WSJ's blog on XMRV

By Amy Dockser Marcus, The Wall Street Journal

The controversy surrounding XMRV, a virus that has been linked to chronic-fatigue syndrome and prostate cancer, has been heating up recently.

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 results of the published studies have led to greater scrutiny of the way CFS is defined.

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.