Investigation of the relationship of herpes viruses with neuronal autoantibodies in multiple sclerosis and other demyelinating diseases

Little is known about the possible mechanism by which the autoimmune response leading to demyelination is triggered and its relationship to viruses. In this study, it is aimed to determine the relationship between Anti-EBV, Anti-HHV6A positivity levels and Anti-AQP4, Anti-flotillin, Neurofilament Light Chain (NfL) and Nogo-A levels in Multiple Sclerosis (MS) and Neuromyelitis Optica Spectrum Disorder (NMOSD) cases. Ethics Committee approval was obtained with the decision numbered 04.02.2020/74. CSF samples taken for diagnostic purposes of MS (n=19), NMOSD (n=8) and Pseudotumor Cerebri (PTS, n=15) cases aged 19-54 years who applied to our clinic were studied with ELISA and IFA methods (BAIBU BAP 2021.08.32.1503). Independent Sample T/Mann Whitney-U, Crosstabs-Fisher's Exact and Pearson/Spearman correlation analysis tests were used for group comparisons. A p value of <0.05 was considered statistically significant. The percentage of Anti-AQP4 positivity was highest in the PTS group, p=0.055. Nogo-A levels were higher in Anti-HHV6A positive MS (p=0.046) and PTS (p=0.015) cases. NfL levels were observed less in Anti-flotillin positive MS cases, p=0.051. Positive correlation between Nogo-A levels and Anti-HHV6A positivity in MS (p=0.046) and PTS (p=0.011) cases, disease onset age and NfL levels in NMOSD cases (p=0.027) and Nogo-A and NfL levels in PTS cases detected, p=0.031. According to the results obtained, it is recommended to evaluate Anti-AQP4 positivity in PTS cases at the diagnosis stage. It is thought that the high Anti-EBV positivity in three case groups may be a parameter to be used in treatment strategies rather than differential diagnosis. It is recommended that Anti-HHV6A is more effective in the differential diagnosis and that it should be studied with new biomarkers that show axonal damage in particular. There is a need for new multicenter studies with larger number of cases related to Anti-flotillin in the differential diagnosis.