Barr virus on

William H. Robinson and Lawrence Steinman of Stanford University wrote in an editorial accompanying Thursday's study.

But they cautioned, "additional fuses must be ignited," such as genes that may make people more vulnerable. Epstein-Barr is best known for causing "mono," or infectious mononucleosis, in teens and young adults but often occurs with no symptoms. A virus that remains inactive in the body after initial infection, it also has been linked to later development of some autoimmune diseases and rare cancers.

It's not clear why. Among the possibilities is what's called "molecular mimicry," meaning viral proteins may look so similar to some nervous system proteins that it induces the mistaken immune attack. The new Harvard research wasn't a randomized trial that could prove cause and effect, but the link suggested by the findings makes it "the strongest evidence to date that Epstein-Barr contributes to cause MS," said Mark Allegretta, vice president for research at the National Multiple Sclerosis Society.

And that, he added, "opens the door to potentially prevent MS by preventing Epstein-Barr infection. Attempts are underway to develop Epstein-Barr vaccines, including a small study just started by Moderna, the company now best known for its COVID vaccine. The team was looking for seroconversion, or the appearance of antibodies in the blood as evidence of infection.

Each person with MS was also matched with two randomly selected controls without MS, who were of the same age, sex, race or ethnicity, and branch of the military. Out of the cases of MS, they were able to assemble appropriate samples for individuals with the disease and 1, controls. The risk of developing MS was 32 times greater for those who seroconverted by the third sample, compared with those who did not.

As for the one case of MS in someone who remained negative for Epstein-Barr, it is possible that person was infected after the sample was taken, but it is also true that, in diseases that are clinically defined by their symptoms, such as MS, it is highly unlikely that percent of cases derive from the same cause, even if most do, Ascherio says.

But to be sure Epstein-Barr was the culprit, Ascherio and his colleagues also measured antibodies against cytomegalovirus, another herpesvirus, and found no difference in levels in those who developed MS and those who did not. Using a subset of 30 MS cases and 30 controls, they conducted a scan to detect antibody responses to most of the viruses that infect humans. Again, there was no difference. And to rule out the possibility that infection with Epstein-Barr preceded MS and not the other way around, the team also measured levels of a protein that is elevated in serum when neurons are injured or die and that therefore serves as a marker of the beginning of the pathological process before clinical symptoms appear.

The protein levels only rose after Epstein-Barr infection. One major question remains, however: How does the virus lead to the disease?

They proposed several possibilities, such as inducing an autoimmune reaction. Even if Epstein-Barr is the triggering event for MS, infection alone is insufficient for an actual diagnosis. Epstein-Barr, it appears, has to combine with a genetic predisposition and possibly environmental factors, such as smoking and vitamin D deficiency, to increase risk.

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Menu Search Home Diseases Chronic active Epstein-Barr virus infection. You can help advance rare disease research! This site is in-development and may not reflect the final version. Preview the new GARD site. Other Names:. Viral infections. Summary Summary. Symptoms Symptoms. These features may be different from person to person. Some people may have more symptoms than others and symptoms can range from mild to severe.

This list does not include every symptom or feature that has been described in this condition. Over time, CAEBV can lead to failure of the immune system which, if not treated, can lead to potentially life-threatening complications. Showing of 8 View All. Permanent enlargement of the airways of the lungs. Decreased immune function. Frequent respiratory infections. Multiple respiratory infections.

Susceptibility to respiratory infections. Sinus inflammation. Increased spleen size. Do you have more information about symptoms of this disease? We want to hear from you. Cause Cause.