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Valganciclovir for chronic fatigue syndrome to be tested


A preliminary study suggests there may be hope in the offing for some sufferers of chronic fatigue syndrome ( CSF ) with a new therapy being tested by researchers at the Stanford University School of Medicine.

José Montoya and Andreas Kogelnik have used the drug Valganciclovir ( Valcyte ) - an antiviral often used in treating diseases caused by human herpes viruses - to treat a small number of chronic fatigue syndrome patients.

The researchers said they treated 25 patients during the last three years, 21 of whom responded with significant improvement that was sustained even after going off the medication at the end of the treatment regimen, which usually lasts six months. The first patient has now been off the drug for almost three years and has had no relapses.

" This study is small and preliminary, but potentially very important," said Anthony Komaroff, at Harvard Medical School, who was not involved in the study. " If a randomized trial confirmed the value of this therapy for patients like the ones studied here, it would be an important landmark in the treatment of this illness."

Chronic fatigue syndrome has baffled doctors and researchers for decades, because aside from debilitating fatigue, it lacks consistent symptoms. Although many genetic, infectious, psychiatric and environmental factors have been proposed as possible causes, none has been nailed down. It was often derided as "yuppie flu," since it seemed to occur frequently in young professionals, though the Centers for Disease Control and Prevention ( CDC ) says it's most common in the middle-aged. But to those suffering from it, CFS is all too real and its effects are devastating, reducing once-vigorous individuals to the ranks of the bedridden, with an all-encompassing, painful and sleep-depriving fatigue.

More than 1 million Americans suffer from the disorder, according to the CDC. The disease often begins with what appears to be routine flulike symptoms, but then fails to subside completely - resulting in chronic, waxing and waning debilitation for years.

Valganciclovir is normally used against diseases caused by viruses in the herpes family, including cytomegalovirus, Epstein-Barr virus and human herpes virus-6. These diseases usually affect patients whose immune systems are severely weakened, such as transplant and cancer patients. Montoya, who had used the drug in treating such patients for years, decided to try using it on a CFS patient who came to him in early 2004 with extremely high levels of antibodies for three of the herpes family viruses in her blood. At the time, she had been suffering from CFS for five years.

When a virus infects someone, the levels of antibodies cranked out by the immune system in response typically increase until the virus is overcome, then slowly diminish over time. But Montoya's patient had persistently high antibodies for the three viruses. In addition, the lymph nodes in her neck were significantly enlarged, some up to eight times their normal size, suggesting her immune system was fighting some kind of infection, even though a comprehensive evaluation had failed to point to any infectious cause.

Concerned about the unusual elevations in antibody levels as well as the swelling of her lymph nodes, Montoya decided to prescribe Valganciclovir. " I thought by giving an antiviral that was effective against herpes viruses for a relatively long period of time, perhaps we could impact somehow the inflammation that she had in her lymph nodes," said Montoya.

Within four weeks, the patient's lymph nodes began shrinking. Six weeks later she phoned Montoya from her home in South America, describing how she was now exercising, bicycling and going back to work at the company she ran before her illness. "We were really shocked by this," recalled Montoya.

Of the two dozen patients Montoya and Kogelnik have since treated, the 20 that responded all had developed CFS after an initial flulike illness, while the non-responders had suffered no initial flu.

Montoya and Kogelnik emphasized that even if their new clinical trial validates the use of Valganciclovir in treating some CFS patients, the drug may not be effective in all cases. In fact, the trial will assess the effectiveness of the medication among a specific subset of CFS patients; namely, those who have viral-induced dysfunction of the central nervous system.

" This could be a solution for a subset of patients, but that subset could be quite large, " said Kristin Loomis, executive director of the HHV-6 Foundation, which has helped fund a significant portion of the preparatory work for the clinical trial. " These viruses have been suspected in CFS for decades, but researchers couldn't prove it because they are so difficult to detect in the blood. If Montoya's results are confirmed, he will have made a real breakthrough. "

Source: Stanford University Medical Center, 2007


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