Common Viral Antibodies Could Trigger MS, Research Reveals | Multiple sclerosis

Scientists have uncovered how a common childhood virus can trigger multiple sclerosis (MS), in findings that could pave the way for new treatments for this devastating disease.

Research suggests that the body’s immune response to Epstein-Barr virus (EBV), a normally harmless infection, may misfire and mistakenly target a crucial protein in the brain and spinal cord.

“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 Dr Olivia Thomas, from Sweden’s Karolinska Institute and co-lead author of the article.

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

This discovery could help in the development of treatments to protect the central nervous system from damage caused by the immune system. Current therapies are effective in reducing MS relapses, but none can prevent disease progression.

The advance follows a 20 year historical study of 10 million US military released last year, which provided compelling evidence that Epstein-Barr can trigger MS. It showed that people infected with EBV are 32 times more likely to develop the incurable disease.

“We know that’s almost a prerequisite for developing MS — you can’t really get MS without first getting EBV,” Thomas said. “Epidemiologically, we’re pretty confident that EBV is one of the main contributors, but we still don’t know what the mechanism is.”

EBV is one of the most common viruses in humans. Over 90% of the world’s population is infected, and most people have only mild cold symptoms. After infection, the virus remains dormant in the body, kept suppressed by antibodies.

However, the latest work suggests that, in some people, these antibodies may be involved in triggering MS.

They found that antibodies that bind to a certain Epstein-Barr virus protein, EBNA1, can also bind to a very similar-looking protein in the brain and spinal cord called CRYAB, which plays a crucial role in protecting against the effects of inflammation. .

If antibodies mop up CRYAB, it could damage the nervous system and contribute to serious symptoms in MS patients, including problems with balance, mobility and fatigue.

The researchers analyzed blood samples from more than 700 MS patients and 700 healthy people and found that cross-reacting antibodies were present in about 23% of MS patients and 7% of control individuals.

“This shows that although these antibody responses are not necessary for disease development, they may be involved in disease in up to a quarter of MS patients,” Thomas said. “It also demonstrates the wide variation between patients, highlighting the need for personalized therapies.”

Scientists believe that T cells, which work in parallel with antibodies, could target the same EBV protein, meaning they are also likely to be involved in generating an autoimmune response. This could at least partly explain how the virus triggers MS in patients who test negative for antibodies.

It’s also unclear why some healthy people carry the antibodies with no apparent ill effects. One possibility is that, in these people, the antibodies were only present in the blood, but in the MS patients, they had crossed the blood-brain barrier.

The results are published in the journal Scientists progress.