New blood test could detect Parkinson’s years before symptoms

A team of scientists led by Chalmers University of Technology in Sweden has identified biomarkers that could allow Parkinson’s disease to be detected years before the onset of symptoms. The findings indicate that biological changes linked to the disease can be measured through blood tests during a small early window, which could lead to better diagnosis and future treatment. The discovery also opens new opportunities for drug discovery, including earlier therapeutic intervention and the repurposing or development of drugs targeting these mechanisms.

A growing global challenge

Parkinson’s disease affects more than 10 million people globally and is considered an endemic neurological disorder. As populations age, the number of people living with the disease is expected to more than double by 2050. Despite its prevalence, there is currently no cure and no established method for screening individuals before significant brain damage has occurred.

By the time Parkinson’s is diagnosed, patients often already experience motor symptoms such as tremors and stiffness, which signal advanced loss of nerve cells in the brain.

Detecting damage before symptoms appear

The new study was carried out by researchers from Chalmers University of Technology and Oslo University Hospital in Norway. It focuses on the earliest phase of Parkinson’s, which can last up to 20 years before motor symptoms fully develop.

“By the time the motor symptoms of Parkinson’s disease appear, 50-80 percent of the relevant brain cells are often already damaged or gone. The study is an important step towards facilitating early identification of the disease and counteracting its progression before it has gone this far,” said Danish Anwer, a doctoral student at the Department of Life Sciences at Chalmers and the study’s first author.

An important window of opportunity

The researchers examined two biological processes believed to play a key role early in the disease. One is DNA damage repair, the system cells use to detect and correct genetic damage. The other is the cellular stress response, which allows cells to pause normal activity and prioritise protection and repair.

Using machine learning and advanced analysis, the team identified a distinct pattern of gene activity related to these processes. This pattern was found only in individuals in the early stage of Parkinson’s and not in healthy people or patients with established symptoms.

“This means that we have found an important window of opportunity in which the disease can be detected before motor symptoms caused by nerve damage in the brain appear,” said Annikka Polster, Assistant Professor at the Department of Life Sciences at Chalmers, who led the study. “The fact that these patterns only show at an early stage and are no longer activated when the disease has progressed further also makes it interesting to focus on the mechanisms to find future treatments.”

Towards simple blood tests

While other early indicators of Parkinson’s have been explored, including brain imaging and analysis of spinal fluid, none have yet led to validated screening tools suitable for widespread use.

“In our study, we highlighted biomarkers that likely reflect some of the early biology of the disease and showed they can be measured in blood. This paves the way for broad screening tests via blood samples: a cost-effective, easily accessible method,” says Polster.

Looking ahead to treatment

The team’s next goal is to understand exactly how these early mechanisms work and to develop tools that make detection even simpler. They believe blood tests for early diagnosis could begin clinical testing within five years.

“If we can study the mechanisms as they happen, it could provide important keys to understanding how they can be stopped and which drugs might be effective. This may involve new drugs, but also drug repurposing, where we can use drugs developed for diseases other than Parkinson’s because the same gene activities or mechanisms are active,” the researchers conclude.