Seifert, Martina, Schäfers, Johannes, Douglas, Fiona F et al. · International journal of molecular sciences · 2026 · DOI
Researchers examined tiny packages of proteins and molecules (called extracellular vesicles) found in the blood of ME/CFS patients to see if they contain unique signatures that could help diagnose the disease. They found that certain proteins and a specific small molecule called hsa-let-7b-5p were different in ME/CFS patients compared to healthy people, and these differences were linked to worse fatigue, pain, and immune problems. This discovery suggests that blood tests measuring these substances could eventually help doctors diagnose ME/CFS and better understand who has the disease.
ME/CFS currently lacks objective diagnostic tests, making early recognition and confirmation difficult for patients. This research identifies candidate biomarkers in blood that could enable development of diagnostic tests and help researchers understand disease mechanisms. If validated in larger studies, these findings could transform ME/CFS diagnosis from subjective clinical criteria to objective laboratory measurements.
This study does not prove that these molecular changes cause ME/CFS or that they are specific to ME/CFS—only that they differ from healthy controls in this small group. The small sample size means findings must be replicated in larger, independent cohorts before clinical use. The study also does not establish whether these markers can distinguish ME/CFS from other post-infectious illnesses or chronic 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 →
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
Seifert, Martina, Schäfers, Johannes, Douglas, Fiona F, Schwarzburg, Carl, Boristowski, Diana, Birke, Anne, et al. (2026). Extracellular Vesicle Protein and MiRNA Signatures as Biomarkers for Post-Infectious ME/CFS Patients.. International journal of molecular sciences. https://doi.org/10.3390/ijms27052314
BibTeX
@article{mecfsatlas-seifert-2026-extracellular-vesicle,
author = {Seifert, Martina and Schäfers, Johannes and Douglas, Fiona F and Schwarzburg, Carl and Boristowski, Diana and Birke, Anne and Klein, Oliver and Sotzny, Franziska and Rubarth, Kerstin and Windzio, Lara and Beez, Christien M and Peters, Claudia Kedor and Wittke, Kirsten and Scheibenbogen, Carmen and Greco, Anna},
title = {Extracellular Vesicle Protein and MiRNA Signatures as Biomarkers for Post-Infectious ME/CFS Patients.},
journal = {International journal of molecular sciences},
year = {2026},
doi = {10.3390/ijms27052314},
note = {PubMed: 41828537},
url = {https://www.mecfsatlas.com/evidence/seifert-2026-extracellular-vesicle},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/seifert-2026-extracellular-vesicle
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