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Involvement of autoantibodies against G protein-coupled receptors in post-COVID condition and Chronic Fatigue Syndrome. — ME/CFS Atlas

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Involvement of autoantibodies against G protein-coupled receptors in post-COVID condition and Chronic Fatigue Syndrome.

Azcue, N, Prada, A, Del Pino, R et al. · Scientific reports · 2026 · DOI

Quick Summary

Researchers compared immune markers called autoantibodies in people with post-COVID condition, ME/CFS, and healthy controls. They found that people with ME/CFS had higher levels of antibodies against certain nerve receptors (β2 adrenergic), and these antibodies were associated with autonomic nervous system problems and memory changes. However, this is a single cross-sectional study, and autoimmunity remains one of several proposed mechanisms—it is not yet clear whether these antibodies are a cause or a consequence of ME/CFS.

Why It Matters

This study identifies autoantibodies against specific nerve receptors that are associated with autonomic dysfunction and cognitive impairment in ME/CFS, potentially supporting the investigation of autoimmunity as one contributor to disease pathophysiology. If validated, these autoantibodies could serve as biomarkers to stratify patients or identify subgroups amenable to targeted immunotherapies. However, the overlapping population (post-COVID and ME/CFS studied together) means findings in post-COVID may not directly apply to ME/CFS, and vice versa.

Observed Findings

ME/CFS patients showed significantly elevated β2 adrenergic autoantibody titers compared to post-COVID and healthy controls (p = 0.046).
β2 adrenergic autoantibodies were associated with increased autonomic symptoms in post-COVID (r = 0.27, p = 0.048).
β2 adrenergic autoantibodies were associated with sympathovagal imbalance in ME/CFS (r = 0.45, p = 0.001).
In ME/CFS, muscarinic autoantibodies (M1, M3, M4 subtypes) were positively correlated with verbal and working memory performance.
Post-COVID patients showed more borderline or pathological M3 muscarinic autoantibody results compared to healthy controls.

Inferred Conclusions

The authors interpret these findings as evidence that distinct autoantibody profiles in post-COVID and ME/CFS suggest different immunological mechanisms between the two conditions.
They propose that autoantibodies against adrenergic and muscarinic receptors may contribute to autonomic and cognitive dysfunction in these populations, warranting investigation of autoantibodies as biomarkers and therapeutic targets.
By analogy, the association between autoantibodies and specific symptom domains may indicate that ME/CFS represents a heterogeneous condition with autoimmune subgroups.

Remaining Questions

Do these autoantibodies precede symptom onset, or do they arise secondary to infection or inflammation?

What This Study Does Not Prove

This cross-sectional design does not establish that autoantibodies cause autonomic or cognitive dysfunction—only that they are associated. The study does not prove these autoantibodies are a primary driver of ME/CFS; they may be secondary phenomena or biomarkers of other pathological processes. Case definitions and peer-review status are unknown, limiting generalisability. The findings do not constitute a treatment recommendation and do not identify mechanistic causation.

Topics

Biomarkers Autonomic Nervous System Immune System Cognitive Impairment Long COVID Overlap

Metadata

DOI: 10.1038/s41598-026-49131-9
PMID: 42082542
Evidence level: Single-study or moderate support from human research
Last updated: 5 May 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 →

Cite this study

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

Azcue, N, Prada, A, Del Pino, R, Acera, M, Fernández-Valle, T, Ayo-Mentxakatorre, N, et al. (2026). Involvement of autoantibodies against G protein-coupled receptors in post-COVID condition and Chronic Fatigue Syndrome.. Scientific reports. https://doi.org/10.1038/s41598-026-49131-9

BibTeX

@article{mecfsatlas-azcue-2026-involvement-autoantibodies,
  author  = {Azcue, N and Prada, A and Del Pino, R and Acera, M and Fernández-Valle, T and Ayo-Mentxakatorre, N and Pérez-Concha, T and Murueta-Goyena, A and Lafuente, J V and López de Munain, A and Ruiz Irastorza, G and Ribacoba, L and Gabilondo, I and Tijero-Merino, B and Gómez-Esteban, J C},
  title   = {Involvement of autoantibodies against G protein-coupled receptors in post-COVID condition and Chronic Fatigue Syndrome.},
  journal = {Scientific reports},
  year    = {2026},
  doi     = {10.1038/s41598-026-49131-9},
  note    = {PubMed: 42082542},
  url     = {https://www.mecfsatlas.com/evidence/azcue-2026-involvement-autoantibodies},
}

Atlas snapshot reference

ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-05. https://www.mecfsatlas.com/evidence/azcue-2026-involvement-autoantibodies

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