Researchers from the Harvard School of Public Health and the Walter Reed Army Institute of Research have linked elevated blood levels of antibodies that fight Epstein-Barr virus (EBV) antigens with the future development of multiple sclerosis (MS). The findings appear as a Brief Report in the March 26 issue of The Journal of the American Medical Association.
The authors found increased antibody response to EBV occurs early in relation to the pathological process leading to MS and years before the onset of the first symptoms of MS. While the research implies a role for EBV in MS, it doesn’t show a cause and effect relationship. Further study is needed to demonstrate a plausible biological process.
The researchers identified 83 cases of MS that occurred among more than 3 million U.S. military personnel whose blood samples had been collected and stored by the Department of Defense. For each case, the earliest blood sample and up to two additional samples taken before the onset of MS were available along with the first sample taken after the onset. For each case of MS, a randomly selected control without MS was assigned matched by age, gender, ethnicity, and dates of blood sample collection.
The researchers found that the risk of MS rose steadily in individuals with increasing blood levels of antibodies for Epstein-Barr Nuclear Antigen (EBNA) and Viral Capsid Antigen (VCA, found in blood serum of individuals who have been infected with EBV). The risk of developing MS was over 30 times higher for individuals with the highest levels of anti-EBNA antibodies than for individuals with the lowest levels.
Epstein-Barr virus, a member of the herpesvirus family, is one of the most common viruses in the world, infecting as many as 95 percent of adults in the United States by age 40. Most people become infected at some point in their lives and show no symptoms. EBV infection during adolescence or early adulthood can cause infectious mononucleosis up to 50 percent of the time.
Multiple sclerosis is a chronic degenerative disease of the central nervous system. The prevalence rate in the United States is higher for individuals who live above the 37th parallel, accounting for 110 to 140 cases per 100,000 people, compared with 60-80 cases per 100,000 for people living below the 37th parallel. Nationwide, an estimated 250,000 to 350,000 people have MS.