PB0145 - Influence of DOACs on measurements of lupus anticoagulants

Sunday, June 23, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

Konomi Igarashi

Clinical Laboratory Technologist
Keio University Hospital
Nakano-Ku, Tokyo, Japan

Co-Author(s)

MW

Masatoshi Wakui

Associate Professor
Keio University
Shinjuku-ku, Tokyo, Japan
SO

Shusaku Oka

Clinical Laboratory Technologist
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
YF

Yuta Fujimori

Clinical Laboratory Technologist
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
EO

Emiri Osada

Clinical Laboratory Technologist
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
SN

Shoko Nakamura

Clinical Laboratory Technologist
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
YO

Yuko Ozaki

Clinical Laboratory Technologist
Keio Univesity Hospital
Shinjuku-ku, Tokyo, Japan
TN

Terumichi Nakagawa

Clinical Laboratory Technologist
Keio Univerisy Hospital
Shinjuku-ku, Tokyo, Japan
MA

Mika Araki

Clinical Laboratory Technologist
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
YY

Yoko Yatabe

Clinical Laboratory Technologist
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
TA

Tomoko Arai

Clinical Laboratory Technologist
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
HY

Hiromitsu Yokota

Manager
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
HM

Hiromichi Matsushita

Professor
Keio University
Shinjuku-ku, Tokyo, Japan

Background: Direct oral anticoagulants (DOACs) may affect lupus anticoagulant (LA) measurements.

Aims: We investigated the influence of DOACs on LA measurements to detect thrombotic predisposition by comparing test results from two reagents for diluted Russell's viper venom time (dRVVT) method and one reagent for silica clotting time (SCT) method.

Methods: The samples were prepared by adding DOACs (Dab, dabigatran; Api, apixaban; Edo, edoxaban; and Riv, rivaroxaban) at various concentrations to normal plasma. We measured LA by using LA reagent DRVVT (Sysmex Co., S-DRVVT). LA measurements for these samples by using Hemosil dRVVT (IL Japan Co., H-dRVVT) and Hemosil STC (IL Japan Co., H-STC) were outsourced.

Results: In S-DRVVT, the addition of Riv caused an increase in LAR to exceed the cutoff value, resulting in the false positivity. DOACs other than Riv exhibited an increase in LAR depending on the concentrations without exceeding the cutoff value. H-dRVVT showed LA false positivity caused by Riv, similarly to S-DRVVT. For DOACs other than Riv, LA1 and LA2 in H-dRVVT were prolonged, depending on the concentrations of DOACs. LAR was slightly increased by adding Dab without exceeding the cutoff value, while Api and Edo tended to decrease LAR. H-STC showed prolongation of the screen time and the confirm time with the STC ratio tending to decline, which was caused by DOACs.

Conclusion(s): In the dRVVT methods, the LA false positivity occurred due to adding Riv. The influence of other DOACs varied by the reagent used for the dRVVT method. In the STC method, the STC ratio tended to decline by adding each DOAC. Since DOACs affect LA measurements, it would be needed to ascertain whether patients are on anticoagulation with DOACs and how the assay reagents exhibit such affection. For further assessment, experimental studies by using LA-positive plasma spiked with DOACs are underway.