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Pathophysiological mechanisms of post-exertional malaise: an integrative analysis based on the metabolism-immune-neuro interaction model. — ME/CFS Atlas

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Pathophysiological mechanisms of post-exertional malaise: an integrative analysis based on the metabolism-immune-neuro interaction model.

Jin, Hongjiao, An, Yi, Huang, Jingwei et al. · Frontiers in immunology · 2026 · DOI

Quick Summary

This systematic review proposes a framework for understanding post-exertional malaise (PEM)—the worsening of symptoms after mild activity—by examining how energy production, immune activation, and brain inflammation may be associated with each other in people with Long COVID and chronic fatigue conditions. The authors suggest that in vulnerable individuals, exercise may trigger an abnormal cascade involving damaged mitochondria (cellular energy factories), inflammatory molecules, and changes in how the brain perceives fatigue and pain. However, this is a theoretical model based on existing literature; individual mechanisms have not been directly tested in a single study.

Why It Matters

This review is relevant to ME/CFS because it examines PEM—a defining feature of ME/CFS—and proposes a multi-system framework that may help explain why symptoms worsen after activity. By drawing parallels between Long COVID and chronic fatigue conditions, the authors highlight potential common pathways that could guide future research into ME/CFS mechanisms. However, the framework remains theoretical and has not yet been empirically validated in ME/CFS-specific cohorts.

Observed Findings

In chronic debilitating conditions including Long COVID and chronic fatigue, metabolic abnormalities and indicators of mitochondrial dysfunction (impaired ATP synthesis, reactive oxygen species overproduction, metabolic byproduct accumulation) are associated with exercise intolerance.
In these populations, exercise-induced metabolic stress is associated with activation of immune pathways (NLRP3 inflammasome, pro-inflammatory cytokine release) in vulnerable individuals, contrasting with adaptive mitochondrial enhancement observed in healthy exercisers.
Peripheral inflammatory markers are observed alongside alterations in the blood-brain barrier, vagal signaling, glial activation, and neuroinflammatory responses in post-infectious and long-duration fatigue conditions.
Altered perception of fatigue, pain, and interoceptive signals is associated with changes in brain regions including the insular cortex in these populations.
Mitochondrial dysfunction in neurons is proposed as one candidate mechanism for central energy depletion and cognitive symptoms, though direct evidence in intact PEM populations is limited.

Inferred Conclusions

The authors conclude that PEM may arise from a self-perpetuating interaction among mitochondrial dysfunction, immune activation, and neuroinflammation, forming an 'energy exhaustion–inflammation amplification' loop.
They propose that this integrated framework may explain the chronic and multi-system nature of PEM symptoms across distinct post-infectious and chronic fatigue conditions.
The authors suggest that a multi-target, collaborative intervention approach addressing metabolism, immunity, and neural signaling may be needed to disrupt the proposed pathological cycle, though no specific interventions are endorsed by the review itself.

What This Study Does Not Prove

This review does not establish that any single mechanism causes PEM; it presents associations and proposed interactions observed in existing literature. It does not confirm that the integrated 'metabolism-immune-neuro' model accurately reflects biology in any individual patient or that it applies uniformly to ME/CFS (as the source population is overlapping, including Long COVID). It does not test or validate the proposed vicious cycle experimentally, and does not recommend specific treatments based on this framework.

Topics

Neuroinflammation Energy Metabolism Immune System Cognitive Impairment Post-Exertional Malaise

Metadata

DOI: 10.3389/fimmu.2026.1774310
PMID: 42051540
Evidence level: Higher-level evidence type — systematic reviews, meta-analyses, guidelines, or major syntheses (study type, not a quality guarantee)
Last updated: 30 April 2026

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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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The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.

Primary citation

Jin, Hongjiao, An, Yi, Huang, Jingwei, Luo, Tingting, & Wu, Xi (2026). Pathophysiological mechanisms of post-exertional malaise: an integrative analysis based on the metabolism-immune-neuro interaction model.. Frontiers in immunology. https://doi.org/10.3389/fimmu.2026.1774310

BibTeX

@article{mecfsatlas-jin-2026-pathophysiological-mechanisms,
  author  = {Jin, Hongjiao and An, Yi and Huang, Jingwei and Luo, Tingting and Wu, Xi},
  title   = {Pathophysiological mechanisms of post-exertional malaise: an integrative analysis based on the metabolism-immune-neuro interaction model.},
  journal = {Frontiers in immunology},
  year    = {2026},
  doi     = {10.3389/fimmu.2026.1774310},
  note    = {PubMed: 42051540},
  url     = {https://www.mecfsatlas.com/evidence/jin-2026-pathophysiological-mechanisms},
}

Atlas snapshot reference

ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-05. https://www.mecfsatlas.com/evidence/jin-2026-pathophysiological-mechanisms

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