Scientists at King’s College London have identified a single biomarker that can be used to diagnose a range of neurodegenerative conditions with a simple blood test. The amount of circulating neurofilament light chain protein or NfL in the blood can point to patients with diseases such as dementia or motor neuron disease (ALS), even when their clinical symptoms may be ambiguous.
'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 Abdul Hye, senior author of the study published in Nature Communications. “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,' added Hye.
Neurodegenerative diseases affect an estimated 1 in 6 people worldwide and can take a significant toll on patients’ quality of life. While most of them have no cure, early interventions can help alleviate symptoms and pain and enrich patients’ lifestyles.
Current gold standard tests rely on analysis of the cerebrospinal fluid—the fluid surrounding the brain and spinal cord. This is a painful and invasive procedure, making simple blood tests a better alternative.
The researchers studied blood samples taken from over 3000 study participants, including those diagnosed with neurodegenerative disorders, Down’s syndrome, and depression. Hye and colleagues found that NfL levels were significantly elevated in those with neurodegenerative disease relative to those without cognitive conditions. Patients with Down’s syndrome dementia, motor neuron disease, and frontotemporal dementia exhibited the highest levels of NfL.
Though the test cannot be used to differentiate between individual disorders, it could give physicians valuable insights into the clinical management of these conditions. “Blood-based NfL offers a scalable and widely accessible alternative to invasive and expensive tests for dementia,” explained Hye.
“It is already used as a routine assessment in some European countries such as Sweden or Netherlands, and our age-related cut-offs can provide a benchmark and quick accessible test for clinicians, to indicate neurodegeneration in people who are exhibiting problems in thinking and memory.”