Researchers recently investigated the role of the immune system in the chronic fatigue system in unprecedented depth. The findings could help design future treatments. A new study takes CFS from a new angle Chronic fatigue syndrome (CFS), or myalgic encephalomyelitis (ME), is a mysterious condition.
The main symptom of CFS is extreme and often relentless fatigue. Others include muscle and joint pain, trouble sleeping, and flu-like symptoms. Researchers don’t yet know what causes CFS. Suggestions include viral or bacterial infection, changes in the immune system, hormonal imbalance, and mental health conditions.
Because of this, they have not yet been able to design a test that can diagnose CFS, and current treatments only alleviate symptoms. Over the years, interest has grown in the role that the immune system might play in CFS. Often, people with CFS report that their symptoms began after an infection or other insult to the immune system. These reports are common, but once symptoms appear, it is impossible to assess how the body was behaving before arriving.
Researchers at the Institute of Psychiatry, Psychology and Neurosciences at King’s College London in the UK used an interesting model to dig deeper.
The researchers investigated people who were taking a treatment for hepatitis C called interferon alpha. Interferon-alpha works by activating the immune system in the same way that a significant infection would. People taking this course of medications often report CFS-like symptoms during treatment. A smaller number of people experience a CFS-like condition that can last for 6 months after treatment ends. Symptoms include fatigue, cognitive decline, and joint and muscle pain.
The scientists followed 55 people who underwent this treatment. They assessed his fatigue levels and measured immune markers before interferon-alpha treatment began. With this baseline information, they could monitor how each individual’s immune system reacted to interferon-alpha. Of the participants, 18 developed symptoms similar to CFS. The scientists have published their results in the journal Psychoneuroendocrinology.
Altered immune response
In those who experienced symptoms similar to CFS, the researchers observed an increased immune response to interferon alpha treatment. More specifically, this group produced roughly twice as much interleukin-10 and interleukin-6. Both molecules are important messengers of the immune system. Those who developed symptoms reported higher levels of fatigue during treatment, but did not report higher levels of fatigue before treatment.
Investigating immune markers, the scientists found that interleukin-10 levels were elevated in these people before interferon-alpha treatment began. They also showed an exaggerated response to interleukin-10 and interleukin-6 at the start of treatment.
There is still a lot to learn
Interestingly, once CFS-like illness developed, there were no longer detectable differences between the immune systems of those who developed the symptoms and those who did not. In another part of their study, the scientists compared the immune systems of 54 people with CFS to 57 people without CFS. Here, they found no significant differences in interleukin levels.
The researchers hope these findings may open up the future possibility of screening for people at increased risk of developing CFS. Of course, initially, it will be vital to replicate these results in people who develop CFS rather than a condition that reflects CFS. Because scientists don’t fully understand CFS yet, any information is crucial. The authors describe how they want to progress their understanding, saying:
“Future research should examine the molecular mechanisms underlying an exaggerated immune response and involved in the conversion of symptoms from acute to persistent fatigue.”