NeuroVoices: Tanuja Chitnis, MD, on EBNA-1 Antibodies to Distinguish MS, MOGAD, and NMOSD

Differentiating multiple sclerosis (MS) from other neuroinflammatory disorders such as myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD) and neuromyelitis optica spectrum disorder (NMOSD) remains a persistent clinical challenge, particularly in seronegative cases where diagnostic clarity is limited. Although advances in imaging and antibody testing have improved diagnostic accuracy, overlapping features continue to complicate clinical decision-making.

Emerging research has increasingly focused on Epstein-Barr virus (EBV) as a key contributor to MS pathogenesis, with recent large-scale epidemiologic studies suggesting EBV infection is necessary, though not sufficient, for disease development. Building on this foundation, a recent multicenter, longitudinal case-control study evaluated whether persistent high-level titers of EBV-derived Epstein-Barr nuclear antigen 1 (EBNA-1) peptide antibodies could serve as a biomarker to distinguish MS from related neuroinflammatory diseases.

In the study, which included more than 2000 patients with neuroinflammatory disease and nearly 2000 healthy controls, persistent high EBNA-1 titers were observed in more than 95% of patients with MS across cohorts, compared with substantially lower rates in MOGAD and NMOSD. In a new iteration of NeuroVoices, Tanuja Chitnis, MD, Division Chief of Neuroimmunology at Brigham and Women’s Hospital and Professor of Neurology at Harvard Medical School, discusses the implications of these findings and the evolving role of EBV-related biomarkers in MS diagnosis.

NeurologyLive: Can you briefly outline the background of this study and why it was of interest?

Tanuja Chitnis, MD: Certainly. Epstein-Barr virus has been a very hot topic in multiple sclerosis research since the publication from Katie and Alberto Ascherio, demonstrating, using the Department of Defense cohort, that EBV is necessary for multiple sclerosis to occur. They showed this using EBV serologies, followed by neurofilament light (NfL) testing, and then MS diagnosis, with that sequence needing to occur.

I think now the community has really focused on EBV as a causative agent. Of course, it is not the only factor involved in MS pathogenesis, since almost 98% of the population will have EBV infection at some point and be seropositive. So we know it is necessary, but not sufficient, but it remains a very important area of focus.

The key question now is how EBV actually leads to MS and what the causative pathway is. The research presented here includes over 4000 samples selected from patients with multiple sclerosis, as well as other diagnoses including MOGAD, NMOSD, and healthy controls. Importantly, this included a large number of pediatric samples.

This is important because many adults will have evidence of EBV infection, but children are less likely to have EBV seropositivity at a younger age. We usually acquire EBV in childhood or adolescence, so studying younger patients provides an opportunity to observe differences between MS and other diseases earlier in the disease course. That was a large part of the rationale for including pediatric patients.

What were the key findings, and how does EBNA1 differ across MS and related disorders?

The results show that EBV antibodies, specifically EBNA1 antibodies, which are among the most commonly measured markers of EBV exposure, were positive in almost 98% to 99% of patients with MS. When compared with other diagnoses, including what some refer to as the “cousins” of MS, such as MOGAD and NMOSD, this becomes important.

This difference suggests that EBNA1 could serve as a differentiating factor and potentially a biomarker that helps distinguish MS from these related disorders. It is certainly not the only biomarker, as there are many others, including disease-specific antibodies in those conditions. However, in cases where it is difficult to distinguish between diagnoses or when certain tests are not available, this could provide an additional layer of information.

Looking more closely at the numbers, EBNA1 positivity in MS ranged from about 92% to 93% depending on the age group. In MOGAD, it was around 61%. In NMOSD, about 89%. In other neurological diseases, rates were in the 70% to 80% range, and in controls, about 78%.

So EBNA1 antibodies can be present in other conditions, but the prevalence is clearly highest in MS. Clinically, if I had a patient presenting with a neurological syndrome suggestive of MS or one of these related disorders and they were EBNA1 negative, that would give me pause and prompt me to think more carefully about the diagnosis.

That said, I do want to caution that there are rare cases of clearly defined MS where patients are EBNA1 negative. There may be reasons for this, such as low antibody titers or limitations of the assay being used. So while this is a helpful and suggestive marker, it is not definitive.

Where do you see EBNA1 fitting within the broader biomarker landscape in MS?

This EBNA1 antibody is certainly an important biomarker that is consistent with multiple sclerosis. If a patient is positive and also has the clinical features and MRI findings consistent with MS, then it adds confidence to the diagnosis. In that sense, it is complementary.

On the other hand, if a patient is negative, it does raise questions and may prompt further evaluation or consideration of alternative diagnoses. It becomes part of the broader diagnostic framework rather than something that stands alone.

There is also an evolving field of EBV-related antibodies in MS beyond EBNA1. This study focused on one antibody in depth, but there is ongoing work looking at other antibodies that may, in the future, be more specific and potentially more useful diagnostically.

As this research evolves, we may identify markers that better distinguish MS from other neuroinflammatory diseases and further refine how we approach diagnosis.

What are the next research steps in understanding EBV’s role in MS?

There is certainly a lot more work to be done on antibodies related to EBV and the broader serologic response to the virus. These are really markers of how the immune system responds to EBV, and it is possible that additional antibodies will emerge that are more specific and help us identify MS earlier or more accurately.

There is work that we are doing, as well as others in the field, focused on screening patients early for various EBV antibodies. This may help us better understand the timing of these immune responses and their relationship to disease development.

At the same time, there are still many fundamental questions that need to be answered. How does EBV actually lead to MS? Why does it occur in some individuals and not others? How does it interact with genetic susceptibility?

These are all areas of active investigation. We have ongoing work addressing some of these questions, and we hope to be publishing additional findings soon.

Hypothetically, could EBV-related markers eventually be incorporated into MS diagnostic criteria?

I think it is possible. However, we would need biomarkers or EBV-related factors that are highly specific for MS compared with related disorders such as MOGAD and NMOSD. EBNA1 may be one contributor, but it may ultimately require a panel of antibodies or a combination of factors to achieve the level of specificity needed for diagnostic use.

We are really looking for something that is highly specific and consistently present in MS, but not in other conditions. That would need to be validated in large, prospective cohorts. This study is an important step in that direction. It includes a large dataset and helps validate at least one antibody, but more work will be needed before something like this could be incorporated into formal diagnostic criteria.

REFERENCE
1. Vietzen H, Kuhner LM, Berger SM, et al. Epstein-Barr Virus Antibodies to Differentiate Multiple Sclerosis From Other Neuroinflammatory Diseases. JAMA Neurol. Published online March 9, 2026. doi:10.1001/jamaneurol.2026.0240