부산대학교 도서관

Previous studies have described the association of onchocerciasis (caused by Onchocerca volvulus) with epilepsy, including nodding syndrome, although a clear etiological link is still missing. Cases are found in different African countries (Tanzania, South Sudan, Uganda, Democratic Republic of the Congo, Central African Republic and Cameroon). In our study we investigated immunological parameters (cytokine, chemokine, immunoglobulin levels) in individuals from the Mahenge area, Tanzania, presenting with either epilepsy or nodding syndrome with or without O. volvulus infection and compared them to O. volvulus negative individuals from the same endemic area lacking neurological disorders. Additionally, cell differentiation was performed using blood smears and systemic levels of neurodegeneration markers, leiomodin-1 and N-acetyltyramine-O, β-glucuronide (NATOG) were determined. Our findings revealed that cytokines, most chemokines and neurodegeneration markers were comparable between both groups presenting with epilepsy or nodding syndrome. However, we observed elevated eosinophil percentages within the O. volvulus positive epilepsy/nodding syndrome patients accompanied with increased eosinophilic cationic protein (ECP) and antigen-specific IgG levels in comparison to those without an O. volvulus infection. Furthermore, highest levels of NATOG were found in O. volvulus positive nodding syndrome patients. These findings highlight that the detection of distinct biomarkers might be useful for a differential diagnosis of epilepsy and nodding syndrome in O. volvulus endemic areas. Trial-registration:NCT03653975. Author summary: A lot of epidemiological studies suggest that an infection with the filarial nematode Onchocerca volvulus is a risk factor for a certain form of epilepsy which includes the nodding syndrome. The seizures occur suddenly in previously healthy children between the ages of 3 and 18 years and the disease is an important public health problem in onchocerciasis-endemic regions with inadequate or lacking onchocerciasis elimination programmes. So far, no exact pathophysiological mechanisms were detected that shed light on how the parasite can trigger the seizures, although many factors have been investigated. However, most studies lack an accurate determination of an active/chronic O. volvulus infection; rather, they rely on the presence of circulating antibodies, which is only evidence of previous exposure to the parasite (and therefore positive in most people living in endemic areas. Within our study, we included participants from the Mahenge area, Tanzania, who were displaying epilepsy/nodding syndrome in absence or presence of a PCR-determined O. volvulus infection. We could show that the group of O. volvulus infected patients displayed higher levels of eosinophils, antigen-specific immunoglobulin levels as well as increased levels of a worm-related metabolic product (NATOG), which might be used as a potential diagnostic biomarker of the disease in future studies. [ABSTRACT FROM AUTHOR]