Chronic fatigue syndrome combines increased exercise-induced oxidative stress and reduced cytokine and Hsp responses.
Jammes, Y, Steinberg, J G, Delliaux, S et al. · Journal of internal medicine · 2009 · DOI
Quick Summary
This study found that people with ME/CFS experience unusual stress on their cells during exercise, particularly involving harmful molecules called free radicals. Their bodies also fail to mount normal protective responses—both in terms of producing protective proteins (heat shock proteins) and inflammatory markers that healthy people produce during exertion. This combination of excessive cellular damage and insufficient protective response may explain why exercise is so difficult for people with ME/CFS.
Why It Matters
This study provides mechanistic evidence for why post-exertional malaise (PEM) occurs in ME/CFS—demonstrating a specific biochemical abnormality in cellular stress response rather than deconditioning. Understanding this protective protein deficiency could lead to targeted therapeutic interventions and validates the biological basis of exercise intolerance in ME/CFS.
Observed Findings
ME/CFS patients had significantly lower baseline levels of Hsp70 and reduced ascorbic acid (RAA) compared to controls
During maximal exercise, ME/CFS patients showed exaggerated and prolonged increase in TBARS (oxidative stress marker) with blunted RAA response
ME/CFS patients displayed absent or significantly reduced IL-6 and TNF-alpha increases during exercise despite oxidative stress
Hsp27 and Hsp70 responses were delayed and marked reduced in ME/CFS patients compared to controls during and after exercise
Muscle membrane excitability (M-wave) was reduced in ME/CFS patients, indicating altered neuromuscular function
Inferred Conclusions
ME/CFS patients exhibit insufficient heat shock protein production in response to exercise-induced oxidative stress
The combination of exaggerated oxidative stress and blunted protective protein response creates a prolonged cellular stress state in ME/CFS
Abnormal muscle membrane excitability may contribute to the reduced exercise capacity observed in ME/CFS patients
Delayed and insufficient Hsp production may be a key mechanism underlying post-exertional malaise in ME/CFS
Remaining Questions
Is the heat shock protein deficiency a primary pathological feature of ME/CFS, or does it develop secondary to other underlying abnormalities?
What This Study Does Not Prove
This study does not prove that low heat shock protein production is the sole cause of ME/CFS or PEM, only that it is associated with altered exercise response in this cohort. The small sample size (n=9 per group) limits generalizability, and the cross-sectional nature prevents determination of whether the Hsp abnormality is primary or secondary. The study also does not establish whether this pattern is unique to ME/CFS or occurs in other post-exertional conditions.
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 →