Science / Medicine : Yuppie Flu Tied to Immune System

An overactive immune system is an important factor in causing chronic fatigue syndrome, often called the yuppie flu, California researchers said last week. The discovery, published in the Lancet, could mean that an invading infectious agent, possibly a virus, triggers a chain of immune responses that leave the victim feeling flu-like symptoms for six months or more.

Once the immune system is activated, it causes the body to pour out a stream of disease-fighting agents that help fight a virus but can lead to other debilitating illnesses. Jay A. Levy and his colleagues at UC San Francisco said the immune systems of six of the sickest patients in their study were activated for more than a year.

Symptoms of chronic fatigue syndrome include debilitating tiredness persisting for more than six months, low-grade fever, sore throat, swollen lymph glands, muscle and joint pains and sleep disorder. Doctors have theorized that it is caused by a virus. But no one viral agent has been consistently linked with the illness and the symptoms usually last some months longer than with a viral illness.

The California team said its study of 147 chronic fatigue patients found greater evidence of an activated immune system than in healthy people, people with other diseases or people recovering from acute viral illnesses. They said the activated immune system was most pronounced in patients with the most severe symptoms of chronic fatigue.