Researchers Say They’ve Created a Blood Test for Chronic Fatigue Syndrome

Image: Esther Max (Flickr (CC-BY-SA 2.0))

Researchers at Stanford University and elsewhere say they’ve taken an important step in potentially helping people with a barely understood ailment that’s long been viewed skeptically by the public and even some doctors. They claim to have created a blood test that may be able to readily identify people who have myalgic encephalomyelitis, also known as chronic fatigue syndrome (ME/CFS).

The diagnostic test not only further validates a biological basis for sufferers’ symptoms, the authors say, but may point to new avenues of treatment for the often unmanageable condition.

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Currently, ME/CFS is a diagnostic label we give to people who experience prolonged, crippling fatigue—especially after exercising—and other symptoms like chronic pain, that can’t be explained by any other known illness. The elusiveness of ME/CFS once led many doctors to consider it a psychological ailment, with people’s symptoms blamed on a psychosomatic manifestation of their stress or anxiety. But in recent years, the medical community has by and large accepted that the symptoms of ME/CFS have a physical root, even if we still don’t know how it happens.

One major stumble in understanding the disorder is the lack of biomarkers that doctors could use to identify it in patients—people with ME/CFS tend to have levels of immune cells or other markers of health that are indistinguishable from the average person. It’s estimated that as many as 2 million in the U.S. may have ME/CFS, according to the Centers for Disease Control and Prevention, but more than 90 percent are not diagnosed. Those who are diagnosed have to go through an exhausting, frustrating battery of tests that rule out other illnesses, and often have few or no ways to even manage their symptoms.

But the researchers behind this current study, published Monday in the Proceedings of the National Academy of Sciences, say they’ve devised a test that, at least in a small sample of people, can tell apart people with ME/CFS from the general population.

Their test, a “nanoelectronics blood-based assay,” measures how a person’s immune cells and blood plasma interfere with an electrical current, then uses those results as a proxy for the cells’ overall health (the greater the change in current, essentially, the less healthy the cells). In this case, they were hoping to see how these cells respond to stress, so they exposed them to salt, since it forces them to compensate for osmosis, or the moving of water from inside the cell. Then they had the cells run through the current.

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In their pilot study, they tested blood samples from 40 people. Half had been diagnosed with ME/CFS, while the other half were healthy volunteers. And in all the samples from the ME/CFS patients, they could detect relatively big changes in current compared to those from healthy people.

“We don’t know exactly why the cells and plasma are acting this way, or even what they’re doing,” said senior author Ron Davis, a biochemist and geneticist at Stanford University, in a statement. “But there is scientific evidence that this disease is not a fabrication of a patient’s mind. We clearly see a difference in the way healthy and chronic fatigue syndrome immune cells process stress.”

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The team’s test could theoretically not only be used to diagnose ME/CFS in people, but also track the effectiveness of potential future treatments, and whether they can restore the cells’ stress response back to normal. Many of these treatments are already being explored for ME/CFS, but the team was also able to find a drug that seems to help ME/CFS-affected cells better respond to stress but isn’t currently being tested out. The tiny components used to create the tests are also relatively inexpensive, making it that much easier to someday mass-produce them and make them accessible to doctors and patients.

But there’s still a long way to go before their test should be considered a slam dunk, with many questions left unanswered. Researchers elsewhere have made early efforts to find potential biomarkers for ME/CFS, for instance, but these biomarkers are unlikely to help doctors diagnose every case. That’s not entirely surprising since there’s no single cause or underlying mechanism that will explain every individual’s symptoms (among the possible factors are viral infections, genetics, and thyroid problems). So while the team’s test may have identified everyone with ME/CFS in their sample, that doesn’t mean the same will be true once they start studying larger groups of people.

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Still, for people with ME/CFS (including Davis’ own son, whose diagnosis inspired him to begin studying the illness), these incremental advances are worth their weight in gold.

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About the author

Ed Cara

Science writer at Gizmodo and pug aficionado elsewhere