How a new Parkinson’s blood test could speed up diagnosis by at least 10 years

A new blood test has the potential to diagnose Parkinson’s disease at least a decade earlier than existing methods because it detects a key cause of the condition, its developers say.

If the new diagnostic tool is show to be safe and effective in larger trials and becomes available on the NHS, it could have a transformational effect on the lives of thousands of people every year.

It could detect the disease more than 10 years earlier than at the moment so that existing treatments – and promising new ones under development – could be given at a time when they can be far more effective, before the nervous system becomes severely damaged.

“Detecting Parkinson’s earlier and being able to diagnose it accurately using a biological test would be a major step forward,” Claire Bale, associate director of research at Parkinson’s UK, told i.

“It would provide a much smoother and improved experience for the thousands of people who are diagnosed with the condition every year, enabling them to access treatment and support sooner.

“We also hope that detecting Parkinson’s early will be key to stopping or preventing the condition in the future when we have treatments that can stop the progression,” she added.

Laurie Sanders, of the Duke Clinical Research Institute in North Carolina, said: “Currently, Parkinson’s disease is diagnosed largely based on clinical symptoms after significant neurological damage has already occurred. A simple blood test would allow us to diagnose the disease earlier and start therapies sooner.”

The new test works by looking at damage to mitochondria, the energy producing “batteries” that power cells, that stop working properly in the brain cells affected in Parkinson’s.

The research breakthrough with this new test is finding that these mitochondrial problems can also be detected in the blood of people with the condition.

“We have demonstrated that mitochondrial DNA damage levels in the blood can discriminate between those with Parkinson’s disease and those that do not,” said Dr Sanders.

“We have tested our assay [technique] in multiple groups of humans. However, we still have work to do in features of the assay so that it is ready for wide usage. We are already doing this. Our next steps include a clinical trial, but the details are still being worked out,” she said.

She said preliminary findings suggest the test is very accurate. On the standard measure of accuracy, a reading of between 0.8 to 0.9 is considered “excellent” – with our test scoring 0.84 to 0.85, Dr Sanders said.

Professor Charalampos Tzoulis, of the University of Bergen, who was not involved in the research, said the work
“advances the understanding of how mitochondrial dysfunction is involved in Parkinson’s disease”.

According to Parkinson UK’s Ms Bale, a diagnostic technique that can detect the condition much earlier is badly needed – with diagnosis typically slow, inaccurate and with misdiagnoses common.

“Currently most people are diagnosed with Parkinson’s based on symptoms alone, and because the early signs of Parkinson’s can be varied – including sleep problems, constipation, loss of sense of smell, changes in mood as well as difficulties with movement – this process is far from straightforward.”

She points to a Parkinson’s UK poll finding that more than a quarter were misdiagnosed with a different condition before receiving the correct Parkinson’s diagnosis – with the process sometimes taking as many as four years or more.

However, she is hopeful that the situation may soon improve, predicting that there will be a new definitive, biological, diagnostic test for Parkinson’s ready for use within the next few years – which may take the form of this blood test or one of the other tests under development, or both.

“This is currently a very active area of research, with many different possible tests being explored which is extremely encouraging,” Ms Bale said.

Last week, a separate study found that 3D eye scans widely used in high street opticians could help to identify people at high risk of developing Parkinson’s disease up to seven years before they have symptom.

The researchers, from UCL and Moorfields Eye Hospital, used AI to compare OCT eye scan data from 700 patients who went on to develop Parkinson’s disease with more than a hundred thousand patients who did not.

This revealed differences in the thickness of the inner retinal cell layer, which appeared to be associated with the development of Parkinson’s.

“While we are not yet ready to predict whether an individual will develop Parkinson’s, we hope that this method could soon become a pre-screening tool for people at risk of disease,” said Siegfried Wagner of UCL and Moorfields.

And last September, Manchester University scientists revealed a new method to detect Parkinson’s disease by analysing sebum – the oily substance on the surface of the skin – using a skin swab.

They found that lipids – fatty compounds – were present at significantly higher levels in the sebum of people with Parkinson’s than in that of people without the disease.

“We are tremendously excited by these results which take us closer to making a diagnostic test for Parkinson’s Disease that could be used in clinic,” Professor Perdita Barran at The University of Manchester, said at the time.

Meanwhile, in November, scientists at ETH Zurich, in Switzerland, found a group of proteins in cerebrospinal fluid (CSF) in the brain and spine that have different shapes in healthy people and people with Parkinson’s disease.

They hope these proteins may serve as a ‘biomarker’ for Parkinson’s disease that may be used as the basis of a screening or diagnostic test.

The prospect of a new diagnostic test comes amid hopes of more effective treatments for Parkinson’s Disease in the coming years.

Scientists at the University of Bergen, in Norway, have developed a pill that preliminary tests suggest can slow down or even arrest the progression of Parkinson’s disease, that could be available within five years.

A trial indicated that taking nicotinamide riboside (NR), a naturally-occuring form of vitamin B3, can reduce inflammation and help control symptoms.

The finding has raised hopes that the vitamin, which is found in fruit, vegetables, meat and milk, could form the basis of the first drugs to successfully slow the development of Parkinson’s – as well as help manage its symptoms.

Professor Dag Aarsland, Professor of Old Age Psychiatry, King’s College London, who was not involved in developing the new blood test, said: “There is huge development in biofluid diagnostics for Parkinson’s Disease.”