Serum from Myalgic encephalomyelitis/chronic fatigue syndrome patients causes loss of coherence in cellular circadian rhythms.
Wei, Heather, Adelsheim, Zoe, Fischer, Rita et al. · Journal of neuroimmunology · 2023 · DOI
Quick Summary
This study found that blood serum from ME/CFS patients disrupts the internal 24-hour biological clock (circadian rhythm) in cells grown in the laboratory, compared to serum from healthy people. The disruption was linked to how severe patients' sleep problems were. While a protein called TGF-beta contributed to some rhythm changes, it didn't fully explain the effect, suggesting other unknown factors in ME/CFS patients' blood are responsible.
Why It Matters
This research provides cellular-level evidence that ME/CFS patients have circadian rhythm disruption, potentially explaining the characteristic disrupted sleep, activity patterns, and daily symptom fluctuations. Identifying serum factors that damage circadian synchronization could lead to biomarkers for diagnosis and new therapeutic targets to restore normal daily rhythms.
Observed Findings
ME/CFS serum caused significant loss of circadian rhythm robustness in fibroblasts compared to control serum
ME/CFS serum nominally increased the rate of damping (weakening) of cellular rhythms
Damping rate was associated with insomnia severity measured by Pittsburgh Sleep Quality Index scores
TGF-beta1 levels were not significantly different between ME/CFS and control serum samples
Inferred Conclusions
Serum factors in ME/CFS patients disrupt cellular circadian synchronization, potentially contributing to the disrupted sleep and daily activity patterns characteristic of the illness
Multiple serum factors beyond TGF-beta1 are likely responsible for circadian disruption in ME/CFS
Insomnia severity in ME/CFS may be mechanistically linked to circadian damping at the cellular level
Remaining Questions
Which specific serum factors or proteins (other than TGF-beta1) cause circadian rhythm disruption in ME/CFS?
Do these circadian disruptions in fibroblasts translate to disrupted central (brain) and peripheral (body) circadian rhythms in living ME/CFS patients?
What This Study Does Not Prove
This study does not prove that circadian disruption is the primary cause of ME/CFS—it shows an association in cells exposed to patient serum. It does not identify which specific serum factors (other than TGF-beta) are responsible for the observed effects. Results in mouse fibroblasts may not directly translate to human physiology or explain all circadian disturbances in living ME/CFS patients.