Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome.
van Eeden, Charmaine, Redmond, Desiree, Mohazab, Naima et al. · International journal of molecular sciences · 2023 · DOI
Quick Summary
This study looked at people with a connective tissue disease called systemic sclerosis who also experience severe fatigue (ME/CFS symptoms). Researchers found that fatigued patients had different patterns in how their cells' energy-producing structures (mitochondria) work compared to non-fatigued patients. These differences involved specific genes related to energy production, suggesting that measuring these genes might help doctors identify which systemic sclerosis patients have ME/CFS.
Why It Matters
This research provides the first potential biomarker signature to distinguish ME/CFS in systemic sclerosis patients, addressing a significant gap since no validated biomarkers currently exist for ME/CFS. If validated, these mitochondrial markers could enable earlier identification of fatigued patients and potentially predict more severe disease outcomes, improving clinical management and prognosis.
Observed Findings
ME/CFS-related symptoms were common in early-stage limited cutaneous systemic sclerosis patients.
Fatigued SSc patients showed reduced expression of mitochondrial genes ND4 and CyB compared to non-fatigued patients.
Fatigued SSc patients showed increased expression of mitochondrial gene Cox7C compared to non-fatigued patients.
ND4 and CyB expression levels correlated with markers of systemic sclerosis disease severity.
Inferred Conclusions
An altered mitochondrial electron transport chain gene expression signature distinguishes ME/CFS-affected from non-fatigued systemic sclerosis patients.
Mitochondrial gene expression patterns may serve as potential biomarkers for identifying ME/CFS in systemic sclerosis.
Mitochondrial dysfunction may be associated with both fatigue and disease severity progression in systemic sclerosis.
Remaining Questions
Does this mitochondrial signature predict progression to more severe systemic sclerosis disease outcomes prospectively?
Are the identified mitochondrial changes functional markers of actual energy production impairment, or merely associated transcriptional changes?
Can this mitochondrial signature be used to identify ME/CFS in other rheumatic diseases or in primary ME/CFS without systemic sclerosis?
What This Study Does Not Prove
This study does not prove that mitochondrial dysfunction causes ME/CFS or fatigue—it only shows an association. The cross-sectional design cannot establish whether the mitochondrial changes precede fatigue development or result from it. These findings are specific to systemic sclerosis patients and may not apply to ME/CFS in other conditions or in primary ME/CFS without underlying rheumatic disease.