23 August 2010

Study Finds Retroviruses in Chronic Fatigue Sufferers

The Wall Street Journal

Researchers said Monday they have identified a family of retroviruses in patients with chronic fatigue syndrome, a finding that is likely to spur patients with the condition to seek treatment with drugs used to fight HIV, the virus that causes AIDS.

The report, published in the Proceedings of the National Academy of Sciences, was accompanied by a call for new clinical trials to test HIV drugs in patients with chronic fatigue syndrome, which afflicts an estimated one million to four million Americans and as many as 17 million people world-wide.

Although HIV and the newly identified virus group are different, both are retroviruses. Based on other recent research linking CFS to a retrovirus called XMRV, some doctors are already prescribing drugs approved for HIV for CFS patients. The syndrome has no known cause and there aren't any effective treatments.

The group of viruses, called murine leukemia virus-related viruses, or MLV, are known to cause cancer and neurological problems in mice, but whether they cause any diseases in humans isn't known. XMRV is among several different members of the MLV family, researchers said.

In the new study, researchers said they found at least one of four different MLV-like viruses in 32 of 37, or 86.5% of patients with chronic fatigue syndrome, compared with just three of 44, or 6.8%, of apparently healthy volunteer blood donors.

The paper is the latest in a series of reports about a possible link between CFS and a virus. Previous studies have focused on XMRV and have turned up conflicting evidence. Indeed, the just-published study was held back from publication in June because it was at odds with a report from the Centers for Disease Control and Prevention, which found no evidence of XMRV in chronic fatigue syndrome patients.

The current paper didn't find XMRV either—one reason it isn't likely to resolve a brewing debate over the role that XMRV may play in the syndrome. But researchers said the variants of MLV-like viruses closely related to XMRV they found in CFS patients was evidence of a link between the virus family and the syndome.

Andrew Mason, a University of Alberta professor, co-wrote the commentary in PNAS calling for trials testing anti-retrovirals in CFS patients who are positive for one of the MLV-related viruses. "If the patients improve, after a certain point you stop debating whether it causes the disease and say the treatment works and we're going to use it,'' said Dr. Mason.

But until further evidence establishing that the virus causes CFS is developed, a large-scale clinical trial testing HIV drugs against the syndrome isn't likely. Norbert Bischofberger, chief scientific officer at Gilead Sciences Inc., the leading maker of HIV drugs, said the company might consider a small pilot trial but would like to see stronger evidence that the viruses cause CFS before launching a large trial. But "I'm very open and this would be a great opportunity,'' he said.

A spokesman for Merck & Co., another major manufacturer of HIV drugs said: "A clinical trial program would be possible to develop only after further substantial evidence of an association with CFS.''

Some doctors and patients are already testing the idea, based in part on a University of Utah and Emory University study in mice which suggested a cocktail of three anti-retroviral drugs appeared to inhibit infection by XMRV.

Jamie Deckoff-Jones, 56, a doctor and CFS patient in New Mexico, has been blogging about her experiences and those of her 20-year-old daughter. They both tested positive for XMRV and are taking a combination of three anti-retrovirals. Dr. Deckoff-Jones said a year ago she could only get up for short periods during the day. After five months on the drugs, she flew last week to Reno for an XMRV conference. Her daughter was able to go to a party and is enrolling in community college.

"This is all very new and there is no way to know if improvement will continue,'' Dr. Deckoff-Jones wrote in an email, "but we appear to be on an uphill course.''

Joseph Brewer, an infectious disease doctor in Kansas City, Mo., who treats AIDS patients, said he now has 15 patients with CFS in his clinic taking anti-retrovirals. "It's a mixed bag,'' said Dr. Brewer about the results. Patients who have been sick less than two years improve more rapidly, he said, adding that one of the challenges is that there is no reliable way to measure the amount of virus present in patients.

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