For immediate release: January 13, 2022
Boston, MA – Multiple sclerosis (MS), a progressive disease that affects 2.8 million people worldwide and for which there is no definitive treatment, is likely caused by infection with the Epstein virus- Barr (EBV), according to a study by Harvard Researchers from the TH Chan School of Public Health.
Their findings were published online in Science on January 13, 2022.
“The hypothesis that EBV causes MS has been studied by our group and others for several years, but this is the first study providing convincing evidence of causation,” said Alberto Ascherio, professor of in Epidemiology and Nutrition at Harvard Chan School and lead author of the study. to study. “This is a big step forward as it suggests that most cases of MS could be prevented by stopping EBV infection, and that targeting EBV could lead to the discovery of a cure. against MS.
MS is a chronic inflammatory disease of the central nervous system that attacks the myelin sheaths protecting neurons in the brain and spinal cord. Its cause is not known, but one of the main suspects is EBV, a herpes virus that can cause infectious mononucleosis and establish a latent and permanent infection of the host. It has been difficult to establish a causal relationship between the virus and the disease because EBV infects about 95% of adults, MS is a relatively rare disease, and the onset of MS symptoms begins about 10 years after EBV infection. To determine the link between EBV and MS, researchers conducted a study of more than 10 million active duty young adults in the U.S. military and identified 955 who were diagnosed with MS during their service period.
The team analyzed serum samples collected every two years by the military and determined the soldiers’ EBV status at the time of the first sample and the relationship between EBV infection and the onset of MS during the period. of active duty. In this cohort, the risk of MS increased 32-fold after infection with EBV but remained unchanged after infection with other viruses. Serum levels of neurofilament light chain, a biomarker of nerve degeneration typical of MS, only increased after EBV infection. The results cannot be explained by any known risk factors for MS and suggest that EBV is the main cause of MS.
Ascherio says the delay between EBV infection and the onset of MS may be partly due to disease symptoms going undetected in the early stages and partly due to the progression of the relationship between EBV and the host’s immune system, which is repeatedly stimulated each time the latent virus reactivates. .
“Currently, there is no way to effectively prevent or treat EBV infection, but an EBV vaccine or targeting the virus with EBV-specific antiviral drugs could ultimately prevent or cure MS. “, said Ascherio.
Other Harvard Chan School researchers who contributed to this study include Kjetil Bjornevik, Marianna Cortese, Michael Mina, and Kassandra Munger.
Funding for this study came from the National Institute of Neurological Disorders and Stroke, the National Institutes of Health (NS046635, NS042194, and NS103891), the National Multiple Sclerosis Society (PP-1912-35234), the German Research Foundation (CO 2129/1-1), the National Institutes of Health (DP5-OD028145) and the Howard Hughes Medical Institute.
“Longitudinal Analysis Reveals High Prevalence of Epstein-Barr Virus Associated with Multiple Sclerosis”, Kjetil Bjornevik, Marianna Cortese, Brian C. Healy, Jens Kuhle, Michael J. Mina, Yumei Leng, Stephen J. Elledge , David W. Niebuhr, Ann I. Scher, Kassandra L. Munger, Alberto Ascherio, Science, 13 Jan 2022, doi: 10.1126/science.abj8222
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Harvard TH Chan School of Public Health brings together dedicated experts from many disciplines to educate new generations of global health leaders and generate powerful ideas that improve the lives and health of people everywhere. As a community of leading scientists, educators and students, we work together to bring innovative ideas from the lab to people’s lives, not only achieving scientific breakthroughs, but also working to change the individual behaviors, public policies and health care practices. Each year, more than 400 Harvard Chan School faculty members teach more than 1,000 full-time students from around the world and train thousands more through online and executive education courses. Founded in 1913 as the Harvard-MIT School of Health Officers, the school is recognized as America’s oldest professional public health training program.