About three million people worldwide have the multiple sclerosis (MS) disease known as multiple sclerosis. Scientists think they have uncovered a cause of this incurable disease. This is a virus that almost anyone can catch. So what does this finding mean for MS treatment and even disease prevention?
The brain is like an orchestra of electrical activity. Billions of nerve cells called neurons produce certain electrical signals. When these come together, the resulting symphony determines who we are, our thoughts, our emotions, our control over our bodies, and how we experience the world around us.
But there is a saboteur in multiple sclerosis. Our own immune system starts to work against the neurons and there is no longer a concerted orchestra and this has a devastating effect.
What misleads the immune system is a long-debated topic. But research published this year points to the Epstein-Barr virus.
“There is very strong evidence that MS is probably caused by this virus,” says Professor Gavin Giovannoni of Queen Mary University of London.The Epstein-Barr virus (EBV) is so common that almost all of us have a chance of contracting it in our lifetime. Most of us don’t even realize it, but this virus is notorious for the “kiss disease”, also known as glandular fever or mononucleosis.
EBV is transmitted primarily from person to person through close contact with mouth and throat fluids and bodily secretions. It is also called the kissing disease because it is most commonly transmitted through saliva. EBV has been on the list of MS suspects for decades, but conclusive evidence has been difficult to find because the virus is so common and multiple sclerosis is so rare.
The most important piece of evidence came from the US military, which takes blood samples from soldiers every two years. These blood samples, kept in the Department of Defense Serum Storage freezers, are seen as an important resource for research.
“The risk increases more than 30 times”
A team at Harvard University analyzed samples from 10 million people to establish the link between EBV and multiple sclerosis.
The team found 955 people diagnosed with multiple sclerosis and studied the course of the disease by looking at regular blood samples. The results of the research were published in the journal Science.
Harvard’s Prof. “Individuals who are not infected with the Epstein-Barr virus almost never get multiple sclerosis,” said Alberto Ascherio:
“The risk of multiple sclerosis increases more than 30 times after infection with the Epstein-Barr virus.”
The team also checked for other infections, such as cytomegalovirus (human herpes virus), but only the Epstein-Barr virus had a clear link to MS.
After the soldiers were infected with the EBV virus, waste was detected in the blood, indicating signs of brain injury. About five years after infection, he was diagnosed with MS.
prof. Ascherio says the study is the “first” convincing evidence that EBV causes disease. He notes that viruses can infect many people, but only cause serious complications in some. For example, before there were vaccines to prevent childhood diseases, “almost all children” contracted the polio virus, while one in 400 children suffered a stroke.
How can you be sure?
To conclusively prove that the virus plays a critical role in the disease, a study that could prevent people from contracting EBV and see if it prevents MS will be needed.
There are also studies trying to understand what the virus causes in the body.
If we focus on a single neuron (nerve cell), that is, a single instrument in the brain orchestra, this cell is covered with a fatty layer called myelin sheath. It is this layer of fat that allows neurons to fire electrical signals at 100 meters per second. But in multiple sclerosis, the immune system attacks the myelin, disrupting the electrical signals and eventually damaging the neuron.
Depending on which part of the brain or spinal cord is affected, multiple sclerosis can cause numbness, blurred vision, difficulty walking, slurred speech, and some people may find their memory or emotions affected.
