Currently, there is no easy and reliable test available for the early diagnosis of Parkinson’s disease. Doctors need to carefully weigh symptoms, family history, and other factors to conclude.
A new study by Iowa State University has shown a simple skin test can accurately identify Parkinson’s disease, demonstrating the feasibility of the method for the first time. Scientists have shown how a chemical assay can detect the protein alpha-synuclein clumping in skin samples to help diagnose Parkinson’s disease (PD).
The research centers on a real-time quaking-induced conversion assay method, an originally developed test to detect mad cow disease. Scientists have spent several years optimizing the assay for detecting misfolded proteins in similar human and animal disorders.
The study was conducted on 50 skin samples provided by the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND)/Brain and Body Donation Program based at Banner Sun Health Research Institute. Half of the samples came from patients with Parkinson’s disease.
Scientists used protein assay to diagnose 24/25 Parkinson’s disease patients correctly, and only 1/25 controls had the protein clumping.
Dr. Charles Adler, M.D., professor of neurology at Mayo Clinic Arizona, a co-investigator of the study, notes that “these results indicate tremendously high sensitivity and specificity, which is critical for a diagnostic test.”
Dr. Thomas Beach, MD, a co-investigator of the study and head of the Civin Laboratory at Banner Sun Health Research Institute, said, “The clinical diagnostic accuracy for early-stage PD has been quite poor, only around 50-70%. And since clinical trials need to be done at an early stage to avoid further brain damage, they have been critically hampered because they have included large percentages of people who may not have the disease. Improving clinical diagnostic accuracy is, in my view, the very first thing we need to do to find new useful treatments for PD.”
Parkinson’s disease arises from misfolded alpha-synuclein proteins that accumulate in the brain leading to neuronal damage. These misfolded alpha-synuclein proteins also collect in other body tissues as well, including the skin.
Kanthasamy said, “Testing skin samples could lead to earlier detection of Parkinson’s disease. Earlier diagnosis could allow physicians to test therapeutic strategies designed to slow or prevent the development of advanced symptoms.”
The study is published in the scientific journal Movement Disorders.