A blood test for Parkinson’s offers hope for early diagnosis.

They are hopeful that a cheap finger-prick test could provide early diagnoses for Parkinson’s disease and help in finding treatments to slow it down. Parkinson’s UK called it a major step forward in the search for a non-invasive patient-friendly test, but larger trials are needed to confirm its accuracy. Parkinson’s affects nearly 10 million people worldwide and more than 150,000 in the UK, with many being diagnosed after developing symptoms. There is currently no cure or treatment to slow or stop the disease, although therapies exist to help manage symptoms.

The researchers, led by scientists at University College London and University Medical Center Goettingen, Germany, collected blood samples from a group of people with Parkinson’s and another group without the condition. They identified eight major proteins that could predict who would develop the condition. These markers were directly linked to inflammation and protein degradation and could be used to create new drug treatments for Parkinson’s. The team then tested the blood of 72 at-risk patients for disorders like Parkinson’s for these eight protein markers and followed them for 10 years.

Using AI, researchers accurately predicted 16 individuals would develop Parkinson’s, with some cases being identified up to seven years before symptoms appeared. The test overall predicted a 79% likelihood of developing the disease, and ongoing patient follow-ups are being conducted to validate its accuracy.

“At present we are shutting the stable door after the horse has bolted,” senior author Prof Kevin Mills, from UCL’s Great Ormond Street Institute of Child Health, said.

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

Co-author Dr Jenny Hällqvist, from UCL, said: “People are diagnosed when neurons are already lost.

“We need to protect those neurons, not wait till they are gone.”

Parkinson’s symptoms are usually mild at first and develop gradually.

The main symptoms then affect movement and include:

• Rhythmic tremors typically originating in the hand or arm
• Slow, small-step walking
• stiffness and tension in the muscles, which can make it difficult to move around or make facial expressions

In the brain, nerve cells lose the ability to produce dopamine, a key chemical linked to movement, due to the accumulation of alpha-synuclein protein.

NHS – Parkinson’s disease, external

The researchers plan to create a simpler blood test for predicting Parkinson’s, which can distinguish it from similar conditions. Professors involved believe this could fill a significant need and aid in recruiting at-risk individuals for clinical trials. However, ethical concerns have been raised due to the lack of a cure for the disease.

“They could be used to monitor the efficacy of experimental therapeutics,” he said.