It's back to the drawing board for scientists seeking to find the cause of chronic fatigue syndrome (CFS), a disabling disorder that affects over a million Americans. Recent work by biologists in 2009 and 2010 indicated a potential link with two mouse-related viruses, XMRV and pMLV. And indeed, the early indications were promising, in that patients with these infections were exhibiting symptoms consistent with a chronic infection.
But just as the medical community was ready to celebrate this major achievement, a new study has appeared in mBio that has completely overturned the suspected links.
CFS, also called myalgic encephalomyelitis (ME), is a serious problem. It affects 1 in every 238 people and costs the United States upwards of $7 billion each year in medical expenses. And frustratingly, scientists haven't been able to find a cure — to a large extent, because they're not even sure what's causing it. And now, the new research coming from W. Ian Lipkin, Harvey Alter, and their team at the University of California has set them back even further.
The study was a classic case of performing scientific due diligence, while keeping fingers firmly crossed that the outcome would be a favorable one to medical science — namely the establishment of a firm link between CFS and the two mouse viruses, xenotropic murine leukemia virus-related virus (XMRV) and polytropic murine leukemia virus (pMLV).
And the study was a big deal — an initiative commissioned by the National Institute of Allergy and Infectious Diseases, and conducted under the auspices of the Center for Infection and Immunity at Columbia University's Mailman School of Public Health. The study also involved the Centers for Disease Control and Prevention, the Food and Drug Administration, and the NIH's National Cancer Institute and Warren G. Magnuson Clinical Center.
But all this effort, unfortunately, simply worked to disprove the connection between CFS and the viruses.
In the study, the researchers took a total of 239 subjects, of which 147 had CFS, and the remaining 146 being part of the control group. After ensuring that all the controls were met (e.g. no previous contact between test subjects, no prior history of neurological or psychiatric illness, etc.), the subjects were rigorously tested for evidence of any metabolic, endocrine, or infectious disease that might cause fatigue.
Once the tests were in, none of the labs found evidence of XMRV or pMLV in samples from the recruited CFS or control subjects. And just to make absolutely sure, the clinicians ran separate tests to make sure their equipment was operating properly.
Speaking through a release, lead author Dr. Judy Mikovits said she was disappointed that they found no association, but that "the silver lining is that our 2009 Science report resulted in global awareness of this crippling disease and has sparked new interest in CFS research."
The entire study can be read at mBio.
Image: Dmitriy Shironosov/Shutterstock.com.