Researchers led by a team at Chalmers University of Technology in Sweden have identified biological markers that appear in the earliest stages of Parkinson’s disease, before major damage occurs in the brain. These early changes leave detectable traces in the blood, but only for a short time. The findings highlight a critical opportunity to both diagnose the disease earlier and explore treatments while the brain is still largely intact. The researchers believe blood tests based on this work could begin to be tested in healthcare settings within five years.
Parkinson’s disease affects more than 10 million people worldwide and is considered an endemic condition. As populations continue to age, that number is expected to more than double by 2050. Despite its growing impact, there is currently no cure and no widely used screening method that can detect the disease early, before it causes significant and often irreversible brain damage.
New Study Points Toward Earlier Diagnosis
The findings were published in the journal npj Parkinson’s Disease by a research team from Chalmers University of Technology and Oslo University Hospital in Norway. The study describes major progress toward identifying Parkinson’s during its earliest phase, well before classic movement-related symptoms appear.
“By the time the motor symptoms of Parkinson’s disease appear, 50 — 80 per cent 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,” says Danish Anwer, a doctoral student at the Department of Life Sciences at Chalmers and the study’s first author.
A Long and Overlooked Early Phase
Parkinson’s disease develops slowly. In many patients, the early phase can last up to 20 years before noticeable motor symptoms fully emerge. During this time, changes are already occurring inside cells.
The researchers focused on two biological processes believed to play a role at this early stage. One is DNA damage repair, the system cells use to detect and fix genetic damage. The other is the cellular stress response, a protective reaction that helps cells survive by shifting energy away from routine tasks and toward repair and defense.
Machine Learning Reveals a Unique Pattern
Using machine learning and other advanced analytical methods, the team identified a distinct pattern of gene activity related to DNA repair and stress response. This pattern appeared only in people in the early phase of Parkinson’s disease. It was not seen in healthy individuals or in patients who had already developed motor 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. 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,” says Annikka Polster, Assistant Professor at the Department of Life Sciences at Chalmers, who led the study.
Why Blood-Based Testing Matters
Scientists around the world have been searching for reliable early indicators of Parkinson’s disease, including markers found through brain imaging and spinal fluid analysis. However, none of these approaches has yet led to a validated screening test suitable for widespread use before symptoms begin.
“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.
Blood Tests Could Reach Healthcare Within Years
The next phase of the research will focus on understanding exactly how these early biological mechanisms work and on developing tools that make them easier to detect.
The researchers estimate that within five years, blood tests designed to identify Parkinson’s disease at an early stage could begin to be tested in healthcare systems. Over the longer term, the findings may also support the development of treatments aimed at slowing or preventing the disease.
“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,” says Polster.
More About the Scientific Article
The study Longitudinal assessment of DNA repair signature trajectory in prodromal versus established Parkinson’s disease has been published in npj Parkinson’s Disease. The authors are Danish Anwer, Nicola Pietro Montaldo, Elva Maria Novoa-del-Toro, Diana Domanska, Hilde Loge Nilsen and Annikka Polster. The researchers work at Chalmers University of Technology, Sweden, and Oslo University Hospital, Norway.
The research has been funded by Chalmers Health Engineering Area of Advance, Sweden, the Michael J Fox Foundation, the Research Council of Norway, NAISS (National Academic Infrastructure for Supercomputing in Sweden) and the Swedish Research Council.
More About Parkinson’s Disease
Parkinson’s disease is a neurological disorder that interferes with the brain’s ability to control movement. It progresses slowly and most often begins after the age of 55 — 60. Parkinson’s is the second most common neurodegenerative disease worldwide, after Alzheimer’s disease. More than 10 million people have been diagnosed globally, and that number is projected to more than double by 2050.
Sources: The Swedish Parkinson’s Association, The BMJ, global projection study, 2024
Parkinson’s Disease Symptoms and Progression
Early symptoms
REM sleep behavior disorder: The person acts out dreams during REM sleep, often with movements or sounds. Reduced sense of smell Constipation Depression Anxiety
Motor symptoms later in the disease
Slow movements Rigidity and instability Tremors Involuntary muscle contractions