The controversy surrounding XMRV, a virus that has been linked to
chronic-fatigue syndrome and prostate cancer, has been heating up
Earlier this month, CDC researchers published a paper in Retrovirology
that reported the absence of XMRV in either the CFS patients studied
or healthy controls. A much-anticipated study by researchers from the
FDA and NIH supposedly reached a different conclusion, finding the
virus in the blood of CFS patients. It's expected to run in the
journal PNAS but has yet to be published.
So lots of people are waiting for answers — patients anxious to find
out whether their disease is linked to XMRV, scientists interested in
learning more about what is only the third known human retrovirus and
public health officials trying to determine whether XMRV could affect
the nation's blood supply.
And that wait may not be a short one, say experts participating in a
webinar today sponsored by the advocacy group CFIDS Association of
America. Vincent Racaniello, a professor of microbiology and
immunology at Columbia University, said that there's a lot of work yet
to be done in patients in order to answer the key questions
surrounding the issue, and the full dimensions of the XMRV story will
take time to understand.
"We can learn a lot from history," he said on the webinar, noting that
it took 15 years from the time clusters of AIDS patients were
identified to the development of effective therapies. Racaniello
doesn't study XMRV in the lab, but he blogs about the controversy.
In a follow-up chat with the Health Blog, Racaniello said that so far,
all the published studies have been done in relatively small numbers
of patients — 50 or 100 people.
What's needed to really get answers, he says, is a 500- or 1,000-
person, federally funded study conducted at more than one research
site. Ideally participants would be existing CFS patients who'd be
available to be interviewed for detailed medical and case histories,
and who could give fresh blood samples. And centers would use uniform
definitions of CFS and lab methods, he said.
Another webinar participant, Lucinda Bateman, an internist who
evaluates CFS patients at her Salt Lake City clinic, says that up
until now there's been "no consistency in the way we diagnose and
treat patients" with CFS. Potential treatments for XMRV infection
exist, she says, but there are plenty of questions about which are
safe and effective — and sorting all that out will take (you guessed
it!) — time.
Still, that's not to say that the scientific process — and the debate
— hasn't been fruitful, she says. Even negative studies help shape the
direction of future research, and the differing resultsof the
published studies have led to greater scrutiny of the way CFS is
Interest in CFS is growing in major academic centers and attracting
more scientists. And more people are donating money to help fund CFS
research, she adds — which eventually should lead to the kinds of
trials that Racaniello and others want to see done.