New research has found evidence that Epstein-Barr virus (EBV) infection may be a cause of multiple sclerosis (MS), an autoimmune disease that leads to the loss of the myelin sheath around nerve cells. In addition to EBV’s link to the development of MS and other autoimmune diseases, it’s a known risk factor for certain cancers.
EBV is an extremely common human herpes virus and a common cause of infectious mononucleosis (also called “mono”). According to an article published in the journal Science, more than 90 percent of the adult population worldwide has been exposed to EBV at some point in their lives, usually as children or young adults, but many people never have any symptoms.
EBV can infect epithelial cells that line the mouth and throat, as well as B lymphocytes (B cells), white blood cells that make antibodies. However, the virus can remain dormant (inactive).
EBV infection has been linked to many diseases that involve the immune system. Autoimmune diseases linked to EBV include MS, rheumatoid arthritis, and systemic lupus erythematosus — also simply called lupus. Autoimmune diseases are those in which a person’s immune system attacks healthy cells as if they were viruses, bacteria, or cancer. EBV is also linked to certain cancers, including stomach cancer, nasopharyngeal carcinoma, and several types of lymphoma, including some T-cell lymphomas.
EBV was first discovered in cancer cells in 1964, making it the first virus found in humans that is known to cause cancer. Other viruses, including human papillomavirus (HPV), hepatitis B and C, and HIV, have also been found to cause specific cancers since the discovery of EBV.
Two of the most common cancers associated with EBV are endemic Burkitt’s lymphoma in Africa and nasopharyngeal carcinoma, but these cancers appear to be largely due to a specific strain of EBV. Other types of cancer that can be caused by EBV include Hodgkin lymphoma, several types of non-Hodgkin lymphoma, a type of stomach cancer, and some cancers seen in those who are immunocompromised.
Although most people have been exposed to EBV, EBV-related cancers are relatively rare, accounting for only about 1 percent of all cancers. EBV infection is a risk factor for these cancers, but research suggests the combination of EBV with genetic and environmental factors, such as environmental exposures, increases cancer risk.
Studies of cancer risk in people with MS have found conflicting results. Some researchers have found no increased risk of cancer in those with MS, and others have found an increased risk of certain cancers.
One study in the journal Neurology found a link between MS and higher rates of bladder cancer and central nervous system (CNS) cancer but also found lower rates of prostate and uterine cancer with MS.
Another study found that people with MS had a higher overall cancer risk, including a higher risk of cancers in the CNS, respiratory organs, and urinary organs. The same study also found an increased risk of blood cancers in siblings of people with MS, including the types of cancers associated with EBV infection. This finding suggests that EBV, MS, and certain cancers may all be somehow related.
Disease-modifying therapies (DMTs) for MS may be linked to an increased risk of cancer. DMTs for MS include drugs that suppress the immune system, which can increase a person’s risk of viral infections and cancers that the immune system would normally fight.
Research has found a link between MS, lupus, viral infections, and cancer risk. Researchers found that people with MS or lupus had a higher rate of infections with cancer-related viruses compared to the general population.
This research suggests that an abnormal immune system in people with MS contributes to increased viral infections and cancer — the immune system is attacking the body and not fighting infection and cancer as it should. DMTs to treat MS may add to this risk by further decreasing the immune system's ability to fight infection and cancer.
Although there is not much you can do to lower your risk of getting EBV, there are some suggestions from the Mayo Clinic that you can take to decrease your overall cancer risk, whether or not you have MS:
There are no guarantees that making healthy choices will prevent you from developing cancer, but they can lower your risk of cancer and other diseases, such as diabetes and heart disease.
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Are you or someone you care for living with EBV, MS, or MS and cancer? Share your experience in the comments below, or start a conversation by posting on your Activities page.