Giménez-Orenga, Karen, Pierquin, Justine, Brunel, Joanna et al. · Brain, behavior, & immunity - health · 2025 · DOI
Researchers measured specific proteins and immune markers in the blood of people with post-COVID-19 condition, ME/CFS, and fibromyalgia to see if they could tell these conditions apart. They found that certain blood markers could distinguish post-COVID-19 condition from the other two conditions with very high accuracy, suggesting these illnesses may involve different immune patterns even though their symptoms overlap significantly.
Accurate differential diagnosis between post-COVID-19 condition, ME/CFS, and fibromyalgia remains clinically challenging due to overlapping symptoms; this study provides potential objective blood-based biomarkers that could improve diagnostic accuracy and guide targeted treatments. Identifying distinct immunological signatures may open therapeutic pathways specific to each condition and help explain why some COVID-19 patients develop ME/CFS-like illness while others do not.
This study does not establish whether the identified biomarkers are causative or merely correlated with disease status, nor does it prove these conditions have fundamentally different underlying mechanisms—only that their immune profiles differ measurably. The high specificity for post-COVID-19 condition does not necessarily apply to all patient populations, and findings require validation in prospective, longitudinal cohorts before clinical implementation.
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 →
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
Giménez-Orenga, Karen, Pierquin, Justine, Brunel, Joanna, Charvet, Benjamin, Martín-Martínez, Eva, Lemarinier, Margot, et al. (2025). Blood parameters differentiate post COVID-19 condition from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia.. Brain, behavior, & immunity - health. https://doi.org/10.1016/j.bbih.2025.101058
BibTeX
@article{mecfsatlas-gimnez-orenga-2025-blood-parameters,
author = {Giménez-Orenga, Karen and Pierquin, Justine and Brunel, Joanna and Charvet, Benjamin and Martín-Martínez, Eva and Lemarinier, Margot and Fried, Steven and Lucas, Alexandre and Perron, Hervé and Oltra, Elisa},
title = {Blood parameters differentiate post COVID-19 condition from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia.},
journal = {Brain, behavior, & immunity - health},
year = {2025},
doi = {10.1016/j.bbih.2025.101058},
note = {PubMed: 40726775},
url = {https://www.mecfsatlas.com/evidence/gimnez-orenga-2025-blood-parameters},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-27. https://www.mecfsatlas.com/evidence/gimnez-orenga-2025-blood-parameters
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