Cytomegalovirus Seropositivity and Its Impact on Clinical Progression of Multiple Sclerosis: A Case-Control Study from Northeastern Iran

significantly lower serum anti-CMV IgG levels compared to healthy individuals (178.7 ± 61.92 vs. 342.9 ± 3.121, p < .0001). Ethnicity and EDSS scores influenced anti-CMV IgG levels, with higher EDSS scores correlated with lower serum levels. In patients with relapsing-remitting multiple sclerosis (RRMS), serum levels of anti-CMV IgG exhibited significant variations based on age, EDSS scores, and the disease duration. Conclusion: This study reveals a complex link between CMV infection and MS. While anti-CMV IgG antibodies were found in both MS patients and healthy individuals, lower levels in MS patients might suggest a protective effect against MS progression. Additionally, reduced anti-CMV IgG levels correlated with higher EDSS scores, indicating that diminished CMV-specific immunity could worsen disease severity, especially in RRMS patients.