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Neurofilament Light Chain

Neurofilament light chain (NfL) is a neuronal scaffolding protein that is exclusively expressed in the large caliber axons of neurons. During axonal damage, NfL is released into CSF and subsequently into blood. Concentration is 40 times higher in CSF than in blood. NfL concentration in blood is proportional to the degree of axonal damage in a variety of neurological disorders, including traumatic brain injury, amyotrophic lateral sclerosis, multiple sclerosis, frontotemporal dementia, Alzheimer disease, and other neurodegenerative diseases.

Plasma NfL concentrations increase with age in healthy individuals.  NfL levels in the blood of healthy controls increase by 2.2% per year between the ages of 18 years and 70 years. Reference values are age dependent.

NfL levels may be elevated in patients with stroke chronic kidney disease, atrial fibrillation, and myocardial infarction.


Gaetani L et al. Neurofilament light chain as a biomarker in neurological disorders,
J Neurol Neurosurg Psychiatry, 2019 Aug;90(8):870-881.

Thebault S et al. Blood neurofilament light chain: The neurologist’s troponin? Biomedicines 2020;8:523

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