Chronic Fatigue Syndrome (CFS), a mysterious and debilitating exhaustion that is not relieved by sleep, appears to be linked to a retrovirus, researchers announced Thursday in a breakthrough study.
In the latest issue of Science, researchers said their findings could lead to a treatment for an ailment affecting millions of Americans and that in some cases render them unable to work or engage in even moderately robust activities.
The study was hailed as a breakthrough in understanding the perplexing syndrome for which there is no known treatment.
"We now have evidence that a retrovirus named XMRV is frequently present in the blood of patients with CFS," said Judy Mikovits, director of research for the Whittemore Peterson Institute (WPI) located at the University of Nevada, Reno, one of the organizations which led the research.
"This discovery could be a major step in the discovery of vital treatment options for millions of patients," Mikovits said.
Other health agencies which contributed to the study were the National Cancer Institute (NCI), the National Institutes of Health, and the Cleveland Clinic.
Researchers cautioned that while there appears to be a relationship between the retrovirus and Chronic Fatigue Syndrome, they have not proven that the illness is caused by XMRV.
They noted that earlier research has linked the retrovirus with prostate cancer as well.
"The discovery of XMRV in two major diseases, prostate cancer and now chronic fatigue syndrome, is very exciting," said Robert Silverman, a professor in the Department of Cancer Biology at the Cleveland Clinic Lerner Research Institute, and co-author of the CFS study.
"If cause-and-effect is established, there would be a new opportunity for prevention and treatment of these diseases," he said.
In the study released Thursday, WPI scientists identified XMRV in the blood of 68 of 101 (67 percent) CFS patients.
By contrast, the retrovirus was found in the blood of only eight of 218 healthy people (3.7 percent).
"These compelling data allow the development of a hypothesis concerning a cause of this complex and misunderstood disease, since retroviruses are a known cause of neurodegenerative diseases and cancer in man," said Francis Ruscetti, of the Laboratory of Experimental Immunology at NCI.
Retroviruses like XMRV have also been shown to activate a number of other latent viruses. This could explain why so many different viruses, such as Epstein-Barr virus have been associated with CFS.
"The scientific evidence that a retrovirus is implicated in CFS opens a new world of possibilities for so many people," said Annette Whittemore, founder and president of WPI and mother of a CFS patient.
"Scientists can now begin the important work of translating this discovery into medical care for individuals with XMRV related diseases."