Controversial role of Epstein-Barr virus in multiple sclerosis

The role of Epstein-Barr virus (EBV) in the pathogenesis of multiple sclerosis (MS) is still elusive. In 2007, Serafini et al demonstrated the direct role of EBV in brain lesions of MS patients. They found positive immunohistochemistry (IHC) staining for latency membrane protein 1 (LMP1), and EBV-encoded RNA (EBER) by in-situ hybridization (ISH) within postmortem brains of MS patients. The goal of this study was to attempt to demonstrate LMP1 by IHC and EBER by ISH in brains of patients with MS, to either support or refute their findings. Seventeen MS (16 brain biopsies and 1 autopsy brain) and 12 autopsy brains with no pathologic abnormalities, as normal controls, were studied. To control for the possibility that inflammation owing to other etiologies could result in EBV-positive cell accumulation, 11 brain biopsies of encephalitis and 4 brain biopsies of progressive multifocal leukoencephalopathy were also studied. Known positive (Hodgkins and non-Hodgkins lymphoma) and negative (with antibody primary replaced by buffer) controls were used. All positive and negative controls showed appropriate staining. However, there were no positive LMP1 or EBER results in any of the groups studied. The negative results of IHC and ISH in our study sharply contrast to those previously mentioned by Serafini et al, 2007 and suggest that EBV is not directly related to MS as an etiology.