Key points:
- A new minimally invasive skin biopsy test can accurately detect a biomarker for Parkinson’s disease and related neurodegenerative disorders.
- Tested accuracy ranged from 93 to 100% for those with clinically confirmed neurodegenerative disorders.
- Just over 3% of control participants tested positive, possibly indicating the test could work as an early detector as well.
Neurologists have shown that a minimally invasive skin biopsy test can detect an abnormal form of alpha-synuclein, the pathological hallmark of Parkinson’s disease and the subgroup of neurodegenerative disorders known as synucleinopathies, at high positivity rates.
In this investigation, titled the Synuclein-One Study, researchers at 30 academic and community-based neurology practices worked with 428 people ages 40 to 99 years, with a clinical diagnosis of one of the four synucleinopathies—Parkinson’s disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and pure autonomic failure (PAF). While the four diseases do not respons to the same therapies, they do share some overlapping clinical feature and are all are characterized by the presence of the abnormal phosphorylated α-synuclein (P-SYN).
Participants, including controls, underwent three 3-millimeter skin punch biopsies taken from the neck, the knee, and the ankle.
Among the participants with clinically confirmed PD, 93% demonstrated a positive skin biopsy for P-SYN. Participants with DLB and MSA tested 96% and 98% positive, respectively. One hundred percent of participants with PAF were positive for the abnormal protein.
“These are systemic disorders that impact the peripheral and central nervous systems in profound ways,” said senior author Roy Freeman, MD, director of the Center for Autonomic and Peripheral Nerve Disorders at BIDMC and professor of neurology at Harvard Medical School. “While we have been aware of the presence of alpha-synuclein in cutaneous nerves for many years, we were thrilled with the accuracy of this diagnostic test.”
Among the controls, just over 3% tested positive for P-SYN—an error rate the authors suspect may indicate some of the healthy controls are at risk for a synucleinopathy.
“Parkinson’s disease and its subgroup of progressive neurodegenerative diseases show gradual progression, but alpha-synuclein is present in the skin even at the earliest stages,” noted Freeman.
The authors anticipate that this research will play a role in accelerating drug development for synucleinopathies.
“Enrolling the right patients in clinical trials for these complex diseases is of utmost importance,” said Freeman. “Identifying the relevant biomarker in a patient and tracking it over the course of a clinical trial is an essential component of drug development in the neurodegeneration field.”