Viral seropositivity in a Brazilian cohort of patients with multiple sclerosis: A retrospective descriptive study.

BACKGROUND: Defining viral serology in multiple sclerosis (MS) patients has become increasingly more relevant, given the potential association between viruses and MS, along with the recent introduction of new immunosuppressive treatments. OBJECTIVES: To describe the frequency of viral seropositivity in a Brazilian cohort of patients with MS and to explore the association of disease-modifying therapies (DMTs) and intravenous pulse therapy (IVPT) with viral serological status. METHODS: This retrospective descriptive study evaluated the seropositivity of ten viral markers in 70 patients with MS followed by a specialist at a neurological center in Brazil. Serological testing was performed according to routine clinical practice; therefore, not all patients were tested for every viral marker. RESULTS: High frequence of IgG seropositivity was observed for Epstein-Barr virus (95.1%), rubella (95.7%), varicella-zoster virus (87.5%), and cytomegalovirus (87.2%). Anti-HBs positivity was detected in 45.2% of patients, whereas no cases of HBsAg, HIV, HCV, or HTLV-I/II were identified. IgM positivity was uncommon. No statistically significant differences in viral seropositivity were detected according to DMT or recent IVPT exposure. CONCLUSIONS: This study describes the viral serological profile of a Brazilian cohort of patients with MS and supports the clinical value of baseline viral screening for vaccination planning and treatment evaluation. The analyses according to DMT and a recent IVPT exposure should be considered exploratory, and prospective studies with standardized viral screening are needed to better define the impact of these therapies on viral serological status.