Neurofilament light chain (NfL) is a protein found inside neurons in the brain. If axons die, for example, due to disease, NfL is released from the brain and can be measured in blood. Thus, rising levels of NfL in the blood may suggest increasing levels of neuronal cell death associated with neurological conditions.
In the early phase of Parkinson’s disease, high levels of NfL in brain fluid are associated with more severe motor symptoms and shorter survival. Those with elevated blood NfL levels also had worse cognitive decline, brain atrophy & motor score.
NfL is being explored as a biomarker in multiple neurodegenerative conditions such as Parkinson’s and Alzheimer’s disease, as well as stroke, multiple sclerosis and traumatic brain injury. It is also being incorporated into the drug approval process.