Seroprevalence of Epstein-Barr virus in Tunisian patients with multiple sclerosis: Associations with clinical characteristics.

BACKGROUND: Epstein-Barr virus(EBV) is recognized as the principal environmental risk factor for Multiple Sclerosis(MS).Given the distinctive clinical characteristics of Tunisian MS patients, investigating the role of EBV may provide insights into disease heterogeneity and progression. OBJECTIVE: Evaluate EBV seroprevalence and its association with clinical characteristics in Tunisian patients with MS. METHODS: A prospective cross-sectional study was conducted in MS Tunisian patients at the MS center of the Neurology Department,Razi University Hospital.Patients were diagnosed according to the 2017-McDonald criteria.EBV serology was assessed by electrochemiluminescence immunoassay, and its associations with clinical characteristics were analyzed. RESULTS: A total of 188 MS patients and 42-healthy controls(HC) were included.The mean age at disease onset was 29.8 years.The mean Expanded Disability Status Scale score was 3.49,and the annualized relapse rate was 0.67.EBV serology was positive in 88% of MS patients,while 12% exhibited an atypical EBV profile,compared with 75% EBV seropositivity among HC.VCA-IgG intensity was significantly higher in patients experiencing a relapse at the time of sampling(p = 0.016) and in those with the relapsing-remitting MS phenotype (p = 0.027).Female patients with atypical EBV profiles exhibited lower EDSS scores than seropositive females(p = 0.038).Visual system impairment was more frequent among patients with atypical EBV profiles(40.9%vs. 22.3%,p = 0.048).Significant differences were also observed in cognitive performance, with seropositive patients demonstrating greater impairment across BICAMS,FAB,and Beck Depression Inventory assessments (p < 0.05). CONCLUSIONS: EBV serological markers were associated with disease activity,functional impairment, and cognitive dysfunction in Tunisian patients with MS supporting a potential role for EBV-related immune dysregulation in disease expression.Further molecular studies are needed to clarify their role in disease progression.