Plasma Neurofilament Light Chain: A Potential Biomarker for Neurological Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
Azcue, Naiara, Tijero-Merino, Beatriz, Acera, Marian et al. · Biomedicines · 2024 · DOI
Quick Summary
Researchers measured a protein called neurofilament light chain (NfL) in the blood of ME/CFS patients and healthy people. They found that ME/CFS patients had higher levels of this protein, which suggests nerve damage in the brain and nervous system. The patients with higher NfL levels also had more problems with memory, thinking clearly, and with their autonomic nervous system (the part that controls heart rate and other automatic body functions).
Why It Matters
ME/CFS currently lacks objective diagnostic biomarkers, making diagnosis difficult and delayed. This study provides evidence that NfL—a measurable blood protein—correlates with neurological symptoms in ME/CFS, potentially offering a tool to objectively identify neurological dysfunction and validate patients' cognitive and autonomic complaints.
Observed Findings
ME/CFS patients had significantly higher plasma NfL levels than healthy controls (p<0.05)
Higher NfL levels correlated with worse visuospatial perception (r=-0.42, p≤0.001) in ME/CFS patients
Higher NfL levels correlated with worse verbal memory (r=-0.35, p≤0.005) and visual memory (r=-0.26, p<0.05) in ME/CFS patients
Elevated NfL levels were associated with parasympathetic nervous system dysfunction in ME/CFS (F=9.48, p≤0.003)
NfL levels predicted 17.2% of cognitive test performance variance in ME/CFS but not in healthy controls
Inferred Conclusions
Elevated plasma NfL in ME/CFS patients reflects neuroaxonal damage in the nervous system
NfL may serve as a biomarker for neurological dysfunction in ME/CFS, potentially helping to objectively identify and validate cognitive and autonomic symptoms
The association between NfL and multiple neurological domains (cognitive, autonomic) suggests a common underlying mechanism of nerve cell damage in ME/CFS
Remaining Questions
Does NfL elevation precede ME/CFS symptom onset, or does it develop as a result of the disease? (Longitudinal studies needed)
Can NfL levels predict treatment response or disease progression in ME/CFS patients?
What This Study Does Not Prove
This study cannot prove that elevated NfL causes cognitive or autonomic problems—only that they are associated. The cross-sectional design means we cannot determine whether NfL elevation precedes symptom onset or results from ongoing disease. The findings are preliminary and require validation in larger, longitudinal studies before NfL can be used clinically as a diagnostic or prognostic biomarker.