- New research has uncovered why the Epstein-Barr virus (EPV) may contribute to multiple sclerosis (MS).
- Certain antibodies that the body produces to fight the infection may mistakenly go after the brain and spinal cord, damaging the nervous system.
- This may contribute to balance and mobility problems associated with MS.
- However, because a majority of people get EPV early in life while only a small percentage develop MS, experts say other mechanisms like genetic risk factors may also be at play.
According to the findings, published in Science Advances Wednesday, certain antibodies the body produces to fight the infection may mistakenly go after the brain and spinal cord, damaging the nervous system and contributing to balance and mobility problems associated with MS.
In addition, T cells, another part of the immune response that provides protection against infections, may also misfire and attack the nervous system.
Prior evidence suggests that EBV infection is a prerequisite for MS, and scientists are just starting to uncover the mechanisms in which the virus may contribute to the development of the chronic inflammatory autoimmune disease of the central nervous system.
Over 90% of the population has had an EBV infection but only a small percentage develop MS, suggesting that other mechanisms — like genetic risk factors — are at play.
“This new paper supports many other studies that point to molecular mimicry as a major way that EBV infection contributes to the development of MS. Molecular mimicry is the idea that when the immune system targets EBV, it sometimes also ends up targeting human proteins that look like EBV proteins,” Dr. Michael Sy, an assistant professor with the Comprehensive Multiple Sclerosis Center at University of California, Irvine’s School of Medicine, told Healthline.
To better understand how EBV may trigger MS is certain people, researchers at Karolinska Institutet in Sweden examined the blood samples of 713 people with MS and 722 healthy individuals.
They found that the antibodies the body produces to fight the infection, known as EBNA1, can also bind to a protein, called CRYAB, located in the brain spinal cord that protects the body from the harmful effects of inflammation.
When EBNA1 antibodies bind to the CRYAB proteins, as the study suggests, they could damage the nervous system, leading to MS problems relating to balance, mobility, and fatigue.
The misdirected antibodies were detected in about 23% of people with MS and 7% of those who were healthy.
“In MS, the immune system is targeting molecules in the myelin sheath of the brain that look similar to molecules in EBV leading to damage to one’s own brain and spinal cord,” said Sy.
There also appeared to be cross-reactivity among T cells, which the body also stimulates to produce antibodies that fight infections.
“It seems highly likely that these misdirected cross-reactive B cells, antibodies, and T cells influence neuroinflammation and contribute to the disease,” Dr. Tobias Lanz, an assistant professor of immunology and rheumatology at Stanford Medicine who has been trained in neurology, says.
Most people, about 90%, are infected with EBV early in life.
The virus stays in the body, dormant, typically without causing symptoms.
For years, scientists have known there’s a link between EBV and MS, with prior research suggesting the risk of MS increases 32-fold after an EBV infection.
A large study from 2022 found that nearly 100% of people with MS had previously been infected with EBV.
“Studies indicate that Epstein-Barr virus infection is necessary to develop MS. It appears to be almost impossible to get MS if you haven’t first been infected with EBV,” says Sy.
Not everyone who gets infected with EBV develops MS, and some otherwise healthy individuals may have these antibodies and never develop MS.
“Other genetic and environmental risk factors likely add additional risk to develop the disease,” says Lanz.
The variability in immune responses, and how they affect the nervous system, indicate that MS prevention needs to be highly personalized, according to the researchers.
Eradication or suppression of EBV may also help prevent future cases of MS, says Sy.
And, according to Lanz, these findings may help scientists develop a vaccine against EBV that will help prevent MS.
“Currently, there is no EBV-specific therapy in MS. But understanding the exact mechanisms will likely reveal EBV molecules that could be targeted directly,” Lanz said.
New research has uncovered why the Epstein-Barr virus may contribute to multiple sclerosis.
Certain antibodies that the body produces to fight the infection may mistakenly go after the brain and spinal cord, damaging the nervous system and contributing to balance and mobility problems associated with MS, the report suggests.