E2 ModerateModerate confidencePEM unclearCase-ControlPeer-reviewedReviewed
Inflammatory and cell-mediated immune biomarkers in myalgic encephalomyelitis/chronic fatigue syndrome and depression: inflammatory markers are higher in myalgic encephalomyelitis/chronic fatigue syndrome than in depression.
Maes, Michael, Twisk, Frank N M, Ringel, Karl · Psychotherapy and psychosomatics · 2012 · DOI
Quick Summary
This study found that people with ME/CFS have higher levels of inflammatory markers (immune chemicals) in their blood compared to people with depression, even though both conditions can cause fatigue and other similar symptoms. The researchers measured specific immune proteins and found that while both ME/CFS and depression involve some immune system changes, ME/CFS shows a distinctly different immune profile that helps distinguish it from depression.
Why It Matters
This research provides biological evidence that ME/CFS involves a distinct inflammatory profile compared to depression, supporting the view that ME/CFS has biological underpinnings rather than being purely functional or psychological. This distinction is crucial for validating ME/CFS as a separate condition and may guide more targeted diagnostic and therapeutic approaches.
Observed Findings
- Plasma proinflammatory cytokines (IL-1 and TNF-α) were significantly higher in ME/CFS than in depression, and higher in both patient groups than in healthy controls.
- Serum neopterin (a cell-mediated immunity marker) was elevated in both ME/CFS and depression compared to controls, but did not differ significantly between the two patient groups.
- The positive correlations between neopterin and cytokines (IL-1 or TNF-α) were significantly stronger in depression than in ME/CFS, suggesting different immune communication patterns.
Inferred Conclusions
- ME/CFS and depression share a common 'pathway phenotype' involving inflammatory and cell-mediated immune dysfunction, which may explain why these conditions sometimes co-occur.
- ME/CFS is distinguished from depression by having distinctly higher proinflammatory cytokine levels and different immune cell communication networks.
- Inflammation likely contributes to the pathophysiology of both ME/CFS and depression, and elevated neopterin appears relevant to both conditions.
Remaining Questions
- Do the elevated inflammatory markers in ME/CFS patients precede symptom onset, or do they develop as a consequence of the disease process?
- What specific triggers or mechanisms cause the immune activation to differ between ME/CFS and depression?
- Are specific cytokine or neopterin thresholds useful for diagnostic purposes, and do these levels correlate with symptom severity or disease progression?
What This Study Does Not Prove
This study does not prove that inflammation causes ME/CFS, only that elevated inflammatory markers are associated with the condition. The cross-sectional design cannot establish whether immune changes precede symptom onset or result from the disease process. It also does not identify which specific triggers activate these inflammatory responses in ME/CFS patients.
Tags
Symptom:Fatigue
Biomarker:CytokinesBlood Biomarker
Method Flag:Weak Case DefinitionExploratory OnlySmall Sample
Metadata
- DOI
- 10.1159/000336803
- PMID
- 22832503
- Review status
- Editor reviewed
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 12 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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