Skin Test May Allow Earlier Diagnosis of Alzheimer, Parkinson Diseases

A skin test used to detect elevated levels of abnormal proteins may allow earlier diagnosis of Alzheimer and Parkinson diseases, according to a new study.

“Until now, pathological confirmation was not possible without a brain biopsy, so these diseases often go unrecognized until after the disease has progressed,” said lead author Ildefonso Rodriguez-Leyva, MD, of Central Hospital at the University of San Luis Potosi in San Luis Potosi, Mexico.

“We hypothesized that since skin has the same origin as brain tissue while in the embryo that they might also show the same abnormal proteins. This new test offers a potential biomarker that may allow doctors to identify and diagnose these diseases earlier on.” Alzheimer disease and Parkinson disease are the two most frequent neurodegenerative disorders.

For the study, researchers took skin biopsies from 20 patients with Alzheimer disease, 16 with Parkinson disease, and 17 with dementia caused by other conditions and compared them to 12 age-matched healthy volunteers. They measured reactivity to antibodies phosphorylated Tau (p-Tau) and alpha-synuclein (α-synuclein) both in sections of paraffin embedded tissue and in proteins extracted from tissue homogenates.

As compared to healthy patients and ones with dementia caused by other conditions, those with both Alzheimer and Parkinson disease had 7 times higher levels of the tau protein. Patients with Parkinson disease also had an 8 times higher level of the α-synuclein protein than the control group.

In conclusion, Dr Rodriguez-Leyva said “This study demonstrates the presence of p-Tau and α-synuclein in skin biopsies by immunoreactivity.”

The presence of misfolded proteins is the hallmark of neurodegeneration, which is currently demonstrated through the analysis of brain tissue obtained postmortem. “More research is needed to confirm these results, but the findings are exciting because we could potentially begin to use skin biopsies from living patients to study and learn more about these diseases. This also means tissue will be much more readily available for scientists to study,” said Rodriguez-Leyva. “This procedure could be used to study not only Alzheimer’s disease and Parkinson’s disease, but also other neurodegenerative diseases.”

The researchers will present their results on Wednesday, April 22 (S33-006) at the American Academy of Neurology’s 67th Annual Meeting in Washington, DC, April 18 to 25, 2015.

Abstract Title: Skin Cells Express Altered Proteins that Characterize the Most Common Neurodegenerative Diseases