Study Finds MS Patients Have Stronger T-Cell Response to Replicating Epstein-Barr Virus Than Those Without MS

Researchers found that people with multiple sclerosis produced twice as many CD4 T-cells targeting proteins from actively replicating Epstein-Barr virus compared with people without the condition. The study, published in Science Translational Medicine, examined immune responses in 60 participants total.

New Scientist reported that in the 30 people with MS, most of those T-cells focused on viral proteins made during replication rather than dormant-stage proteins.

Low levels of the virus appeared in saliva samples from MS patients before treatment, confirming active replication. The same researchers tracked T-cell activity in 60 people with MS before and after B-cell reducing drug treatments. Those treatments lowered the T-cell response to Epstein-Barr virus to levels seen in people without MS, and viral levels in saliva fell below detection in most cases.

Michael Levy at Harvard Medical School said there are no good Epstein-Barr virus drugs currently available but they can be developed. Kjetil Bjornevik at the Harvard T.H. Chan School of Public Health said most MS researchers agree the virus plays a major role in the disease.

Natalia Drosu at Massachusetts General Hospital said the study examined which parts of the virus the immune system responds to in people with MS versus those without. Nearly everyone is infected with Epstein-Barr virus in childhood or teenage years, yet only about one in 1,000 people develop MS. B-cell depleting drugs already used for MS reduce harmful immune responses.

The results indicate these drugs also work by removing B-cells that harbor replicating virus, according to the researchers.