Patients could benefit from earlier treatment for Parkinson’s disease following the development of a new blood test from researchers at the University of Oxford.
The test screens people at risk of Parkinson’s disease by using a biomarker called alpha-synuclein – a protein which Oxford researchers have already demonstrated has an elevated presence in patients with Parkinson’s disease, but not in people with Parkinson’s like conditions.
When brain cells cannot handle this protein properly, clumps of alpha-synuclein form which subsequently damage nerve cells and lead to the typical Parkinson’s symptoms.
Oxford University researchers investigated the potential of measuring a subtype of extracellular vesicles – extracellular vesicles are characterised as nanoparticles which circulate in the blood and are released by all cell types in the body.
Their test involved isolating nerve cell extracellular vesicles from the blood and measuring their alpha-synuclein content.
After analysing 365 people at risk of Parkinson’s, 282 healthy controls and 71 people with the disease, the researchers found that those with a high risk of Parkinson’s had double the amount of alpha-synuclein.
George Tofaris, a professor of neurology at Oxford University, explained: “A robust assay is crucial because neuronally-derived extracellular vesicles constitute less than 10% of all circulating vesicles, and 99% of alpha-synuclein in blood is released from peripheral cells, mostly red blood cells.”
According to the University of Oxford, the test could identify someone with a high risk of developing Parkinson’s from a healthy control with a 90% probability.
Given Parkinson’s starts more than 10 years before the onset of symptoms, the test could be used to identify those who could benefit most from clinical trials and disease-modifying therapies earlier.
Further research indicated the test could also accurately identify people who had not yet developed a movement disorder or related dementia, but had evidence of neurodegeneration from imaging, or pathology detected via a spinal fluid assay.
In a small group of 40 people who eventually developed Parkinson’s and dementia, the blood test accurately found over 80% of cases up to seven years before diagnosis.
Prof Tofaris added: “Collectively our studies demonstrate how fundamental investigations in alpha-synuclein biology can be translated into a biomarker for clinical application, in this case for the identification and stratification of Parkinson’s risk.
“A screening test that could be implemented at scale to identify the disease process early is imperative for the eventual instigation of targeted therapies as is currently done with screening programmes for common types of cancer.”
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