[Multiple sclerosis and Epstein-Barr virus : new developments and perspectives].

Data from studies of twins and migrants with multiple sclerosis (MS) imply environmental factors in the development of MS. In this respect, increasing evidence indicates that Epstein-Barr virus (EBV) plays a unique role as an infectious risk factor for MS. A nearly 100% seroprevalence of antibodies to EBV in patients with MS, elevated EBV antibody titers years before clinical onset of the disease, and an increased risk for MS after symptomatic primary EBV infection (infectious mononucleosis) suggest an association of MS with a previous infection with EBV. However, the precise mechanisms through which EBV may contribute to MS are still unclear. Currently discussed potential mechanisms are outlined. The notion of a persisting (possibly immunological) change caused during the acute phase of primary EBV infection and subsequently leading to permanently elevated MS risk appears compatible with several aspects of the association found between MS and EBV.