Are you always feeling extremely tired, for no apparent reason? Scientists might have figured out why — it’s something to do with your cytokines.

Sufferers of chronic fatigue syndrome experience tiredness and unrefreshing sleep. Image via Wikipedia.

Neverending fatigue

Chronic fatigue syndrome (CFS) is a medical condition characterized by unexplainable long-term fatigue, as well as muscle or joint pain, headaches, and other flu-like symptoms. Medics have proposed several mechanisms, but so far, we don’t really know what’s causing it or what the underlying mechanism is. We also don’t really know how common this problem is. Estimates of the number of persons with the condition vary from 7 to 3,000 per 100,000 adults. It’s estimated that in the US, 836,000 to 2.5 million people suffer from the condition. A new study might finally shed some light on this mysterious — and often trivialized — condition.

“Chronic fatigue syndrome can turn a life of productive activity into one of dependency and desolation,” Jose Montoya, M.D., lead author of the new study, published Monday in the Proceedings of the National Academy of Sciences, said in a statement.

He and his collaborators found that people suffering from the syndrome had substantially higher levels of substances called cytokines in their blood. Cytokines are a broad category of small proteins important in cell signaling. They share similarities to hormones, and there’s still an ongoing debate regarding whether the two groups are separate or not. Cytokines also play a role in immune responses to infection and inflammation.

Cytoines been discussed as connected to CFS before, but no theory managed to prevail until now. In past decades, many even believed CFS to be a fictitious condition. Though it has gained some acceptance in recent times, there’s still a shroud of controversy around CFS.

“This is a field that has been full of skepticism and misconception, where patients have been viewed to have invented their disease. These data clearly show the contrary, and demonstrate what can be achieved when we couple good research design with new technology,” Montoya, professor of infectious diseases at Stanford, tells NPR Shots.

Hopefully, this study will help clear the water.

No-rest Cytokines

Montoya and colleagues found levels of 17 cytokines dramatically higher than normal in patients suffering from CFS. Out of these 17, no less than 13 were associated with promoting inflammation. This is highly significant and fits with previous studies that found inflammation and CFS to be connected.

The study has also been well received by other researchers. Dr. Anthony L. Komaroff, a Harvard internist and epidemiologist who has written a commentary to accompany the study, believes this work finally shows that cytokines are what’s causing the symptoms — but there’s a catch.

Previous studies also tried to prove the same thing, but they came out negative. Montoya says that this was happening because the lab tests simply weren’t measuring the right thing. Most commonly, two tests are carried out: the first is sedimentation rate, which is the ability of red blood cells to clump together. This isn’t relevant for CFS. The second is C-reactive protein, which is indicative of cytokine, but only of a single cytokine, and not one that scientists identified in this study. Basically, these are imperfect measures that oversimplify and distort our image of inflammation. We need new tests, new measures, and then we will be able to improve our understanding of complex issues such as chronic fatigue syndrome. While scientific ways to measure the relevant values exist, they need to be translated into an efficient, commercial setting, before they can become widespread.

“There is much to learn,” Komaroff writes, in the journal. “Hopefully, a decade from now, “doctors will know better what to measure and, more importantly, what to do to ease the suffering caused by this illness.”

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