Antibodies against Epstein-Barr virus don’t predict MS progression
Study: Their levels not associated with activity of neurodegenerative disorder
People with multiple sclerosis (MS) tend to have high levels of antibodies targeting the Epstein-Barr virus (EBV), but levels of these antibodies are not associated with disease activity or clinical worsening among MS patients.
That’s according to the study, “Evaluating the role of anti-EBV antibodies as biomarkers for the evolution of multiple sclerosis: A longitudinal study,” which was published in Multiple Sclerosis and Related Disorders.
“Our findings indicate a limited value for [antibodies targeting] EBV as a predictor of clinical or radiological disease progression in [people with] MS,” the researchers wrote.
Epstein-Barr virus causes infectious mononucleosis
MS is an inflammatory disorder that causes damage to the brain and spinal cord. The causes of MS aren’t fully understood, but a history of infection with EBV has been identified as a key risk factor.
EBV is best known as the virus that causes infectious mononucleosis, colloquially called “mono,” but it also often causes nonspecific childhood illnesses. The vast majority of adults have been infected with EBV at some point.
Although it’s not fully clear why EBV can set the stage for MS, one potential hypothesis is molecular mimicry. The basic idea is that certain EBV proteins have structures very similar to proteins that are normally found in healthy brain cells. When the immune system makes antibodies targeting the viral proteins, these antibodies may accidentally also target the body’s own healthy tissue, ultimately leading to MS.
In this study, a team of U.S. scientists hypothesized that measuring levels of anti-EBV antibodies might provide useful information about future disease activity in MS patients. To test this idea, the researchers tested for anti-EBV antibodies in 187 MS patients and 50 people without the disease, who served as controls.
These findings suggest that peripheral anti-EBV antibodies, while indicative of prior exposure [to the virus], have limited utility as a predictive biomarker for mid-term disease evolution in MS.
Consistent with prior research that has identified these antibodies as a potential cause of MS, the team found that MS patients had significantly higher average levels of antibodies targeting EBV than controls. More specifically, patients had higher levels of antibodies against the EBNA1 and VCA proteins in EBV.
Anti-EBV antibody levels also showed notable differences between people with relapsing and progressive forms of MS, with levels of anti-EBNA1 antibodies being significantly higher in relapsing MS and anti-VCA antibodies trending toward being significantly lower in these patients.
The researchers then conducted a battery of statistical tests looking for associations between anti-EBV antibody levels and clinical outcomes in the MS patients. Neither of the two antibodies assessed showed any correlation with measures of disability, including total Expanded Disability Status Scale scores, confirmed disability progression, and progression independent of relapse activity, over an average of more than five years of follow-up.
There were also no significant associations between antibody levels and MRI lesions, brain volume loss, damage to the optic nerve (which sends information from the eyes to the brain), and biomarkers of nerve damage. Treatment with disease-modifying therapies similarly had no effect on EBV antibody levels.
“These findings suggest that peripheral anti-EBV antibodies, while indicative of prior exposure [to the virus], have limited utility as a predictive biomarker for mid-term disease evolution in MS,” the scientists concluded.
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