Increased EBNA1-specific antibody response in primary-progressive multiple sclerosis

Area of Science:

• Neuroimmunology
• Virology
• Multiple Sclerosis Research

Background:

• Viral infections' impact on multiple sclerosis (MS) susceptibility and progression is primarily studied in relapse-onset MS (RMS).
• Limited research exists on immune responses to common viruses in primary progressive MS (PPMS).
• Understanding these responses in PPMS is crucial for disease management and therapeutic strategies.

Purpose of the Study:

• To investigate immune responses to ubiquitous viruses in patients with PPMS.
• To compare viral antibody levels in PPMS patients with healthy controls.
• To explore potential correlations between antiviral immunity and disease progression in PPMS.

Main Methods:

• Antibody responses to Epstein-Barr virus (EBV) (EBNA1, VCA), human herpesvirus 6 (HHV-6), human cytomegalovirus (HCMV), and measles virus were measured.
• A cohort of 68 PPMS patients with an 8-year follow-up was compared to 66 age- and sex-matched healthy controls.
• Seroprevalence rates and specific antibody titers were analyzed.

Main Results:

• PPMS patients exhibited significantly increased humoral immune responses to the latent EBV-encoded nuclear antigen-1 (EBNA1) compared to controls.
• No significant differences were found in responses to lytic EBV capsid antigen (VCA) or other tested viral antigens (HHV-6, measles).
• Seroprevalence rates for human cytomegalovirus (HCMV) were notably higher in the PPMS cohort. Baseline antiviral immune responses did not correlate with disability progression.

Conclusions:

• Elevated immune responses targeting EBNA1 are selectively increased in PPMS, suggesting a role in both RMS and PPMS pathogenesis.
• Chronic HCMV infection is associated with progressive MS, warranting further investigation.
• These findings highlight specific viral-associated immune dysregulation in progressive MS.