In the past, many researchers have hypothesized a link between multiple sclerosis (MS) and different viruses or viral infections. While these hypotheses are varied in nature, there has rarely been a chance to establish a concrete relationship between the two – until now. According to Medical XPress, a research team from Stanford Medicine has now concretely connected Epstein-Barr virus (EBV) with multiple sclerosis development. In particular, the research showed how EBV creates the EBNA1 protein and mimics GlialCAM, a protein created in our own brain and spinal cord. So when the immune system tries to clear the virus from the body, it also attacks the GlialCAM protein, damages the myelin sheath, and causes MS symptoms.
To read the full study findings, take a look at the article published in Nature.
About Multiple Sclerosis (MS)
Many doctors consider multiple sclerosis (MS) to be an autoimmune condition, in which the body mistakenly attacks itself. In this case, the damage occurs on the myelin sheath, or the protective covering of nerve cells, causing exposed nerve fibers. Researchers estimate that slightly less than 1% of the total global population has MS. However, many cases are misdiagnosed or undiagnosed, so the true prevalence is somewhat unknown.
MS is a debilitating neurological disease which inhibits the way the brain communicates with the rest of the body. The condition may either be progressive (continuing without remission) or relapsing and remitting (periods of remission and periods of symptoms). Females are 2x more likely to develop MS than males. Additionally, while MS may occur during almost any age, it is most commonly diagnosed between ages 20 to 50. Symptoms associated with MS include:
- Muscle weakness
- Numbness and tingling throughout the body
- Loss of balance and coordination
- Lhermitte’s sign
- Loss of bladder control
- Constipation and fecal impaction
- Dizziness and vertigo
- Muscle spasms
What is Epstein-Barr Virus (EBV)?
The CDC explains that the Epstein-Barr virus (EBV), or human herpesvirus 4, is a common human virus that is found globally. EBV is spread through bodily fluids, so you can contract the virus through kissing, sexual contact, sharing food or drinks, or receiving blood or organ transplants. Many people become infected with EBV in childhood and the virus, even after you recover, lays dormant in your body. Typically, symptoms appear within 4-6 weeks following infection, and may last for an additional 2-4 weeks. In some cases, symptoms may last longer. EBV is associated with illnesses such as mononucleosis. Symptoms associated with EBV include:
- Sore, inflamed throat
- Enlarged spleen and liver
- Swollen lymph nodes in the neck
The Relationship Between EBV and MS
In the past, studies have shown that people with MS typically have heightened levels of viral antibodies, including antibodies to EBV, mumps, and measles. However, these same studies have failed to make a causal connection between viral infection and MS. Within this particular research, the research team examined blood and spinal fluid from nine individuals with multiple sclerosis. The researchers found that these individuals produced certain antibodies from B cells, which are found in spinal fluid.
Next, the research team made B cells express antibodies and then evaluated how these antibodies reacted to different antigens. An antigen is a toxin or other foreign substance within the body that prompts some sort of immune response. Findings include:
- 66% of patients had antibodies that became bound to EBNA1, with 88% having antibodies to even just EBNA1 fragments.
- After additional research, the team discovered that these same antibodies also bound to GlialCAM. Once the researchers expanded their research to additional patients, they discovered that anywhere from 20-25% of samples sourced from individuals with MS saw antibodies which highly reacted to both proteins.
- Prior studies highlighted how nearly all individuals involved in the studies had their MS begin after EBV infection.
- In mice models of multiple sclerosis, EBNA1 fragments caused more myelin sheath damage and paralysis, as well as a heightened immune response, compared to other proteins.
Moving forward, researchers believe that developing an EBV vaccination could help prevent against infection. Would this help reduce instances of multiple sclerosis? At this point, there are no concrete answers – though researchers now have a specific link between the two and can continue establishing this connection in the future.