Chronic Fatigue Syndrome: The Current Status and Future Potentials of Emerging Biomarkers

Abstract

Chronic fatigue syndrome (CFS) remains an incompletely characterized illness, in part due to controversy regarding its definition, biological basis and diagnosis. Biomarkers are objective measures that may lead to improvements in our understanding of CFS by providing a more coherent and consistent approach to study, diagnosis and treatment of the illness. Such metrics may allow us to distinguish between CFS subtypes – each defined by characteristic biomarkers – currently conflated under the single, heterogeneous condition of CFS. Here, we review potential CFS biomarkers related to neurological and immunological components of the illness, and discuss how these biomarkers may be used to move the field of CFS forward, emphasizing clinical utility and potential routes of future research. We reviewed recent research in CFS, and identified the findings that could be applied as biomarkers in the diagnosis of CFS. We grouped these potential biomarkers according to the subtypes of CFS in which they might be positive. We found several studies that have discovered discrete and measurable differences in CFS patients, ranging from scores on neuropsychological testing to cytokine profiles. The studies discussed have the potential to contribute to the objective characterization of CFS through their utility as biomarkers. As such, they do not merely improve the diagnosis of CFS, but may help to identify distinct subtypes of CFS characterized by unique sets of biomarkers. These clinical delineations, in turn, may guide more granular, focused, and targeted treatment strategies based on more precise characterizations of the illness.