Evaluation of DOAC Dipstick Test for Detecting Direct Oral Anticoagulants in Urine Compared with a Clinically Relevant Plasma Threshold Concentration

Abstract

Measuring direct oral anticoagulant (DOAC) concentrations might be necessary in certain clinical situations but is not routinely performed. The DOAC Dipstick is a new rapid test for detecting DOACs in urine. The aim of this study was to evaluate the possible uses and limitations of the DOAC Dipstick and to compare visual analysis and DOASENSE Reader analysis of DOAC Dipstick pads. Plasma and urine samples were collected from 23 patients taking DOACs. DOAC concentrations in plasma and urine were measured by chromogenic substrate assays and in urine also by the DOAC Dipstick. Plasma concentrations were dichotomized at a threshold of ≥30 ng/mL. Patient samples were compared with samples from control individuals not using anticoagulants (n = 10) and with DOASENSE control urines. The Combur-10 test was used to measure parameters that may affect urine color and hence the interpretation of the DOAC Dipstick result. DOAC Dipstick test results were positive in 21/23 patient urine samples at a plasma DOAC concentration of ≥30 ng/mL and in 2/23 patient urine samples at a plasma DOAC concentration of <30 ng/mL. Inter-observer agreement was above 90% for visual analysis of patient urine samples and was 100% for DOASENSE Reader analysis of patient urines and for analysis of control group urines and DOASENSE control urines. Abnormalities in urine color detected by the Combur-10 test did not affect the DOAC Dipstick results. DOAC Dipstick detects DOACs in urine at a plasma threshold of ≥30 ng/mL. Positive DOAC Dipstick results should be confirmed by measuring DOAC plasma concentration.

Grundlagen zur Anwendung von Andexanet

“…Auch aus Urin kann mittlerweile eine Bestimmung der Konzentration der DOAK erfolgen. 33,34 Das Prinzip ist eine Messung über Farbindikatoren, nachdem der Chromophor eines Faktor-Xa-spezifischen Peptids durch den Faktor Xa der Probe freigesetzt wird. Letztendlich ist die Bestimmung des DOAK zwar möglich; eine Korrelation zur Blutkonzentration konnte aber bisher nur eingeschränkt gezeigt werden.…”

Direct oral anticoagulants (DOACs): From the laboratory point of view

“…Regarding measuring DOAC concentrations in urine, it is important to point out that the measurement is much quicker than in plasma samples and it takes approximately 10 minutes to obtain a result with the DOAC Dipstick. However, because the DOAC Dipstick result is interpreted visually, it is observer-dependent and may be invalid if the urine colour is abnormal (74). These potential errors can be eliminated by using the reader ( DOASENSE GmbH, Germany).…”

Can We Improve on the Rapid Assessment of Clinically Relevant Levels of Direct Acting Oral Anticoagulants (DOAC)?

“…12,13 Two recently published papers in Clinical and Applied Thrombosis/Hemostasis provide further detail to support the clinical utility of the DOAC Dipstick test. 14,15 The publication by Örd, et al 14 confirms that the DOAC urine Dipstick test detects DOACs at the clinically relevant plasma level of ≥30 ng/mL, the threshold determined in clinical trials 6,16 during development of the DOACs. The second paper by Harenberg, et al clarified that heparin and low-molecular-weight heparin will not interfere in the DOAC Dipstick test.…”

“…15 Both of the published papers in this journal provide data validating the functionality and analytical performance, demonstrate inter-operator agreement, and lack of color interferences in the dipstick reading. 14,15 DOACs have become a mainstay option for anticoagulant management. The challenges that the clinical community has faced with the laboratory assessment of DOACs may now be improving with the development of new test systems.…”

“…15 Both of the published papers in this journal provide data validating the functionality and analytical performance, demonstrate inter-operator agreement, and lack of color interferences in the dipstick reading. 14,15…”