Emerg Infect Dis. 2011 Feb;17(2):314-5.
No Xenotropic Murine Leukemia Virus-related Virus Detected in Fibromyalgia Patients.
Luczkowiak J, Sierra O, Gonzalez-Martin JJ, Herrero-Beaumont G, Delgado R.
Hospital Universitario 12 de Octubre, Madrid, Spain (J. Luczkowiak, O. Sierra, R. Delgado); and IIS-Fundacion Jimenez Diaz, Madrid (J.J. Gonzalez-Martin, G. Herrero-Beaumont).
Xenotropic murine leukemia virus-related virus (XMRV) is a recently described human retrovirus that has been associated with prostate cancer and chronic fatigue syndrome (CFS) (1,2). XMRV is similar to a classic murine endogenous leukemia retrovirus, murine leukemia virus (MLV), which infects strains of mice that do not express the specific viral receptor. XMRV is genetically close to, although differentiable from, MLV. The first evidence of its presence in humans was obtained by Urisman et al. in prostate cancer tissue (1). In 2009, Lombardi et al. (2) found XMRV sequences and specific antibody responses in 67% of a large group of patients with CFS in North America. This association was notable because XMRV sequences were found in only 4% of healthy controls. These results have generated controversy because several independent studies, mainly in Europe (3-5) but also in North America (6), have been unable to detect XMRV sequences in patients with CFS. Furthermore, a recent report from North America (7) appears to confirm the initial results by Lombardi et al. (2) in patients with CFS and expands the viral association to a wider variety of XMLV-related viruses that seem closer to polytropic mouse endogenous retroviruses.