Multiple Sclerosis Centers of Excellence
Epstein Barr Virus and Multiple Sclerosis
Mitch Wallin, MD, MPH, FAAN
MS is the most common inflammatory neurological disease of young adults. Around a million people in the US have MS. Despite years of study by researchers, the cause of MS remains unclear. One possibility is that an infection causes MS, or affects a person’s risk for MS. There have been two major theories surrounding this belief. The first theory is that MS is a rare complication of a common infection. This would be supported by finding that MS is more common in areas where certain infections are more common. Alternatively, the second theory is that MS is caused by a common infection occurring at a later than usual age in life.
In early 2022, researchers published a series of interesting studies providing more support for infection with Epstein-Barr virus (EBV) being associated with the onset of MS. EBV is a common infection that affects over 90% of people all over the world and most people are infected with EBV before age 25. EBV, a member of the herpes virus family, is spread mainly through saliva. When a person is infected with EBV they often have no symptoms. Some people with EBV develop mononucleosis, sometimes referred to as “mono” or the “kissing disease”, typically with a fever, fatigue, and a sore throat. After someone is infected with EBV the virus stays in their cells, specifically their B-lymphocytes, a type of immune cell, for the rest of their life.
To examine if EBV is associated with MS, researchers carried out various studies using blood serum samples from 955 military Veterans with MS. These Veterans had blood samples collected over time, both before and after they developed MS. These blood samples were stored in the Department of Defense serum repository. The researchers found that MS risk was 32 times higher in 801 of these Veterans after they became infected with EBV. There was no increased risk of MS after infection with other viruses that are spread similarly to EBV. They also found, looking at serum samples from 25 Veterans with MS who acquired EBV during the study, that levels of neurofilament light chain, a substance that rises in the blood when there is degeneration of nerves, increased after these Veterans had evidence of EBV infection in the blood. Finally, they found that EBV antibody levels were higher in the serum from 30 Veterans with MS compared to the serum from 30 Veterans without MS.
These studies, as well as earlier studies on EBV and MS, support that, at least in some people, EBV is associated with onset of MS, particularly if infection occurs later in life than usual. Further studies in other groups are needed to confirm an association between EBV and MS and, if this association is confirmed, to figure out how EBV might trigger MS. If EBV is found to increase the risk for MS, it is possible that the risk for EBV infection could be reduced by EBV vaccines currently in development.
These studies are important because by better understanding potential causes of MS we may one day be able to prevent MS. This MS research was made possible by the availability of serum from members of military.
