Blood test identifies Parkinson's years before symptoms
Scientists have developed a blood-based test that detects Parkinson's disease up to seven years before the onset of symptoms. The test targets abnormal alpha-synuclein proteins and shows high accuracy in at-risk individuals. This breakthrough could enable earlier treatments to slow disease progression.
A new diagnostic tool for Parkinson's disease, detailed in a study published in The Lancet Neurology, offers hope for early intervention. Researchers at the Mayo Clinic analyzed blood samples from 22 individuals diagnosed with REM sleep behavior disorder (RBD), a condition that often precedes Parkinson's. Over a follow-up period from 2012 to 2023, the test accurately predicted which participants would develop Parkinson's symptoms.
The test employs a seed amplification assay to detect misfolded alpha-synuclein proteins, a hallmark of Parkinson's. In the study, it identified the protein in 10 of 11 RBD patients who later progressed to Parkinson's, achieving 93% sensitivity and 100% specificity. Lead author Dr. V. Shruthi Vaidya stated, "This assay provides a non-invasive way to identify people at high risk, potentially years before motor symptoms emerge."
RBD affects about 1% of the general population and up to 80% of those with RBD develop synucleinopathies like Parkinson's within 12 years. The study participants were monitored for an average of 9.5 years, with the test performed on baseline samples collected early in the disease process. No participants without progression tested positive, highlighting the test's precision.
This development builds on prior research identifying alpha-synuclein as a key biomarker. Previous tests required cerebrospinal fluid or skin biopsies, but this blood-based method is simpler and more accessible. The Mayo Clinic team, including neurologists and biochemists, emphasized that while promising, larger validation studies are needed before clinical use.
Early detection could transform Parkinson's management, where current treatments mainly address symptoms after diagnosis. With no cure, slowing progression through lifestyle or emerging therapies might preserve quality of life. The study was funded by the National Institutes of Health and involved collaboration with international experts.
Experts caution that RBD screening isn't routine yet, but this test could guide targeted monitoring for high-risk groups. As Dr. Vaidya noted, "Identifying Parkinson's early opens doors to preventive strategies we've long sought." The findings were presented at the International Congress of Parkinson's Disease and Movement Disorders in September 2024.