(If only they would say ME, Myalgic Encephalomyelitis, instead of CFS)
By Andy Coghlan
Inflammation biomarkers may help doctors diagnose chronic fatigue syndrome (CFS), a poorly-understood condition in which people feeling continually exhausted. These biomarkers could also give new clues to what causes the condition, and how to treat it.
The biomarkers were discovered when a team of researchers screened the blood of 192 people with chronic fatigue syndrome for cytokines – substances used by the immune system to control inflammation. The team compared the levels of 51 different cytokines in the people with CFS and 392 people who didn’t have the condition, and found that 17 cytokines rose in tandem with how bad a person’s CFS was.
“These 17 go up by various degrees in a straight line with severity,” says José Montoya, of Stanford University.
Overall, only one cytokine was consistently higher in people with CFS. But when severity was taken into account, the other 16 emerged from the analysis as being linked to the condition. For example, three-times as much of the appetite hormone leptin, which is part of the cytokine family, was present in people with very bad cases of CFS.
It is not yet clear whether the increase in inflammation markers could be a cause or result of the condition.
However, Montoya says the results support mounting evidence that CFS is a physiological condition, not a psychosomatic disorder. “There’s no question this is something that’s biologically based,” he says. “This is a disease that does not get cured with psychological treatments, counselling or anti-depression drugs.”
Montoya’s team want to use the biomarkers to develop ways to diagnose CFS, also known as myalgic encephomyelitis, and monitor its severity. These cytokines may also help identify new CFS treatments that dampen inflammation, Montoya says.
“The results and how they were obtained are encouraging, as finding markers for subsets and categorisations within the illness is much needed for future research and treatments,” says Chris Armstrong, of the University of Melbourne, Australia.
Armstrong’s own team have found that the fatigue of CFS may be caused by disrupted metabolism and energy production in the body. “The metabolic changes we found suggest a physiological stressor in the body is affecting the cells,” he says. “The cause of that stress is unknown, but is likely to be immune-based given the mounting evidence in that direction – this new study included.”
A team in Norway has had some early success in treating CFS by targeting the immune system and reducing inflammation. They have been using a drug called rituximab to wipe out the white blood cells that may make inflammatory antibodies.
Montoya says it’s unclear what causes the increase in cytokines they have seen in CFS, but he thinks something is triggering inflammation in the body – possibly an infection like the herpes virus.
Journal reference: PNAS, DOI: 10.1073/pnas.1710519114