Absence of xenotropic murine leukaemia virus-related virus in Danish patients with multiple sclerosis

Background Detection of a novel Gammaretrovirus, Xenotropic Murine leukaemia virus-Related Virus (XMRV) has been reported in peripheral blood mononuclear cells of patients with chronic fatigue syndrome, and in prostate cancer tissue. As Multiple Sclerosis (MS) is a disease with retroviral association (human endogenous retroviruses (HERVs)), we investigated whether XMRV could be contributing to MS aetiology by testing a well defined cohort of Danish MS patients for the presence of XMRV sequences.