Urinary N-acetyltyramine-O,β-glucuronide in Persons with OnchocerciasisAssociated Epilepsy.

We investigated urinary N-acetyltyramine-O,β-glucuronide (NATOG) levels as a biomarker for active 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 infection, and in infected persons with epilepsy (PWE). Urinary NATOG concentration was positively associated with microfilarial density ( < 0.001). The median urinary NATOG concentration was higher in PWE (3.67 µM) compared to men without epilepsy (1.74 µM), = 0.017; and was higher in persons with severe (7.62 µM) compared to mild epilepsy (2.16 µM); = 0.008. Non-epileptic participants with and without infection had similar NATOG levels (2.23 µM and 0.71 µM, = 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: 0.633-0.797). Using the previously proposed cut-off value of 13 µM to distinguish between an active infection and an uninfected state, the sensitivity was 15.9% and the specificity 95.9%. In conclusion, an 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.