Thursday, July 15, 2010

WSJ Blog on XMRV

Potential XMRV-Chronic Fatigue Syndrome Link Not Easy to Tease Out -  Health Blog - WSJ

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.

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