Human herpesvirus 6 and effectiveness of interferon beta 1b in multiple sclerosis patients

Garcia-Montojo et al. Eur J Neurol. 2011 Apr 25.

Human herpesvirus 6 (HHV-6) and Epstein-Barr virus (EBV) are associated with MS. Once infected with these viruses you remain infected with them for life. These viruses have a latent or dormant phase, were they hibernate within the body, and an active or lytic phase characterised by viral replication. IFN-beta may work via its antiviral properties suppressing the replication of these viruses within the body. This study evaluated the effects of IFN-beta-1b on the levels of HHV-6 and EBV in the blood of PwMS. Patients with detectable HHV-6 in their blood had a higher risk of severe relapses and a poor response to IFN-beta-1b. HHV-6 was detected in the blood more frequently during relapses than in periods of remission. No association was found between EBV and any of the clinical parameters studied. The authors' concluded that presence of HHV-6 in blood, and not EBV, during IFN-beta treatment could be a potential marker of poor response to IFN-beta-1b.

"The link between detectable HHV-6 in the blood and poor response to IFN-beta may simply be due to an association with another factor, rather than being causal; i.e. whatever is causing the lack of MS response to INFbeta may also be causing the lack of HHV-6 response to the anti-viral effects.

There are some methodological problems with this study.

As always these findings will need to be replicated by independent investigators in other groups of patients. Reproducibility and consistent results is what makes science sticky; something the CCSVI fraternity seem to ignore."