Common viral antibodies ‘could trigger MS’

Common viral antibodies could trigger the onset of Multiple Sclerosis (MS), new research has revealed, as the body fights off the Epstein-Barr virus. 

The Epstein-Barr virus (EBV) infects most people early in life and then remains in the body, usually without causing symptoms. 

The link between EBV and MS was discovered many years ago and has puzzled researchers ever since, with new research last year suggesting that EBV infection precedes MS and antibodies against the virus may be involved. 

However, in new research from Karolinska Institutet, it is shown that some individuals have antibodies against the virus that mistakenly attack a protein in the brain and spinal cord.

“MS is an incredibly complex disease, but our study provides an important piece in the puzzle and could explain why some people develop the disease,” says Olivia Thomas, postdoctoral researcher at the Department of Clinical Neuroscience, Karolinska Institutet and shared first author of the paper. 

“We have discovered that certain antibodies against the Epstein-Barr virus, which would normally fight the infection, can mistakenly target the brain and spinal cord and cause damage.”

The researchers analysed 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 per cent of MS patients and seven per cent of control individuals.

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

“This also demonstrates the high variation between patients, highlighting the need for personalised therapies. Current therapies are effective at reducing relapses in MS but unfortunately, none can prevent disease progression.”

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

“We are now expanding our research to investigate how T cells fight EBV infection and how these immune cells may damage the nervous system in multiple sclerosis and contribute to disease progression,” says Mattias Bronge, affiliated researcher at the Department of Clinical Neuroscience, Karolinska Institutet and shared first author of the paper.