Early research points to a single blood test for a range of neurodegenerative conditions

Brain
Neurofilament light chain enters the bloodstream following damage to nerve fibers, the hallmark of multiple neurodegenerative conditions including Parkinson’s disease, amyotrophic lateral sclerosis and dementia. (Getty Images)

Accurately diagnosing brain diseases has been a daunting challenge for physicians and patients alike, with many relying on invasive spinal tap procedures, expensive imaging scans or somewhat subjective cognition tests. Now, researchers believe they’ve found a way for a simple blood test to give doctors a head start on a wide range of conditions.

Based on a person’s age, abnormally high blood levels of a protein known as neurofilament light chain could help identify people with neurodegenerative conditions such as amyotrophic lateral sclerosis, or the motor neuron disease ALS, as well as frontotemporal dementia and dementia related to Down syndrome.

This one biomarker, when used in a primary care setting, could provide early warnings before outward clinical signs become definitive, or help speed up the course of clinical trials, according to researchers at King’s College London.

“For the first time we have shown across a number of disorders that a single biomarker can indicate the presence of underlying neurodegeneration with excellent accuracy,” said university researcher Abdul Hye, Ph.D., joint senior author on the team’s paper published in Nature Communications. 

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“Though it is not specific for any one disorder, it could help in services such as memory clinics as a rapid screening tool to identify whether memory, thinking or psychiatric problems are a result of neurodegeneration,” Hye added.

Neurofilament light chain enters the bloodstream following damage to nerve fibers, the hallmark of multiple neurodegenerative conditions, including Parkinson’s disease. 

Using a supersensitive test, the researchers found that although elevated protein levels alone could not differentiate between different conditions, it could indicate rarer courses of Parkinson’s, and help identify patients with Down syndrome that may or may not also have dementia.

The researchers’ study analyzed more than 3,100 samples collected from King's College London, Lund University and the Alzheimer's Disease Neuroimaging Initiative.

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“This study shows that neurofilament light chain levels were particularly increased in adults with Down syndrome who have a genetic predisposition for Alzheimer's disease,” said study co-author Andre Strydom, Ph.D., a professor in intellectual disabilities at King's College London. “Furthermore, we showed that those individuals with a dementia diagnosis following onset of Alzheimer's disease had higher levels than those who did not.”

“This suggests that the new marker could potentially be used to improve the diagnosis of Alzheimer's in people with Down syndrome, as well as to be used as biomarker to show whether treatments are effective or not,” Strydom added. “It is exciting that all that could be needed is a simple blood test, which is better tolerated in Down syndrome individuals than brain scans.”