Extended observations on the association of HHV-6 and multiple sclerosis

Throughout the years, a long list of viruses has been associated with multi ple sclerosis (MS), however no virus to date has been definitively identifi ed as the etiologic agent of this disease. Recently, human herpesvirus 6 (H HV-6), a newly described herpesvirus, has been suggested to play a role in MS based on: immunohistochemical demonstration of HHV-6 in MS plaques, incr eased antibodies response to HHV-6 in sera and CSF of MS patients, and the demonstration of HHV-6 DNA in the serum of MS patients but not in normal in dividuals. To extend these observations we have focused our research in mul tiple directions. We have increased the number of MS patients tested for HH V-6 serum DNA providing confirmation of our previous study. Additionally we have investigated a possible correlation between HHV-6 viremia and clinica l activity. Finally to provide insight into the pathogenesis of this diseas e, we have begun to characterize the cellular immune response of MS patient s to HHV-6. Collectively these studies will help to define the role that HH V-6 may play in the pathogenesis of MS.