E3 PreliminaryModerate confidencePEM unclearCross-SectionalPeer-reviewedMachine draft
DNA Methylation and Brain-Derived Neurotrophic Factor Expression Account for Symptoms and Widespread Hyperalgesia in Patients With Chronic Fatigue Syndrome and Comorbid Fibromyalgia.
Polli, Andrea, Ghosh, Manosij, Bakusic, Jelena et al. · Arthritis & rheumatology (Hoboken, N.J.) · 2020 · DOI
Quick Summary
This study found that people with ME/CFS and fibromyalgia have unusual patterns in how their genes are regulated, specifically involving a molecule called BDNF that affects pain and nerve function. Researchers measured genetic markers and protein levels in blood samples and found that changes in how BDNF genes are 'switched on and off' may explain why patients experience severe fatigue, pain, and widespread body aches.
Why It Matters
This research identifies a specific molecular mechanism—dysregulated BDNF expression through epigenetic changes—that may underlie both the neurological and pain symptoms in ME/CFS with comorbid fibromyalgia. Understanding this pathway could inform targeted therapeutic approaches and validates the biological basis of these debilitating conditions, moving beyond dismissive psychogenic explanations.
Observed Findings
- Serum BDNF protein levels were significantly higher in CFS/FM patients compared to controls (mean difference 3.31 ng/ml, P=0.001).
- DNA methylation at BDNF exon 9 was significantly lower in CFS/FM patients (mean difference -2.16%, P=0.007).
- The Val66Met (rs6265) BDNF polymorphism mediated the relationship between methylation patterns and protein expression.
- Lower BDNF methylation predicted higher serum BDNF levels (P=0.009).
- Higher serum BDNF levels predicted both symptom severity (P=0.001) and widespread hyperalgesia (P=0.044).
Inferred Conclusions
- BDNF DNA methylation in exon 9 is a key regulator of BDNF protein expression in CFS/FM patients.
- Elevated serum BDNF levels represent a potential biological marker and mechanistic pathway linking epigenetic changes to CFS/FM symptomatology.
- Genetic polymorphisms at the BDNF locus influence the epigenetic regulation of this neurotrophic factor in disease states.
Remaining Questions
- Does BDNF dysregulation occur in ME/CFS patients without comorbid fibromyalgia, and are the mechanisms identical?
- Are the observed methylation changes primary drivers of disease pathology or secondary consequences of illness?
What This Study Does Not Prove
This study does not prove that BDNF dysregulation is the sole cause of ME/CFS/FM or that correcting BDNF levels will cure the disease. The cross-sectional design with measurements only 4 days apart cannot establish causality or temporal progression, and findings in comorbid CFS/FM patients may not generalize to ME/CFS alone or other ME/CFS presentations.
Tags
Symptom:PainFatigue
Biomarker:Gene ExpressionBlood Biomarker
Method Flag:Small SampleExploratory OnlyMixed Cohort
Metadata
- DOI
- 10.1002/art.41405
- PMID
- 32562379
- Review status
- Machine draft
- Evidence level
- Early hypothesis, preprint, editorial, or weak support
- 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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