Human Herpes Virus-6 (HHV6) as a risk factor of Relapsing and Remmiting Multiple Sclerosis in a sample of Egyptian Patients

Abstract

M ultiple sclerosis (MS) is a chronic autoimmune illness of the central nervous system (CNS). It is the most common autoimmune disease in young adult with peak incidence between the ages of 20 and 40 years. A viral trigger involved in multiple sclerosis has been suggested more than 100 years ago and an extensive list of candidate viruses has emerged since then. The frequency of HHV-6 specific IgG (measuring latent infection) in normal population was 76.4%, relatively consistent with the average global frequency of 90%, HHV-6 may directly lyses and thus destroys infected target cells or it may induce inflammatory and autoimmune reactions. These can be mediated by a large variety of HHV 6-induced or altered cytokine and chemokine patterns as well as by modulation of cell membrane receptors. Various reports using different methods have linked HHV-6 to MS, much of these reports were case-control studies detecting higher prevalence of HHV-6 in MS patients compared to control individuals. Interestingly, a successful treatment of MS involves the injection of b-interferon, which is also an antiviral and immunomodulatory cytokine.