UK scientists have developed a new blood test to help early detection of Parkinson’s disease before the main symptoms occur.
A poll of more than 2,000 patients conducted in 2020 by non-profit organisation Parkinson’s UK found 26% reported being misdiagnosed with a different disease before receiving an eventual Parkinson’s diagnosis (a neurological condition affecting a person’s movement and thinking skills).
While there is currently no cure, the earlier it is detected the more treatment and care a person can receive to help slow disease progression.
Oxford University research team leader Professor George Tofaris told medicalnewstoday.com: ‘The brain has a certain reserve of dopamine and ability to compensate.’
This means that, by the time people with Parkinson’s disease present to a clinic with the familiar movement disorder, 60% or so of dopamine-producing nerve cells ‘have already died and neuro- degeneration is often widespread.
‘At this stage, it is difficult to restore the neuronal networks. On the other hand, if we could detect the pathology early – before this critical threshold is reached – then we are more likely to be effective with disease-modifying therapies and the impact of any benefit is likely to be longer lasting even if ‘cure’ is not achieved.’
He added: ‘We know from different studies that the pathology starts more than a decade before the clinical presentation. What we are lacking is a scalable biomarker to identify these changes, ideally a blood test.
‘Therefore the need for such a test goes hand-in-hand with the urgent need for disease-modifying therapies.’
The new blood test developed by Professor Tofaris and his team, whose study was published in the journal JAMA Neurology, focused on detecting alpha-synuclein proteins – which are involved in the development of Parkinson’s disease – by isolating extracellular vesicles from nerve cells circulating in the blood, allowing them to measure their alpha-synuclein content.
They tested 365 people at risk for Parkinson’s disease, as well as 282 healthy controls and 71 with genetic or sporadic Parkinson’s disease.
The scientists found those with the highest risk of developing Parkinson’s disease (more than 80% probability) had a two-fold increase in alpha-synuclein levels in neuronal extracellular vesicles.
They also found the test could accurately differentiate them from those with low-risk or healthy controls and could distinguish between a person with a high Parkinson’s disease risk from a healthy control with a 90% probability.
Professor Tofaris summed up: ‘My hope is that in the future, a blood test such as this one, possibly in combination with a questionnaire or a limited assessment, will be implemented for screening to identify Parkinson’s early for the instigation of a disease-modifying intervention, as we currently do for certain cancers or screening programs for cardiovascular risk factors.’
