Scientists can understand the link between the common virus and MS

by Dennis Thompson

HealthDay Reporter

THURSDAY, May 18, 2023 (HealthDay News) — It’s been known for years that the Epstein-Barr virus can trigger multiple sclerosis or drive the progression of the degenerative disease, and Swedish researchers think they now understand why.

Some people have antibodies to the common Epstein-Barr virus that mistakenly attack a protein found in the brain and spinal cord, say researchers at the Karolinska Institutet in Sweden.

Antibodies that bind to a specific protein on the virus, EBNA1, are also capable of binding to a similar protein in the brain and spinal cord called CRYAB, the researchers found by analyzing blood samples from more than 700 MS patients. .

These misdirected antibodies can damage the nervous system and cause severe symptoms in MS patients, including problems with balance, mobility and fatigue, the researchers believe.

“MS is an incredibly complex disease, but our study provides an important piece of the puzzle and could explain why some people develop the disease,” said co-lead author Olivia Thomas, a postdoctoral researcher in the Department of Clinical Neuroscience.

“We found that certain Epstein-Barr virus antibodies, which would normally fight infection, can mistakenly target the brain and spinal cord and cause damage,” he said in an institute news release.

The antibodies were present in about 23 percent of the MS patients compared with just 7 percent of a group of 700 healthy people, the study found.

“This shows that while these antibody responses are not required for disease development, they may be involved in the disease in up to a quarter of MS patients,” Thomas said.

Epstein-Barr, a herpesvirus, is one of the most widespread viruses in humans. More than 90% of the world’s population is infected and carries the virus for life, usually as a latent infection with no symptoms, the researchers said in background notes.

Mounting scientific evidence has suggested that infection precedes MS and that antibodies to the virus may be involved. However, the mechanism by which this occurs appears to vary between patients and remains largely unknown.

The researchers also found that there is likely a similar cross-reactivity between the T cells of the immune system, which could offer another pathway through which having Epstein-Barr can lead to MS.

“We are now expanding our research to investigate how T cells fight EBV infection and how these immune cells can damage the nervous system in multiple sclerosis and contribute to disease progression,” said co-senior author Mattias, MD. Bronge, a research affiliate at the institute. Department of Clinical Neuroscience, he said in the statement.

The new study was published May 17 in the journal Progress of science.

More information

The Harvard TH Chan School of Public Health has more about the Epstein-Barr virus and multiple sclerosis.

SOURCE: Karolinska Institutet, press release, May 17, 2023