagnosing thrombotic disorders.

Purpose of the Study:

• To evaluate the efficacy of commercial DOAC removal methods (DOAC Filter® and DOAC-Stop™) in eliminating DOAC concentrations.
• To assess the impact of these removal methods on reducing false-positive results in LAC screening.
• To determine if DOAC removal can decrease the need for further confirmatory or mixing tests in LAC diagnostics.

Main Methods:

• Fifty patient samples with high DOAC concentrations (apixaban, dabigatran, edoxaban, rivaroxaban) were analyzed.
• DOACs were removed ex vivo using either DOAC Filter® (n=28) or DOAC-Stop™ (n=22).
• Commercial control and calibrator samples were also tested (n=13 for DOAC Filter®, n=14 for DOAC-Stop™).
• LAC screening was performed before and after DOAC removal.

Main Results:

• Both DOAC Filter® and DOAC-Stop™ effectively reduced DOAC concentrations to a median of 0 ng/mL.
• Prior to DOAC removal, 96% of patient samples and over 90% of control samples showed false-positive LAC results.
• After DOAC removal, LAC screening became negative in 61% of patient samples treated with DOAC Filter® and 45% with DOAC-Stop™.
• All control samples tested negative for LAC after DOAC removal.

Conclusions:

• Ex vivo DOAC removal significantly reduces false-positive results in lupus anticoagulant screening.
• DOAC removal methods effectively eliminate drug interference, improving the reliability of LAC testing.
• These methods can halve the requirement for additional confirmatory tests, streamlining patient management and reducing healthcare costs.