Researchers from Iowa State University have developed a simple skin test that can accurately detect Parkinson’s disease. Parkinson’s disease is typically only definitively diagnosed at autopsy, with misdiagnosis common early on in the condition, which complicates finding potential treatments. Researchers now say that the skin test makes early detection of Parkinson’s disease possible for the first time, and promises better clinical trials.
The research uses a method called real-time quaking induced conversion assay (or RT-QuIC for short), which was originally devised to diagnose mad cow disease. Scientists have spent years tweaking the test, so it can detect misfolded alpha-synuclein proteins: the signature sign of Parkinson’s disease. These proteins accumulate in the brain, which leads to neuronal damage. Researchers have also discovered that the proteins build up in other body tissues, including the skin. “Parkinson’s disease is definitively diagnosed only on autopsy when alpha-synuclein clumps are observed in the brain,” explains Svjetlana Miocinovic, assistant professor in the department of neurology at Emory University School of Medicine. “We don’t know what causes alpha-synuclein to clump, but when it does, it leads to neuronal dysfunction and death, eventually leading to signs and symptoms of Parkinson’s disease.”
To develop the skin test, researchers conducted a blind study of 50 skin samples (half from patients with Parkinson’s disease, and half from people without neurological disease). The protein assay successfully diagnosed 24/25 Parkinson’s disease patients, and protein clumping was found in only 1/25 controls. “The clinical diagnostic accuracy for early-stage PD has been quite poor, only around 50-70%,” says Dr. Thomas Beach, MD, a co-investigator of the study. “And since clinical trials really need to be done at an early stage to avoid further brain damage, they have been critically hampered because they have been including large percentages of people who may not actually have the disease. Improving clinical diagnostic accuracy is, in my view, the very first thing we need to do in order to find new useful treatments for PD.”
Importance of skin health
Science also shows skin health indirectly plays an important role in preventing Parkinson’s disease. Specifically, Vitamin C and Vitamin E — two fat-soluble vitamins essential for healthy and vibrant skin — have now been found to decrease Parkinson’s risk, a new study in Neurology finds. Researchers looked at the health records of over 43,000 adults from 1997-2016 to determine whether a high baseline of dietary antioxidants and total non-enzymatic antioxidant capacity (NEAC) are associated with the risk for Parkinson disease. 465 cases of Parkinson disease were recorded after 17 years. Individuals with the highest intakes of vitamins C and E were inversely associated with the risk for Parkinson disease. Consequently, eating foods high in vitamins E and C might help prevent the development of Parkinson’s disease later in life.
Ultimately, researchers say that the results of the study look promising. Testing skin samples may allow for earlier detection of Parkinson’s disease, which means physicians can test therapeutic strategies to slow or prevent the condition from worsening.