An attempt to investigate the presence of Epstein Barr virus in multiple sclerosis and normal control brain tissue

Multiple Sclerosis (MS) is an important demyelinating disease of the central nervous system, the aetiology of which may possibly have a viral component at some stage. In this study we investigated the possible involvement in MS of the human herpes virus Epstein Barr Virus (EBV). Utilising both fluorescent and non-fluorescent in situ hybridisation (FISH) techniques, we examined human post mortem tissues obtained from a tissue bank for the presence of immediate early and late viral gene and protein expression in MS patient normal appearing white matter (NAWM), lesional tissue and normal control brain samples. The technique of mRNA FISH showed that many of the tissues were largely degraded and therefore could not provide any evidence of viral gene expression. Some weak scattered signals, however, were seen in mRNA ISH for both lytic and latent gene transcription in all three tissue categories. The failure of IF and mRNA FISH in the majority of samples alongside the poor signal for mRNA ISH precluded any definite conclusions to be made as to the possible ongoing involvement of EBV in MS. While certainly not ruling out a possible role of EBV in MS, especially in the context of a 'hit and run' mechanism, these studies illustrate the difficulties of using autopsy tissues for molecular studies when tissue preservation is sub-optimal. Nevertheless, the limited data obtained did not provide any positive evidence of EBV involvement.