Proteomic signatures in cerebrospinal fluid and their clinical associations in patients with ME/CFS.
Bragée, Björn, Li, Peng, Meadows, Danielle et al. · Scientific reports · 2026 · DOI
Quick Summary
Researchers analyzed fluid from the spinal cords of 31 ME/CFS patients to study 902 different proteins and understand what might be happening in their bodies. They found that patients with certain heart-related symptoms (POTS) had different protein patterns, and those with more severe ME/CFS had changes in immune system and blood clotting proteins. These protein patterns suggest several biological processes may be involved in ME/CFS, providing clues for future research.
Why It Matters
This study provides the first systematic proteomics analysis of CSF in ME/CFS, identifying specific biological pathways associated with disease heterogeneity—particularly POTS comorbidity and severity. These findings offer mechanistic insights that could guide future diagnostic biomarker development and targeted therapeutic investigations for this poorly understood condition.
Observed Findings
Neutrophil degranulation and platelet activation pathways were enriched in patients with POTS comorbidity.
Complement cascade and coagulation-related pathways were enriched in patients with severe ME/CFS.
IGFBP-mediated insulin-like growth factor transport pathway showed association with disease severity.
Four protein ratios reflecting cellular stress, extracellular remodelling, and immune-neuronal interaction were associated with severity ratings.
902 proteins were successfully quantified across cerebrospinal fluid samples.
Inferred Conclusions
Biological heterogeneity in ME/CFS may be reflected in distinct CSF proteome signatures, particularly distinguishing patients with versus without POTS.
Immune activation, coagulation abnormalities, and metabolic pathway dysregulation appear mechanistically linked to disease severity.
Protein ratio approaches may provide more biologically interpretable biomarkers than individual protein analysis for predicting severity.
These findings provide a foundation for hypothesis-driven research in larger, independent cohorts.
Remaining Questions
Do these CSF protein patterns predict disease progression or treatment response, or do they merely reflect current disease state?
What This Study Does Not Prove
This study does not establish causation—protein pattern differences may be consequences rather than causes of ME/CFS. The small sample size (n=31) and lack of independent replication limit definitive conclusions about which proteins would reliably predict disease severity or POTS in larger populations. Cross-sectional design prevents assessment of whether these protein patterns precede symptom onset or change with treatment.