When I first heard that a retrovirus had been identified as a possible cause of chronic fatigue syndrome, I withheld judgment and awaited further developments. When I heard that two subsequent studies had failed to replicate the findings of the first, I assumed that the first had been a false alarm and would be disregarded. Not so.
It’s a classic case of wishful thinking outweighing good judgment. One unconfirmed report of an association between the XMRV virus and chronic fatigue syndrome (CFS) resulted in a rush to test for the virus, speculation about possible implications, and even suggestions for treatment. And the subsequent negative studies did little or nothing to reverse the trend.
XMRV is Xenotropic murine leukemia virus-related virus. In the past, there were reports that this retrovirus was associated with prostate cancer, but then other reports found no link. In 2009 a study was published in Science, “Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome” by Lombardi et al., reporting an association with CFS:
we identified DNA from a human gammaretrovirus, xenotropic murine leukemia virus–related virus (XMRV), in 68 of 101 patients (67%) as compared to 8 of 218 (3.7%) healthy controls. (more…)