The virus XMRV has become a favorite topic in the scientific community -- three years after its initial discovery in prostate cancer tumors by researchers from the Cleveland Clinic and the University of California, San Francisco.

In October, a team of researchers from the Clinic, the University of Nevada at Reno and the National Cancer Institute reported finding the virus in the majority of patients they studied who had chronic fatigue syndrome. CFS is a debilitating disorder marked by profound fatigue, muscle pain, impaired memory and other symptoms. Its causes are unknown.

That news came on the heels of another study, published in September, that revealed the virus could be an important marker for aggressive prostate cancer tumors.

Capitalizing on the excitement and heightened spirit of collaboration, 75 of the top scientists nationwide studying XMRV are flying in to convene Wednesday at the Clinic.

"This is the first meeting of the major players in the area of XMRV," said John Coffin of the department of microbiology at Tufts University in Boston. "I think there's going to be a lot of excitement and a lot of new information presented."

XMRV is one of three known human retroviruses. The other two are HIV and HTLV (a type of virus that infects white blood cells and can cause leukemia and lymphoma). All three are transmitted through bodily fluids.

One of the most striking things about XMRV is that there are indications that up to 4 percent of people in the United States carry the virus, said Coffin, who wrote an editorial accompanying a journal article on the link to chronic fatigue syndrome. "There might be other consequences of this infection," he said.

The invitation-only gathering will be the first large meeting of scientists on XMRV since the National Institutes of Health's closed-door session last summer on the topic.

The National Cancer Institute helped pull together key people involved in various research projects, said Robert Silverman, a cancer biologist at the Clinic's Lerner Research Institute. "It's been about two months in the making."

It will be a chance for researchers not only to swap information but to form new collaborations.

"We're learning things at such a rapid pace that we need a venue to exchange ideas and information," said Dr. Ila Singh, a professor in the University of Utah's department of pathology and senior author of the research involving prostate cancer patients.

"I'm hoping for a deeper understanding. We know so little at the moment. I'm hoping to learn more about the virus," she said. "That's what's sorely lacking. There's a lot of speculative information . . . I want to know what's real."

In advance of Wednesday's meeting, Silverman, one of the researchers credited with the initial discovery of XMRV, spoke with The Plain Dealer:

How did XMRV get its name?

It's a descriptive name. Xenotropic, which means the virus came from mice but mice are immune to its effects. It does affect other animals. Murine leukemia, which is the parent virus. Related Virus.

How does XMRV affect animals?

XMRV is closely related to a virus that causes leukemia, lymphoma and neurological diseases in animals. [Research] suggests that the human version could cause similar disease.

How did humans acquire XMRV?

We probably acquired it from mice because that's where the prototype exists. At what point it crossed over to humans we don't know. It's probably something that's been out there for a long time. Maybe many years.

How is XMRV spread?

That research is in the planning stage. What we're doing is trying to develop diagnostic assays to assess who has it and who doesn't. We're trying to determine how the virus is transmitted.

With the new possible link to chronic fatigue syndrome, does this make getting funding for XMRV research easier?

The funding part remains to be seen. There's been a tremendous interest in chronic fatigue syndrome. I've been getting almost nonstop calls from doctors and patients. They're obviously looking for hope in this study, although the virus is not proven to cause CFS. That's still unknown. But until it's ruled out, it's going to obviously be a subject of great interest.

Have the research gains since your findings three years ago been significant enough that investigators are hopeful about what may be around the corner?

It was kind of a sleeper. We published in 2006. There were really only a handful of papers published in the first couple years. It takes time for scientists to mobilize and perform research. Now there's a flurry of publications working on it. The field is exploding. It depends on whether we can nail down if this is a disease-causing virus. The potential of this is enormous. If it is proven to cause prostate cancer or chronic fatigue syndrome, then there would be the potential for new methods of diagnosis, new methods of treatment -- antivirals, even for prevention. That's why we're so excited about the prospect.

What about the recent study by German researchers in the journal Retrovirology that found no link between XMRV and prostate cancer?

It is not atypical of science for different groups to get different results. There could be methodological differences. I believe our methods were more sensitive. They may have missed it. Or it could be a different strain. Another interpretation is that the virus is more prevalent in the United States than in Germany.

Why should the average person care about XMRV?

We don't know at this point if the virus causes either prostate cancer or chronic fatigue syndrome. Our results suggest that XMRV is a candidate for causing human disease. However, it's still in a relatively early stage of the research. There are potentially major public health implications of this virus, so there's an urgency to figure it out and move forward.

What is the Clinic working on now in relation to XMRV?

We're working to help develop a diagnostic test that could be applied to a large number of people. It could be developed pretty quickly, maybe in a year or two.

We're really studying how the virus could cause disease at a very fundamental level. But a vaccine could be 10 years [away] or maybe longer.

This is exciting research. We're working as hard as we can to help benefit patients.

Contact Angela Townsend: atownsen@plaind.com or 216-999-3894.