ABOVE: A diagnostic device for ME/CFS that measures changes in electrical impedance in blood cells

R. ESFANDYARPOUR

A distinguishing characteristic of the disease myalgic encephalomyelitis/chronic fatigue syndrome appears to be the electrical response of patients’ blood cells when under stress, researchers report today (April 29) in PNAS. The team hopes the finding will speed diagnoses for people with the condition and facilitate research on it.

The University of California, San Diego’s Robert Naviaux, a genetics professor who was not involved in the research, tells the San Francisco Chronicle, “It’s a major milestone. If it holds up in larger numbers, this could be a transformative advance.”

Up to 2.5 million Americans are thought to have myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), whose symptoms can include severe fatigue that isn’t explained by exertion, pain, and difficulties concentrating or remembering. It is currently diagnosed based on symptoms, as no biomarker for it exists.

To see whether the blood cells of ME/CFS patients respond differently to stress than those of healthy people, researchers exposed cells from a patient’s blood sample to salt to stress them, then ran them through a device that measures electrical impedance—a proxy for energy use. After the test picked up differences between the patient’s blood and that of healthy people, the research team used the test to compare blood cells from 20 patients with ME/CFS and 20 healthy people, and found that it reliably distinguished members of the two groups.

“We don’t know exactly why the cells and plasma are acting this way, or even what they’re doing. But there is scientific evidence that this disease is not a fabrication of a patient’s mind,” Ron Davis, a biochemist at Stanford University who began studying ME/CFS after his son became bedridden with the disease, tells The Sacramento Bee. “We clearly see a difference in the way healthy and chronic fatigue syndrome immune cells process stress.”

Research on ME/CFS has been controversial, with scientists who test talk therapy and exercise for the condition facing harassment from activists who see such treatments as harmful and rooted in a mistaken idea that the illness is psychological, according to a report last month in Reuters. Davis tells the San Francisco Chronicle that he hopes the discovery of a biomarker “will help the medical community accept that this is a real disease.”

Simon Wessely, a psychiatrist at King’s College London’s Institute of Psychiatry, Psychology & Neuroscience who works with ME/CFS patients, writes in an email to Reuters that the study was unable to solve two key issues: “The (first) issue is, can any biomarker distinguish CFS patients from those with other fatiguing illnesses? And second, is it measuring the cause, and not the consequence, of illness?”