Researchers from Beth Israel Deaconess Medical Center have discovered that an important clue to diagnosing Parkinson's disease (PD) may lie just beneath the skin. In a study published online in Neurology, they report that elevated levels of a protein called alpha-synuclein can be detected in the skin of Parkinson's patients. This offers a possible biomarker to enable clinicians to identify and diagnose PD before the disease has reached an advanced stage.
Alpha-synuclein is a protein found throughout the nervous system. It is the primary component of protein clumps known as Lewy bodies, which are considered the hallmark of Parkinson's disease. There is accumulating evidence that the protein plays a role in Parkinson's disease development.
“Skin-related autonomic manifestations, including excessive and diminished sweating and changes in skin color and temperature, occur in almost two-thirds of patients with Parkinson's disease,” says senior author Roy Freeman, MD. “The skin can provide an accessible window to the nervous system, and based on these clinical observations we decided to test whether examination of the nerves in a skin biopsy could be used to identify a PD biomarker.”
To test this hypothesis, the research team enrolled 20 patients with Parkinson's disease and 14 control subjects of similar age and gender. The participants underwent examinations, autonomic testing, and skin biopsies in three locations on the leg. Alpha-synuclein deposition and density of cutaneous sensory, sudomotor, and pilomotor nerve fibers were measured. Alpha-synuclein was increased in the cutaneous nerves supplying the sweat glands and pilomotor muscles in the Parkinson's patients. Read the study abstract.