A blood test that uses artificial intelligence can predict who will develop Parkinson’s disease up to seven years before symptoms appear, researchers say.
The test is designed to work on equipment that is already found in many NHS laboratories and, if validated in a broad population of people, could be made available to the health service within two years.
There are currently no drugs to protect the brain from Parkinson’s disease, but an accurate predictive test would allow clinics to identify people who would benefit most from clinical trials of treatments aimed at the disease slows down or stops.
“At the moment we close the stall door after the horse has bolted,” said Prof Kevin Mills, a senior author of the study at UCL Great Ormond Street Institute of Child. Health. “We need to get to people before they develop symptoms. Prevention is always better than cure.”
Parkinson’s disease is the world’s fastest growing neurodegenerative condition, a trend driven primarily by the aging population. The disease affects more than 150,000 people in the UK and 10 million worldwide. It is caused by a build-up of a protein called alpha-synuclein that damages or destroys nerve cells that produce an important substance called dopamine in a part of the brain called the substantia nigra.
People who develop Parkinson’s may experience tremors, problems with movement and muscle stiffness, but also problems with balance, memory, dizziness and nerve pain. Many receive dopamine replacement therapy, but efforts are underway to find treatments that slow or stop the disease.
To develop the test, scientists at UCL and the University of Göttingen used a machine learning algorithm to detect a signature pattern of eight blood proteins in patients with Parkinson’s. The algorithm was then able to predict future Parkinson’s disease in other patients who provided blood samples. In one patient, the disorder was correctly predicted more than seven years before symptoms appeared. “It is possible that it can go back even further,” says Dr Jenny Hällqvist, at the UCL Institute of Neurology, and first author of the study published in Nature communication.
Prof Roger Barker, a consultant neurologist specializing in Parkinson’s at the University of Cambridge and Addenbrooke’s Hospital, said that if validated by other groups, the test opened up the possibility of diagnosing Parkinson’s in the very earliest stages. enabling patients to be enrolled in clinical trials when the disease process has just begun. “As such, we can treat people with Parkinson’s with disease-modifying therapies before they have lost many cells in their brain,” he said. “Of course, we still need to find such therapies, but this study is a step in the right direction.”
Prof Ray Chaudhuri, the medical director of the Parkinson Foundation International Center of Excellence, said there was a “massive unmet need” for blood tests that predict and diagnose Parkinson’s, but warned that such tests came with “huge challenges”.
“Parkinson’s is not a single disease but a syndrome and can present in different ways,” he said. “As such, management varies and one size does not fit all. It is unlikely that the forecast will identify these subgroups at this stage.” Without effective treatments, an early diagnosis raises significant ethical issues, he added, as well as potentially affecting patients’ insurance policies.
“The process helps us to have a group of people with Parkinson’s who may be ready or suitable for future trials of neuroprotective molecules,” Chaudhuri said. “Furthermore, there is preliminary evidence that physical activity and programmed exercise in such “dangerous” people with Parkinson’s benefits can be beneficial in possibly slowing down the course of the disease.”
