HHV-6 and EBV reactivation in relapsing remitting multiple sclerosis: Disability, progression, and inflammation links

Area of Science:

• Immunology
• Virology
• Neuroscience

Background:

• Reactivation of human herpesvirus 6 (HHV-6) and Epstein-Barr virus (EBV) is frequently observed in patients with multiple sclerosis (MS).
• The specific immune responses and their contribution to MS pathogenesis remain incompletely understood.

Purpose of the Study:

• To investigate immunoglobulin (IgG, IgM, IgA) responses to specific viral antigens from HHV-6 and EBV in patients with relapsing-remitting MS (RRMS).
• To analyze immune profiles, including cytokines and chemokines, and their correlation with viral antibody responses and MS severity.

Main Methods:

• Enzyme-linked immunosorbent assays (ELISAs) were used to measure IgG, IgM, and IgA levels against EBV nuclear antigen EBNA, HHV-6, and EBV deoxyuridine-triphosphatase (dUTPase) peptides.
• Multiplex immunoassays were employed to quantify various cytokines, chemokines, and growth factors.
• Neural network analysis was utilized to assess predictive accuracy based on antibody responses and immune profiles.

Main Results:

• RRMS patients exhibited significantly higher IgG, IgA, and IgM responses to all tested viral antigens compared to healthy controls.
• IgG and IgM responses to HHV-6 dUTPase accurately distinguished RRMS patients (91.5% accuracy).
• Combining EBV-dUTPase antibodies with immune profiles achieved 97.1% predictive accuracy for RRMS.

Conclusions:

• HHV-6 and EBV reactivation significantly contribute to the pathogenesis of RRMS.
• Elevated antibody responses to viral dUTPases correlate with clinical disease severity (EDSS/MSS) and aberrant immune activation, including M1 macrophage and Th17 profiles.
• Cytokine-driven immune activation plays a crucial role in HHV-6 and EBV-associated MS.