E2 ModeratePreliminaryPEM unclearCase-ControlPeer-reviewedMachine draft
Plasma cytokines in women with chronic fatigue syndrome.
Fletcher, Mary Ann, Zeng, Xiao Rong, Barnes, Zachary et al. · Journal of translational medicine · 2009 · DOI
Quick Summary
Researchers tested blood samples from women with ME/CFS and compared them to healthy women to look for immune system differences. They measured 16 different immune substances called cytokines and found that 10 of them were abnormal in ME/CFS patients—some were higher and some were lower than in healthy controls. While these differences suggest immune activation in ME/CFS, the pattern wasn't specific enough to use as a diagnostic test on its own.
Why It Matters
This study addresses the critical need for objective biomarkers in ME/CFS diagnosis and prognosis by systematically measuring a large cytokine panel with modern multiplex technology. The identification of specific cytokine abnormalities, particularly IL-5 and LTα, provides potential targets for therapeutic intervention and demonstrates feasibility of immune profiling as a diagnostic approach.
Observed Findings
- Seven cytokines were elevated in ME/CFS: lymphotoxin-alpha, IL-1α, IL-1β, IL-4, IL-5, IL-6, and IL-12.
- Three cytokines were decreased in ME/CFS: IL-8, IL-13, and IL-15.
- IL-5 showed the strongest biomarker potential with area under the ROC curve of 0.84; LTα, IL-4, and IL-12 also showed good discrimination (AUC 0.76–0.77).
- Six cytokines showed no significant difference between ME/CFS patients and controls: TNFα, IFNγ, IL-2, IL-10, IL-23, and IL-17.
Inferred Conclusions
- Cytokine abnormalities are common in ME/CFS and suggest immune activation and inflammatory dysregulation.
- Multiple cytokines (10 of 16) demonstrate good to fair potential as biomarkers, with IL-5, LTα, IL-4, and IL-12 showing the most promise.
- The observed cytokine profile reflects non-specific immune activation rather than a disease-specific signature, but these abnormalities represent potential therapeutic targets.
- Multiplex cytokine measurement is a feasible, cost-effective approach for evaluating immune dysfunction in ME/CFS.
Remaining Questions
- Can these cytokine biomarkers be validated in an independent cohort, and do they correlate with symptom severity or disease progression?
- Are cytokine patterns consistent across different ME/CFS subtypes or do they vary by disease duration and stage?
What This Study Does Not Prove
This study does not establish whether cytokine abnormalities cause ME/CFS symptoms, are merely associated with the disease, or represent secondary effects of prolonged immune activation and inflammation. The study also does not demonstrate that any single cytokine is specific enough for clinical diagnosis, nor does it clarify whether cytokine patterns differ across ME/CFS subtypes or disease stages.
Tags
Symptom:Fatigue
Biomarker:CytokinesBlood Biomarker
Method Flag:Weak Case DefinitionSmall SampleExploratory Only
Metadata
- DOI
- 10.1186/1479-5876-7-96
- PMID
- 19909538
- Review status
- Machine draft
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 8 April 2026
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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