Virus link found to chronic fatigue

In what may prove to be the first major breakthrough in the fight against the mysterious disorder known as “chronic fatigue syndrome” (CFS), researchers reported Thursday that they have found traces of a virus in the majority of patients with the disease.

The same virus has previously been identified in at least a quarter of prostate tumors, particularly those that are very aggressive, and has also been linked to certain types of cancers of the blood.

It remains possible that the virus, known as xenotropic murine leukemia virus-related virus, or XMVR, is a passenger virus that infects patients whose immune systems have been suppressed by other causes.

But the new findings were sufficiently alarming that the National Cancer Institute called together a group of experts in August to consider its potential effect on public health.

“We are in the very early days,” said Stuart LeGrice, director of the National Cancer Institute’s Center of Excellence in HIV/AIDS and Cancer Virology, who organized the meeting but was not involved in the new study. “The data need to be confirmed and repeated.”

Chronic fatigue syndrome, which affects at least 1 million Americans and more than 17 million people worldwide, is characterized by debilitating fatigue, chronic pain and depression, as well as other symptoms.

Many doctors have argued that it is not a real disorder because there have previously been no biochemical markers that characterize it. The only effective treatments are behavioral changes and antidepressants, and they are of limited benefit.

CFS has been theoretically linked to a variety of other viruses, including Epstein-Barr virus and human herpesvirus-6, but none have been found in a significant proportion of patients.

Thursday’s findings could explain why. Like HIV, which causes a constellation of symptoms, XMRV is a retrovirus, and retroviruses are known to suppress the immune system, making it easier for other viruses to establish themselves in a human body.

The new study was organized by Judy A. Mikovits, director of research at the Whittemore Peterson Institute, a CFS-oriented facility on the campus of the University of Nevada, Reno.