MINI-review of Epstein-Barr virus involvement in multiple sclerosis etiology and pathogenesis.

Epstein-Barr virus (EBV) is the infectious agent that shows the strongest association with multiple sclerosis (MS). EBV is a ubiquitous double stranded DNA herpes virus that establishes a latent infection in B cells and is actively contained by the immune system throughout the life of its human host. Failure to control EBV infection can lead to the development of cancers and immunopathological diseases characterized by hyperreactive anti-EBV immune responses. Although MS is the result of still poorly understood interactions between genetic and environmental factors, compelling evidence indicates that EBV infection is essential for MS initiation. B cells are clearly key in the development of MS activity, given the extraordinary effectiveness of B cell depleting anti-CD20 monoclonal antibodies in relapsing MS patients. This commentary reviews the evidence supporting the link of EBV with MS and the mechanisms by which EBV might trigger MS and cause continued disease activity. Also discussed are trials of agents to reduce or eliminate EBV in humans, which are expected to provide additional insights into the role of EBV in ongoing MS pathology.