Urinary N-acetyltyramine-O,β-glucuronide in Persons with Onchocerciasis<i>-</i>Associated Epilepsy

• Main Authors: An Hotterbeekx, Alfred Dusabimana, Michel Mandro, Germain M Abhafule, Wonya’Rossy Deogratias, Joseph N. Siewe Fodjo, Steven Abrams, Robert Colebunders
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Pathogens
• Subjects: <i>onchocerca volvulus</i>; n-acetyltyramine-o,β-glucuronide (natog), epilepsy; africa; biomarker; urine
• Online Access: https://www.mdpi.com/2076-0817/9/3/191

We investigated urinary N-acetyltyramine-O,&#946;-glucuronide (NATOG) levels as a biomarker for active <i>Onchocerca volvulus</i> infection in an onchocerciasis-endemic area in the Democratic Republic of Congo with a high epilepsy prevalence. Urinary NATOG was measured in non-epileptic men with and without <i>O. volvulus</i> infection, and in <i>O. volvulus-</i>infected<i> </i>persons with epilepsy (PWE). Urinary NATOG concentration was positively associated with microfilarial density (<i>p </i>&lt; 0.001). The median urinary NATOG concentration was higher in PWE (3.67 &#181;M) compared to men without epilepsy (1.74 &#181;M), <i>p </i>= 0.017; and was higher in persons with severe (7.62 &#181;M) compared to mild epilepsy (2.16 &#181;M); <i>p </i>= 0.008. Non-epileptic participants with and without <i>O. volvulus </i>infection had similar NATOG levels (2.23 &#181;M and 0.71 &#181;M, <i>p</i> = 0.426). In a receiver operating characteristic curve analysis to investigate the diagnostic value of urinary NATOG, the area under the curve was 0.721 (95% CI: 0.633&#8722;0.797). Using the previously proposed cut-off value of 13 &#181;M to distinguish between an active <i>O. volvulus </i>infection and an uninfected state, the sensitivity was 15.9% and the specificity 95.9%. In conclusion, an <i>O. volvulus</i> infection is associated with an increased urinary NATOG concentration, which correlates with the individual parasitic load. However, the NATOG concentration has a low discriminating power to differentiate between infected and uninfected individuals.