Mihaylova, Ivana, DeRuyter, Marcel, Rummens, Jean-Luc et al. · Neuro endocrinology letters · 2007
This study looked at immune cell activation in people with ME/CFS by measuring a protein called CD69 on the surface of immune cells. Researchers found that ME/CFS patients had significantly lower levels of this activation marker on their T cells and natural killer cells compared to healthy people, even though the total number of immune cells was normal. This suggests that immune cells in ME/CFS may have trouble becoming activated properly in response to challenges.
This study provides objective immunological evidence that ME/CFS involves a specific defect in how immune cells activate, rather than simply having abnormal cell numbers. The high diagnostic accuracy (89% ROC AUC) suggests CD69 expression could potentially serve as a biological marker to help identify and study the disease.
This study does not prove that the CD69 defect causes ME/CFS symptoms or is the primary driver of disease—it only shows an association. The study cannot determine whether this immune abnormality is a cause, consequence, or contributing factor to the condition. Additionally, measuring activation in response to laboratory stimulation may not fully reflect how immune cells behave in the body during actual illness.
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
Mihaylova, Ivana, DeRuyter, Marcel, Rummens, Jean-Luc, Bosmans, Eugene, & Maes, Michael (2007). Decreased expression of CD69 in chronic fatigue syndrome in relation to inflammatory markers: evidence for a severe disorder in the early activation of T lymphocytes and natural killer cells.. Neuro endocrinology letters. https://pubmed.ncbi.nlm.nih.gov/17693977/
BibTeX
@article{mecfsatlas-mihaylova-2007-decreased-expression,
author = {Mihaylova, Ivana and DeRuyter, Marcel and Rummens, Jean-Luc and Bosmans, Eugene and Maes, Michael},
title = {Decreased expression of CD69 in chronic fatigue syndrome in relation to inflammatory markers: evidence for a severe disorder in the early activation of T lymphocytes and natural killer cells.},
journal = {Neuro endocrinology letters},
year = {2007},
note = {PubMed: 17693977},
url = {https://www.mecfsatlas.com/evidence/mihaylova-2007-decreased-expression},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/mihaylova-2007-decreased-expression
Contribute
Private, reviewed by a human. Not a public comment thread.