European Academy of Neurology 2026

New Insights into Epstein–Barr Virus Antibodies in Multiple Sclerosis

Posted on August 18, 2026  •  3 minutes  • 498 words

The link between the Epstein–Barr virus (EBV) and multiple sclerosis (MS) has become increasingly clear over the past decade. Today, EBV is widely considered a prerequisite for the development of MS, with elevated immune responses against the virus detectable many years before the first clinical symptoms appear. In particular, antibodies targeting the Epstein–Barr nuclear antigen 1 (EBNA1) have consistently been associated with an increased risk of developing the disease. However, while the quantity of these antibodies has been well studied, far less is known about how they function and whether they actively contribute to disease processes.

At the European Academy of Neurology (EAN) Congress 2026, BEHIND-MS researchers presented new findings that shed light on this important question. The study investigated the functional properties of EBNA1-specific antibodies in 60 people with MS and matched healthy controls from the Swiss MS Cohort.

Beyond measuring antibody levels, the researchers assessed how effectively these antibodies engage the immune system through Fcγ receptor binding and several antibody effector functions, including antibody-dependent cellular phagocytosis (ADCP), antibody-dependent complement deposition (ADCD), and antibody-dependent natural killer cell activation (ADNKA).

The results showed that people with MS not only had higher levels of EBNA1-specific antibodies, but that these antibodies also displayed enhanced Fc-mediated functional activity. This suggests that the antibodies are not simply markers of previous EBV infection but may play a more active role in shaping immune responses.

To better understand how these antibody functions relate to disease activity, the researchers also analysed paired blood samples collected from the same individuals during periods of active disease and remission. While EBNA1-specific antibody levels remained stable over time, Fcγ receptor binding and phagocytic activity increased significantly during active disease. Similar changes were observed for antibodies directed against EBV viral capsid antigen (EBV-CA), whereas no such changes were seen for influenza-specific antibodies. This finding points to a specific EBV-directed immune response that is closely linked to MS disease activity rather than a general increase in immune activation.

These findings suggest that EBNA1-specific antibodies in MS differ not only in quantity but also in their functional properties. The enhanced Fc-mediated activity observed during periods of disease activity raises the possibility that EBV-specific antibodies contribute to ongoing inflammation in MS.

By combining both humoral (antibody) and cellular immune profiling, researchers hope to gain a more complete understanding of how EBV influences the course of MS. Such insights could help identify new biomarkers of disease activity and open the door to future therapies targeting EBV-driven immune mechanisms.

Key Highlights - EBNA1-specific antibody alterations extend beyond antibody levels. People with MS show enhanced Fc-mediated functional properties in addition to increased antibody titers. - Disease activity is associated with stronger antibody function. Fcγ receptor binding and phagocytic activity increase during active disease, suggesting that pro-inflammatory EBV-specific antibody profiles track with MS activity. - EBV-specific antibody functions may contribute to MS pathology. The findings support the idea that Fc-mediated antibody functions play a role in disease mechanisms and represent a promising area for future therapeutic research.