by Martin Enserink on 18 September 2012, 2:08 PM
Coming around. "It's simply not there," Judy Mikovits said at a press
conference this morning.
Credit: Columbia University
You could be forgiven for thinking that the story of XMRV, a mouse
retrovirus implicated in chronic fatigue syndrome (CFS), is over.
After all, study after study has failed to replicate the XMRV-CFS
link, and last year, Science retracted the 2009 paper in which XMRV
was first fingered as a cause of the elusive syndrome. Most
researchers concluded long ago that those findings resulted from an
accidental contamination of patient samples in the lab.
But until now, the biggest study on the topic still hadn't been
wrapped up: a project funded by the U.S. National Institutes of Health
(NIH) and led by Ian Lipkin of Columbia University that brought
together supporters and skeptics of the theory that XMRV plays a role
in chronic fatigue. Today, mBio published the results of the study,
which proves that, as most scientists suspected, the XMRV theory is
most definitely dead.
This time, even Judy Mikovits, the chief author of the 2009 study and
the main protagonist in the twisted scientific saga, agrees. Mikovits,
formerly at the Whittemore Peterson Institute (WPI) in Reno, Nevada,
participated in Lipkin's study and concedes that it is "the definitive
answer. … There is no evidence that XMRV is a human pathogen."
Three research groups took part in the mBio study: Mikovits, along
with her collaborators Francis Ruscetti at the National Cancer
Institute and Maureen Hanson at Cornell University; a team led by
Shyh-Ching Lo at the Food and Drug Administration, which linked CFS to
a related group of viruses called MLVs in a study that was also
retracted; and a group at the Centers for Disease Control and
Prevention, which had failed to find the virus in CFS patient samples.
Each group was presented with samples from 147 patients and 146
healthy controls from six U.S. cities. Each was free to analyze
samples using its own techniques; that way, no one could complain that
the right methods weren't used, Lipkin says. The samples were blinded
until all the analyses were done.
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Mikovits's participation in the study was complicated by the fact that
she was fired by WPI in September of 2011 and later arrested, jailed,
and charged with illegally taking data and related property from WPI.
(The criminal charges, which came on top of a civil suit by WPI, were
dropped in June.) Antibody testing for Mikovits's share of the study
was done at Ruscetti's lab and PCR tests at Hanson's lab.
None of the groups found any trace of XMRV or MLVs whatsoever—neither
in patients nor controls. Mikovits and Ruscetti did find that about 6%
of patients and controls had antibodies that reacted to XMRV—a result
that they chalk up to aspecific binding instead of XMRV infection.
As to XMRV, "it's simply not there," Mikovits said at a press
conference this morning to announce the results of the new study. No
previous study had tried to replicate her findings using her exact
methods, Mikovits says. "I'm forever grateful to Ian Lipkin for making
it possible to participate," she says. Lipkin says he is "proud" of
Mikovits for accepting the outcome and asked the audience at the press
conference to give her a round of applause.
The outcome isn't surprising, says Vinay Pathak of the National Cancer
Institute, one of the authors of a key study last year that showed
XMRV was accidentally created in the lab. Still, Pathak says, Lipkin's
study is a "model" for how similar disputes can be resolved in the
future. Kim McCleary, the head of the CFIDS Association of America, a
CFS advocacy group, hopes the study will finally bring closure to the
debate about XMRV.
Samples gathered for the new study will also be available for other
researchers, which is a "silver lining for an ultimately disappointing
outcome," McCleary says. "We hope that people from all over the world
will use these samples," Lipkin said this morning.