A simple blood test may one day detect the earliest signs of Parkinson’s disease years before the most recognizable symptoms appear, according to new research focused on DNA repair and cellular stress.
Scientists have previously linked DNA repair and the way cells adapt to stress with Parkinson’s. In this new study, researchers identified blood-based biomarkers tied to those processes in people diagnosed with early-stage Parkinson’s disease, a phase that can begin up to 20 years before the main symptoms become obvious.
Researchers from Chalmers University of Technology in Sweden and the University of Oslo in Norway say the findings could help lead to new ways of detecting Parkinson’s earlier, and possibly even preventing the disease from developing.
“We highlighted biomarkers that likely reflect some of the early biology of the disease and showed they can be measured in blood,” said Annikka Polster, a biostatistician at the University of Oslo.
“This paves the way for broad screening tests via blood samples: a cost-effective, easily accessible method.”
As Parkinson’s disease progresses, dopamine-producing neurons die, affecting movement, thinking, and memory. In recent years, studies have suggested that reduced cellular resilience and problems with DNA maintenance may contribute to this damage.
Over three years, the researchers tracked gene expression in blood samples from 188 healthy control participants, 393 people with fully developed Parkinson’s, and 58 people with prodromal Parkinson’s, the early stage when the disease is beginning to develop in the brain.
By comparing samples from all three groups, the study found that changes in genes related to DNA repair and cell stress responses, along with their effects on blood cells, could distinguish healthy people from those with prodromal Parkinson’s with a high degree of accuracy, reaching up to 91% in some cases.
Notably, the researchers did not observe the same cell-stress markers in the blood of people with fully developed Parkinson’s. It is almost as if the early stages of Parkinson’s trigger an emergency response in cells, a response that later fades as the disease advances.
“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,” Polster said.
“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.”
By the time the classic movement problems and tremors associated with Parkinson’s appear, significant damage has often already occurred in the brain. Earlier testing could make it possible to begin treatment and support much sooner.
The researchers estimate that a blood test of this kind could take about five years to become available. Compared with brain scans and other Parkinson’s screening methods, however, a blood sample would be simple, fast, and easy to collect. It is also not the only Parkinson’s screening blood test currently being developed.
More than 10 million people worldwide are now affected by Parkinson’s, and there is still no cure. One of the best chances of changing that may lie in identifying the disease long before it becomes established.
“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,” said Danish Anwer, a systems biologist at Chalmers University of Technology.
“The study is an important step towards facilitating early identification of the disease and counteracting its progression before it has gone this far.”
Source
The research was published in npj Parkinson’s Disease
