Virus Seen in Muscle from Chronic Fatigue Patients

By Will Boggs, MD

NEW YORK (Reuters Health) - A persistent enterovirus infection in muscles
may be to blame for some cases of chronic fatigue syndrome (sometimes called
fibromyalgia) and others with chronic inflammatory muscle disease, a French
team reports.

They detected genetic material (specifically RNA) from enteroviruses in 20
percent of muscle biopsies from patients with chronic inflammatory muscle
diseases and 13 percent of patients with fibromyalgia/chronic fatigue
syndrome, but not from healthy volunteers.

The findings favor a persistent infection involving defective viral
replication as a cause of these conditions.

"The persistence of defective or infectious enteroviruses is well
established for a lot of organs," Dr. Bruno Pozzetto from the University
Hospital Center of Saint-Etienne, France, told Reuters Health.

Such infections have been documented in the heart, with possible involvement
in heart enlargement; in pancreatic cells, possibly linked to juvenile
diabetes; and in the central nervous system in association with a syndrome
that afflicts aging survivors of polio, the researcher explained. "However,
the link between these diseases, as well as chronic inflammatory muscle
diseases, and viral persistence is not clear."

Pozzetto and colleagues investigated the presence of enterovirus in skeletal
muscle biopsies from 15 patients with chronic inflammatory muscle diseases,
30 patients with fibromyalgia/chronic fatigue syndrome, and 29 healthy
subjects to test their hypothesis that skeletal muscle may play host to
persistent enteroviral infection.

Three patients with chronic inflammatory muscle disease and four patients
with fibromyalgia/chronic fatigue syndrome were positive for enterovirus
RNA, the team reports in the Journal of Medical Virology.

None of the muscle biopsies in this study contained a particular viral
protein, the researchers note, which "suggests a defective viral
replication."

It is too early to derive implications for treatment from these results,
Pozzetto said.

However, he noted that so-called Coxsackie B viruses seem to play a key role
in persistent muscular infections. "To prevent this persistence, an
inactivated vaccine directed toward these viruses could be indicated."

Also, an antiviral agent called pleconaril, "acting during the early phases
of the viral cycle, could also be useful in muscular diseases clearly
associated with enterovirus." This is being tried in some cases of
heart-muscle enlargement, Pozzetto said, but "it is too early to answer for
muscular diseases."

SOURCE: Journal of Medical Virology, December 2003.


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