From the Wall Street Journal, 18 Septemnber (story by Amy Dockser Marcus).
The saga of the retrovirus XMRV and chronic fatigue syndrome appears to have ended, now that researchers in a federally funded study said they found no relationship between the retrovirus and the illness.
The controversy dates back to 2009, when a paper in the journal Science found a possible connection between chronic fatigue syndrome and XMRV. A retrovirus is a kind of virus that copies its own genes into a host's DNA.
There is no known cause or cure of chronic fatigue syndrome, a condition characterized by symptoms that include memory and concentration problems, severe fatigue and muscle or joint pain. The Centers for Disease Control and Prevention estimates that more than a million Americans have chronic fatigue syndrome, which is also known as myalgic encephalomyelitis.
The 2009 paper created excitement that the finding might lead to therapies for chronic fatigue syndrome. CFS patients, who say their condition often isn't taken seriously by doctors, hoped the research, which suggested a viral cause, would help validate the disease.
In a paper published Tuesday in the journal mBio, scientists said they found no evidence of infection in the blood of 293 people, including those with the condition and healthy controls. Authors of the latest research include some of those involved in previous studies that linked the mouse retrovirus XMRV, and a second mouse retrovirus known as pMLV, to chronic fatigue syndrome.
To many in the scientific community, the results out Tuesday were widely expected. In December, Science retracted the 2009 paper that set off the controversy, citing the failure of numerous laboratories to replicate the findings.
The scientific consensus now is that the original finding was due to lab contamination, possibly of mouse DNA in samples of patients participating in the study.
But W. Ian Lipkin, principal investigator of Tuesday's National Institutes of Health-funded study and director of the Center for Infection and Immunity at Columbia University's Mailman School of Public Health, said that while many scientists felt the question had been settled, “it was not settled in the [chronic fatigue syndrome] community.”
“To really convincingly demonstrate there is or isn't an association between an agent and disease, you have to allow the people who did the report to test whatever they reported in blinded fashion. We have done that now,” Dr. Lipkin said.
The initial finding sparked concerns about the safety of the nation's blood supply, because many samples of healthy controls in the Science study also were found to be infected with XMRV. The American Red Cross barred people with CFS from donating blood, a ban that remains in effect but may be reconsidered in the future, said Susan L. Stramer, the organization's executive scientific officer.
In the NIH-funded study, patients with chronic fatigue syndrome were identified at six different sites around the country by doctors who used agreed-upon criteria. Healthy controls were matched with the patients by age, sex, race, and geographic region, and their blood was drawn at the same time of day and during the same season.
Judy Mikovits, who led the 2009 XMRV study and is an author of the mBio paper, said that although the recent effort found no association of the viruses with chronic fatigue syndrome, it helped develop a collection of CFS samples never before available to investigators, which would advance study of the disease.
Researchers and patients said the XMRV saga brought new attention to the disorder. Dr. Lipkin is part of a multimillion-dollar privately funded effort searching for causes of CFS.
Robert Miller of Reno, Nev., a CFS patient and patient advocate, said the controversy drove a group of patients to contact the U.S. Food and Drug Administration to discuss how to advance drug development. Last week, the FDA held a call in which officials acknowledged the severity of the disease and the need for treatments and laid out steps it is taking to move research forward.
“XMRV has faded away,” Mr. Miller said. “The illness has not.”
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