E2 ModeratePreliminaryPEM unclearCross-SectionalPeer-reviewedReviewed
Increased plasma peroxides as a marker of oxidative stress in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
Maes, Michael, Kubera, Marta, Uytterhoeven, Marc et al. · Medical science monitor : international medical journal of experimental and clinical research · 2011 · DOI
Quick Summary
This study measured two markers of oxidative stress (damage caused by harmful molecules in the body) in people with ME/CFS compared to healthy people. Researchers found that ME/CFS patients had significantly higher levels of plasma peroxides—harmful molecules that damage cells. These findings suggest that oxidative stress may play a role in ME/CFS, which could help explain some of the illness's symptoms.
Why It Matters
Identifying objective biomarkers like elevated plasma peroxides could improve ME/CFS diagnosis and help validate the biological basis of the illness. Understanding that oxidative stress is increased in ME/CFS may point toward potential therapeutic targets and support the recognition of ME/CFS as an organic disease rather than purely psychological.
Observed Findings
- Plasma peroxide concentrations were significantly higher in ME/CFS patients compared to healthy controls.
- Serum oxLDL antibody levels showed a trend toward elevation in ME/CFS patients, though this did not reach full statistical significance.
- Both biomarkers (plasma peroxides and oxLDL antibodies) contributed significantly to distinguishing ME/CFS patients from normal controls.
- Plasma peroxide and serum oxLDL antibody levels were significantly correlated with at least one symptom on the Fibromyalgia and Chronic Fatigue Syndrome Rating Scale.
Inferred Conclusions
- ME/CFS is characterized by increased oxidative stress, as demonstrated by elevated plasma peroxide levels.
- Oxidative stress markers may serve as objective biomarkers for ME/CFS diagnosis and severity assessment.
- Oxidative and nitrosative stress pathways are activated in ME/CFS, supporting the broader immune and inflammatory dysfunction model of the disease.
Remaining Questions
- Do oxidative stress levels change over the course of ME/CFS illness, or are they stable baseline markers?
- What causes the increased oxidative stress in ME/CFS—is it from immune activation, mitochondrial dysfunction, reduced antioxidant defenses, or another source?
What This Study Does Not Prove
This study does not prove that oxidative stress causes ME/CFS symptoms or is the primary mechanism of disease—only that it is associated with the condition. The cross-sectional design cannot establish whether oxidative stress precedes ME/CFS or results from it. The findings also do not indicate whether reducing oxidative stress would improve patient outcomes.
Tags
Symptom:Fatigue
Biomarker:AutoantibodiesBlood Biomarker
Method Flag:Small SampleExploratory OnlyWeak Case Definition
Metadata
- DOI
- 10.12659/msm.881699
- PMID
- 21455120
- 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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