Immune System Changes Tied to Chronic Fatigue Syndrome

Chronic fatigue syndrome appears to be linked to specific changes in a person’s immune system, particularly increased amounts of chemical messengers that regulate immune responses, researchers report.

The study adds to growing evidence that chronic fatigue syndrome is caused by a malfunctioning immune system, said lead author Dr. Mady Hornig. She is director of Translational Research at the Jerome L. and Dawn Greene Infectious Disease Laboratory at Columbia University’s Mailman School of Public Health, in New York City.

The immune system of a new chronic fatigue syndrome patient appears unable to shut down or reduce its response to an infection that has passed, Hornig said.

Instead, the system continues to pump out large amounts of cytokines – chemical messengers that coordinate the response of the immune system’s may cell types. However, this only seems to occur during the first 3 years of the disease.

“Their immune system is no longer resilient and able to bounce back after this cytokine surge” in response to an infection, Hornig said. “We need the system to be regulated, so it shuts off after the disease is gone, and that isn’t happening here.”

Doctors now can look for increased levels of these chemicals in the blood of patients who might have chronic fatigue syndrome, potentially aiding in their diagnosis, she said.

The new study, published February 27 in the journal Science Advances, comes on the heels of a new Institute of Medicine (IOM) report that declared chronic fatigue syndrome a “legitimate” illness that should be treated by doctors as a disease rather than an emotional problem.

Between 836,000 and 2.5 million Americans suffer from chronic fatigue syndrome, and an estimated 84 to 91% of people with the disorder are not diagnosed, according to the IOM. Chronic fatigue syndrome tends to strike people in their 40s and 50s, and occurs four times more often in women than men.