AI blood test predicts Parkinson’s seven years before symptoms

A stock image of an older patient going through occupational therapy with a younger nurse
Parkinson's is usually treated after the onset of symptoms - but the new test could change that - Hispanolistic/E+

A simple blood test powered by AI could predict Parkinson’s disease seven years before symptoms appear, a UCL study has found.

There is currently no easily accessible, cheap and reliable test for Parkinson’s, with diagnosis relying on symptom evaluation.

But scientists found eight proteins are present in the blood at abnormal levels in people who will go on to develop the condition.

Blood samples from 99 Parkinson’s patients were studied alongside vials from 72 people suffering with a condition called isolated REM sleep behaviour disorder, in which people physically act out their dreams while asleep – a known precursor to Parkinson’s.

A computer algorithm was able to detect every person with Parkinson’s in the study from their protein profile, and spotted 79 per cent of people who had not yet developed the motor symptoms of Parkinson’s such as tremors and stiffness.

“This specific blood panel indicates molecular events in early stages and could help identify at-risk participants for clinical trials aimed at slowing/preventing motor Parkinson’s disease,” the authors write in their study, published in Nature Communications.

Dopamine replacement

Parkinson’s is thought to be caused by the death of nerve cells in the part of the brain that controls movement.

When these nerve cells die or become impaired, they lose the ability to create a chemical called dopamine.

People with Parkinson’s are currently treated with dopamine replacement therapy after they have already developed symptoms, such as tremors or slowness of movement.

However, early diagnosis and treatment would help protect the dopamine-producing brain cells.

“By determining eight proteins in the blood, we can identify potential Parkinson’s patients several years in advance,” the authors say.

“This means that drug therapies could potentially be given at an earlier stage, which could possibly slow down disease progression or even prevent it from occurring.”

‘A major step forward’

Prof David Dexter, director of research at Parkinson’s UK, said: “This research, co-funded by Parkinson’s UK, represents a major step forward in the search for a definitive and patient-friendly diagnostic test for Parkinson’s.

“Finding biological markers that can be identified and measured in the blood is much less invasive than a lumbar puncture, which is being used more and more in clinical research.”

The work comes as scientists are exploring ways to improve speed of diagnosis and looking for novel ways of alleviating symptoms and slowing down disease progression.

A trial is ongoing, looking at the possibility that an Ozempic-like drug could help slow down symptoms, and UCL scientists recently found eye tests could help identify signs of disease ahead of physical symptoms emerging.

‘We cannot regrow brain cells’

Prof Kevin Mills of UCL, a senior author of the study, said: “As new therapies become available to treat Parkinson’s, we need to diagnose patients before they have developed the symptoms.

“We cannot regrow our brain cells and therefore we need to protect those that we have. At present we are shutting the stable door after the horse has bolted and we need to start experimental treatments before patients develop symptoms.”

He added that with sufficient funding, it is hoped the test will be used by the NHS within two years.

The experts suggest that, with further research, this test could potentially distinguish between Parkinson’s and other conditions that have some early similarities.

Disease afflicts 153,000

According to Parkinson’s UK, around one in 37 people alive today in the UK will be diagnosed with Parkinson’s in their lifetime, and there are 153,000 people already living with the condition.

The researchers are hoping to secure funding to create a simpler test where a drop of blood can be placed on a card and sent to a lab. They hope it might predict Parkinson’s even earlier than this study.