The mouse virus XMRV is not associated with chronic fatigue syndrome (CFS), according to a blue-ribbon study that included the researcher who first proposed the link.
Gene sequences from XMRV and a closely related virus called polytropic murine leukemia virus (pMLV) could not be found in blood samples either from 147 patients with confirmed chronic fatigue syndrome — also known as myalgic encephalitis (ME) — or from 146 healthy volunteers, reported W. Ian Lipkin, MD, PhD, of Columbia University in New York City, and colleagues online in mBio.
Source: MedPage Today
So, the suspected virus was again not found. The results ruled out past exposure to the viruses as causing the illness.
What does this mean?
I asked friend and informed skeptic Joey Haban to tell us:
The history of XMRV and chronic fatigue syndrome (CFS) is a long, weird one. Judy Mikovits, a researcher at the Whittemore-Peterson Institute for Neuro-Immune Disease in Nevada (WPI), first published research in 2009 indicating a connection between the mouse retrovirus and the illness. While the first priority of researchers was to attempt replication of those results, some of the patient community accepted these results immediately and permanently, creating something of a cult of personality around Mikovits.
As the link above describes, other labs were unable to replicate the XMRV connection, and researchers began to move on to other studies of CFS and myalgic encephalomyopathy (ME).
Eventually, Mikovits’ and Lo’s papers were retracted — in the first instance by Science’s editors, in the second by Lo and colleagues on their own initiative. In a largely unrelated sideshow, Mikovits was also fired from the Whittemore Peterson Institute, whose leaders then had her arrested for allegedly taking lab notebooks and computers belonging to the organization, although the criminal charges were later dropped.
Mikovits became almost an Andrew Wakefield figure, as she prematurely started to suggest connections between XMRV and everything from MS to autism. She even presented at the dismally anti-vax and anti-science AutismOne conference – alongside Wakefield himself. Labs – including one affiliated with WPI – began offering XMRV tests and some doctors began treating patients with dangerous anti-retrovirals. Community supporters of the XMRV theory became more extreme as the evidence waned, actually threatening scientists with whom they disagreed and developing conspiracy theories around the discrediting of Mikovits. Sadly, these vocal XMRV stalwarts badly stained public perception of the community, and energized those who still believe ME/CFS to be a mental disorder.
Today, the large multicenter study by Lipkin et al put the CFS-XMRV connection to bed at last, and in a press conference, both Lipkin and Mikovits herself announced that it’s time to move on. The media immediately set to work confusing the matter. The Nursing Times and other publications announced “No viruses linked to CFS.” The New York Times even pronounced that CFS “is back to square one,” which couldn’t be less true; excitement over XMRV turned into more biomedical research than ever into ME/CFS, which has conclusively disproven the long-held myth that the illness is psychological in nature. New drugs are being tested, and the FDA has classified ME/CFS as a “serious and life-threatening condition”, which will help expedite their review.
The important points to take away from this study and the press conference are that the two specific retroviruses studied do not have a link to ME/CFS. However, there may well be some kind of viral link or trigger. There has been an increase in research into ME/CFS, much of it focusing on common biomedical links among patients, such as certain proteins in the cerebrospinal fluid. Science has done its job and definitively shut down the posited XMRV-CFS link. While the extremists in the patient community will continue with their outlandish theories and outrage, they do not represent most patients, who are looking forward to the truly promising areas of research that have arisen in the wake of this saga.
[Editor: Thanks, Joey!]