C-reactive protein (CRP) is a protein produced by the liver that is often used as a marker of systemic inflammation. Elevated levels of CRP have been associated with a variety of inflammatory and infectious conditions, including ME/CFS.
Several studies have found that ME/CFS patients have higher levels of CRP compared to healthy controls. For example:
- A 2015 study published in the journal Clinical Therapeutics found that ME/CFS patients had significantly higher levels of CRP compared to healthy controls.
- A 2019 study published in the Journal of Translational Medicine found that ME/CFS patients had significantly higher levels of CRP compared to healthy controls, and that CRP levels were positively correlated with disease severity.
- A 2020 study published in the journal Brain, Behavior, and Immunity found that ME/CFS patients had significantly higher levels of CRP compared to healthy controls, and that CRP levels were associated with cognitive impairment and severity of symptoms.
While the exact role of CRP in ME/CFS is not yet fully understood, it is thought that elevated levels of CRP may be a marker of chronic inflammation in these patients. Additionally, elevated CRP levels could be contributing to some of the symptoms experienced by ME/CFS patients, such as fatigue and pain.
It is important to note, however, that not all ME/CFS patients have elevated levels of CRP, and that CRP levels can be elevated for a variety of reasons. Therefore, CRP levels alone are not a definitive diagnostic marker for ME/CFS, and should be considered in conjunction with other clinical findings.