Human herpesvirus 6 is latent in peripheral blood of patients with relapsing-remitting multiple sclerosis

Studies of the association between HHV-6 and multiple sclerosis are hindere d by the difficulty in discriminating between latent and active infection. A follow up study was undertaken of patients with multiple sclerosis, searc hing peripheral blood mononuclear cells for molecular markers associated wi th HHV-6 latency and lytic replication. The results show that HHV-6 is late nt and did not support systemic infection in patients with multiple scleros is. Likewise, patients with multiple sclerosis did not show any evidence of active infection with other human herpesviruses HHV-7 and HHV-8.