Blood test predicts how fast Parkinson’s will progress

Researchers at Erasmus University Medical Center have identified a blood-based biomarker that can predict the progression rate of Parkinson's disease. The biomarker, a measurable indicator of the condition, is associated with defects in DNA repair pathways, which correlated with faster progression of motor symptoms over a 36-month period. Patients with more severe disease progression showed significant transcriptome changes linked to genome instability, suggesting this biomarker could stratify Parkinson's patients and inform clinical trials targeting this aging-related mechanism.

Parkinson's disease (PD) is a progressive movement disorder of the nervous system that worsens over time. It primarily affects dopaminergic neurons in the nigrostriatal circuits of the brain. The symptoms, which typically start gradually, include tremors, slowed movement (bradykinesia), rigid muscles, impaired posture and balance, loss of automatic movements, changes in speech, and alterations in writing. Nonmotor symptoms such as depression, anxiety, sleep disturbances, and cognitive issues can also occur. While there is no cure for Parkinson's disease, treatments are available to help manage symptoms.

Aging is the primary risk factor for Parkinson's disease, and the accumulation of DNA damage is a key characteristic of aging. Parkinson's patients often exhibit reduced DNA repair mechanisms compared to healthy individuals of the same age. This link between DNA damage and Parkinson's is critical, as the progressive accumulation of damage in nuclear DNA is considered a fundamental cause of age-related functional decline and diseases.

Erasmus MC's Breakthrough Discovery

The Erasmus MC team analyzed a large patient database from the Michael J. Fox Foundation and found that patients with certain DNA repair defects experienced more severe Parkinson's symptoms after three years. Lead researcher Pier Mastroberardino emphasized that predicting the course of Parkinson's could provide certainty for both patients and doctors, enabling more targeted treatment plans.

The study analyzed longitudinal expression data from blood samples collected from 484 Parkinson's disease patients and 187 healthy controls. The researchers examined these participants at an initial visit and again after 36 months. The analysis revealed that patients with Parkinson's disease showed dysregulation of pathways involved in RNA processing, transcription, and translation compared with healthy controls. Notably, downregulation of DNA repair processes was observed at the initial visit, particularly among patients who later exhibited more severe motor symptom deterioration over the 36-month observation period.

The potential for targeted treatment

The discovery of this biomarker could revolutionize the management of Parkinson's disease. Currently, the standard treatment involves replacing dopamine, a neurotransmitter, but this can lead to side effects like dyskinesia. By predicting disease progression, doctors can make more informed decisions about when and how to administer dopamine, minimizing potential side effects. Mastroberardino notes that knowing how severe the disease will be in three years allows for much more targeted treatment planning. Theoretically, a blood test at a patient's first visit could predict the course of their Parkinson's disease.