Chronic fatigue syndrome’s headaches, muscle aches, tiredness, and concentration problems have no known cause, so a paper published online yesterday, in which researchers report finding a type of virus in 87 percent of 37 chronic fatigue syndrome (CFS) patients tested, seems a promising step. But in statements to the media the researchers stress caution in interpreting results. The group also noted that it had delayed publishing the paper, originally meant to appear in the Proceedings of the National Academy of Sciences in May, due to conflicting reports from other scientists.
The National Institutes of Health’s Dr. Harvey Alter, senior author of the paper, said in a conference call with reporters, “It’s an association, but that’s all it is.” He was careful to say the findings don’t prove that a virus causes CFS. [NPR]
Alter’s caution is understandable, especially given recent CFS research history:
October 2009: A virus, XMRV (xenotropic murine leukemia virus–related virus), is found in 68 of 101 CFS patients.
January 2010: XMRV is not found in a British study that tested CFS patients.
July 2010: XMRV is not found in a Center for Disease Control study testing CFS patients.
Though this new study did not find XMRV (a virus also associated with prostate cancer), it found other viruses in the MLV (murine leukemia virus-related viruses) family–viruses not found in July’s Center for Disease Control study. That conflicting study was the reason for the publication’s delay, despite clamoring from some chronic fatigue syndrome patients.
“My colleagues and I are conducting additional experiments to ensure that the data are accurate and complete,” wrote co-author Harvey Alter of the National Institutes of Health, in an email statement to The New York Times last month. “Our goal is not speed, but scientific accuracy,” he wrote. [Scientific American]
As Scientific American reports, some researchers believe that the previous studies’ contradictions may be explained by the variety of patients chosen for the different studies (some much sicker than others), and perhaps the existence of different causes in different geographical regions. But in a commentary (pdf) published along with Alter’s study, a group of researchers led by Valerie Courgnaud called a geographic explanation “baffling.”
Given the syndrome’s confusing past, some researchers now hope to take a different tack: Another way to see if viruses are to blame, they say, is to monitor how chronic fatigue syndrome patients respond to anti-retroviral drugs.
Andrew Mason, a University of Alberta professor, co-wrote the commentary in the journal 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. [Wall Street Journal]
Pharmaceutical companies such as Merck & Co. and Gilead Sciences Inc. say more research is needed before they start large clinical trials, The Wall Street Journal reports, but others are already trying antiviral treatments on a small scale. A New Mexico doctor and blogger, Jamie Deckoff-Jones, and her 20-year-old daughter started taking a combination of three anti-retrovirals after being diagnosed with XMRV.
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Image: Whittemore Peterson Institute