Multiple sclerosis: an autoimmune disease that attacks the myelin sheath and is associated with active nerve foci and the Epstein-Barr virus

Multiple sclerosis (MS) is the most common disabling neurological disease among young people and adults, affecting approximately 1 million people in the United States and 3.1 million people worldwide. The disease often appears between the ages of 20 and 40, and is more common in women than in men, according to the US National Institutes of Health.

Multiple sclerosis is an autoimmune disease, in which the immune system mistakenly attacks healthy body tissues. In the case of multiple sclerosis, this attack targets the myelin sheath that surrounds nerve fibers. Myelin consists of proteins and fats, and acts as an insulating layer that helps transmit nerve signals quickly and efficiently. According to the US National Institutes of Health, myelin damage hinders the transmission of signals between the brain and different parts of the body.

William Robinson of Stanford University explains the nature of the disease with a simple analogy: “Attacking the myelin sheath in multiple sclerosis is like stripping the insulation off an electrical wire, disrupting the transmission of signals.” As a result, nerve signals may become slower or have difficulty reaching their destination normally.”

Neurological foci may reveal the progression of the disease

Research led by a team from the US National Institutes of Health, led by Daniel Reich, has shown that the presence of more chronic active nerve foci is associated with increased physical and cognitive disability in people with multiple sclerosis. Of the 192 people studied, more than half had at least one active chronic foci.

The presence of four or more foci has also been associated with an increased risk of developing the progressive form of the disease and the appearance of motor and cognitive disabilities at an early age. These findings suggest that chronic inflammation within the brain may be one of the main factors responsible for persistent neurological damage and disease progression.

In a related context, a recent study published in Nature Medicine supported the hypothesis that the role of the Epstein-Barr virus is not limited to contributing to the onset of multiple sclerosis, but may also be a catalyst for relapses of the disease when it reactivates.

The researchers believe that these results may pave the way for developing treatments that target the virus or the B cells associated with it to reduce future relapses.