Novel human herpesviruses and multiple sclerosis

It has been suggested that human herpesvirus 6 (HHV-6) might be involved in the pathogenesis of multiple sclerosis (MS). However, studies of the assoc iation between HHV-6 and MS are hindered by the difficulty in discriminatin g between latent and active infection. We undertook a study to determine wh ether HHV-6 establish a systemic active infection in the course of MS, and to investigate possible roles of HHV-7, a herpesvirus closely related to HH V-6. To discriminate between latent and active infection, we analysed viral transcription. The results indicate that both viruses are prevalent in PBM Cs of MS patients as in healthy controls, and that viral sequences are main tained in a non-trascriptional state. These observations indicate that furt her studies should define the state of viral persistence in the central ner vous system.