Blood test for Parkinson's disease: Hopes for treatment research

Researchers have developed a simple blood test that uses artificial intelligence to predict Parkinson's disease years before symptoms appear.

The researchers hope that this technology will lead to affordable finger-prick testing, allowing earlier diagnosis and the discovery of treatments that can slow the progression of the disease.

The charity Parkinson's UK said it was a “major step forward” in the quest for a non-invasive, patient-friendly test.

But larger trials are needed to prove its accuracy.

Parkinson's disease affects around 10 million people worldwide, with more than 150,000 in the UK.

Many people are diagnosed with symptoms such as tremors, movement disorders and memory problems caused by the death of nerve cells in the part of the brain that controls movement.

Although there are treatments to help manage symptoms, there is no cure, and no treatment can slow or stop the progression of the disease.

Researchers led by scientists from University College London and the University Medical Center of Gottingen in Germany took blood samples from a group of people with Parkinson's disease and a group of people without it, and identified eight key proteins most likely to predict the development of Parkinson's.

The researchers then tested the blood of 72 patients at risk of Parkinson's and other brain diseases for the eight protein markers, and followed them for 10 years.

Using AI tools, the researchers accurately predicted that 16 people would develop Parkinson's disease up to seven years before symptoms began to appear.

Overall, the test predicted that 79 percent of patients would develop the disease, but the researchers are following up with additional patients to confirm its accuracy.

The marker is directly linked to inflammation and protein degradation and could potentially be used to develop new drug treatments for Parkinson's disease, the researchers said.

“At the moment it's like closing the stable door after the horse has run away,” said lead author Professor Kevin Mills, from the Great Ormond Street Institute of Child Health, University of London.

“We need to start treatments before patients develop symptoms.”

“The condition is diagnosed when neurons have already been lost,” said co-author Dr Jenny Hellqvist from University College London.

“We need to protect neurons rather than waiting until they die.”

Parkinson's symptoms usually start out mild and progress gradually.

The main symptoms affect movement and include:

• The tremors usually start in the hands and arms.
• Slow movements, e.g. walking with very small steps
• Stiffness and tightness in muscles can make it difficult to move around or make facial expressions

In the brain, a protein called alpha-synuclein builds up, causing nerve cells to lose their ability to produce a key chemical called dopamine, which is associated with movement.

NHS – Parkinson's Disease

The researchers now plan to develop a simpler test – one that involves putting a drop of blood on a card and mailing it to a lab – to see if it can predict Parkinson's even earlier.

Professor David Dexter, lead researcher at Parkinson's UK, which funded the research, said: “These findings add to the recent flurry of activity to find simpler ways to test and measure Parkinson's disease.

The test could potentially distinguish Parkinson's from other similar diseases, he added.

Ray Chaudhri, professor of movement disorders and neurology at King's College Hospital and King's College London, said a blood test to diagnose and predict Parkinson's disease was a “huge unmet need”, but questioned whether the step was ethical in the absence of a cure.

Michel Bendolscolo, professor of biophysics at the University of Cambridge, said the test could be carried out with equipment already available at major hospitals and could help recruit people at risk of the disease for clinical trials.

“It could potentially be used to monitor the effectiveness of treatments,” he said.

This study Nature Communications.