Chronic fatigue syndrome (CFS) is a somewhat mysterious condition, as while it causes serious impairment, the cause is currently unknown, and there is no known cure. The illness, which is characterized by a constellation of symptoms including incapacitating exhaustion, cognitive problems, nonrestorative sleep, and severe exercise intolerance (when exercise makes symptoms worse), is thought to occur 4 times more frequently in women than in men. A new paper published by the journal Science suggests an association between chronic fatigue syndrome and a virus previously associated with prostate cancer. The virus in question is xenotropic murine leukemia virus-related virus (XMRV).
For the study, the researchers examined samples from 101 patients with chronic fatigue syndrome and 218 healthy controls to see if they could detect the virus. They were able to detect the virus in 67% of those with CFS, and 3.7% of controls, leading them to conclude that the virus is perhaps somehow associated with the disease.
The link between XMRV and either prostate cancer or chronic fatigue syndrome is not fully understood and may not be causative. The authors of the current study themselves conclude with several questions about whether the virus is a causal factor for CFS or simply more readily hosted in immunosuppressed patients. In a commentary on the findings for Science, two authors write:
There is still much that we do not understand. Whether the virus plays a causative role in either chronic fatigue syndrome or prostate cancer is unknown. For example, XMRV infection might, coincidentally, be more frequent in the same geographical region as a cluster of patients with chronic fatigue syndrome. And individuals with either disease might be more readily infected due to immune activation.
The research team plans further investigation into the association, including whether – because both are a type of virus called a retrovirus – drugs for the treatment of HIV may have some effect against CFS.
Scientific American and Not Exactly Rocket Science (at ScienceBlogs) have additional summary with discussion in the comments. For more information on Chronic Fatigue Syndrome, see the webpage of the CFIDS Association of America.