Researchers have found further evidence for how the Epstein-Barr virus can trigger multiple sclerosis or drive disease progression. A new study shows that some individuals have antibodies against the virus that mistakenly attack a protein in the brain and spinal cord.

The Epstein-Barr virus infects most people early in life and then remains in the body, usually without causing symptoms. The link between EBV and the neurological disease MS was discovered many years ago and has puzzled researchers ever since. Increasing evidence suggests that EBV infection precedes MS and antibodies against the virus may be involved. However, the molecular mechanisms seem to vary between patients and remain largely unknown.

Researchers at Karolinska Institutet, in Sweden, analyzed blood samples from more than 700 patients with MS and 700 healthy individuals. They found that antibodies that bind to a certain protein in the Epstein-Barr virus, EBNA1, can also bind to a similar protein in the brain and spinal cord called CRYAB, whose role is to prevent protein aggregation during conditions of cellular stress such as inflammation. These misdirected, cross-reactive antibodies may damage the nervous system and cause severe symptoms in MS patients, including problems with balance, mobility, and fatigue. The antibodies were present in about 23 percent of MS patients and 7 percent of control individuals.

The researchers also found that there is likely a similar cross-reactivity among T cells of the immune system.

The findings were published in Science Advances.