E2 ModeratePreliminaryPEM unclearCase-ControlPeer-reviewedMachine draft
Not in the mind but in the cell: increased production of cyclo-oxygenase-2 and inducible NO synthase in chronic fatigue syndrome.
Maes, Michael, Mihaylova, Ivana, Kubera, Marta et al. · Neuro endocrinology letters · 2007
Quick Summary
This study found that people with ME/CFS have higher levels of two inflammatory molecules (COX-2 and iNOS) in their white blood cells compared to healthy people. The levels of these inflammatory markers were directly linked to how severe their symptoms were, including fatigue, pain, brain fog, and feeling like they have an infection. This suggests ME/CFS involves real inflammation in the body, not just psychological factors.
Why It Matters
This study provides biological evidence that ME/CFS involves measurable inflammatory abnormalities in immune cells, supporting the view that the condition has a physical, not purely psychological, basis. The findings suggest potential therapeutic targets through anti-inflammatory approaches and may help validate patients' experiences of genuine infection-like symptoms.
Observed Findings
- COX-2 and iNOS production by PBMCs was significantly higher in CFS patients than healthy controls.
- COX-2 and iNOS levels positively correlated with FibroFatigue scale severity scores.
- COX-2 and iNOS production correlated with specific symptoms: pain, muscular tension, fatigue, concentration difficulties, memory problems, sadness, and subjective infection.
- NFκB levels were significantly elevated in CFS patients and positively correlated with COX-2 and iNOS production.
Inferred Conclusions
- An intracellular inflammatory response in white blood cells plays an important role in ME/CFS pathophysiology.
- The transcription factor NFκB drives the inflammatory response observed in CFS.
- Symptoms like fatigue, pain, and cognitive defects reflect genuine inflammatory processes, not psychosomatic phenomena.
- COX-2 and iNOS inhibitors may be therapeutic candidates for treating ME/CFS.
Remaining Questions
- Is the elevated COX-2/iNOS production a primary driver of ME/CFS pathology or a secondary consequence of another underlying process?
- Do COX-2/iNOS levels change over time, and do they correlate with disease progression or remission?
What This Study Does Not Prove
This study does not prove that COX-2 and iNOS elevation causes ME/CFS; it only shows correlation. It cannot establish whether these inflammatory markers are primary drivers of disease or secondary consequences of other pathological processes. The small sample size and cross-sectional design limit generalizability and preclude causal inference.
Tags
Symptom:Cognitive DysfunctionPainFatigue
Biomarker:Gene ExpressionBlood Biomarker
Method Flag:Weak Case DefinitionSmall SampleExploratory Only
Metadata
- PMID
- 17693978
- 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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