Presence of Phosphorylated Tau Protein in the Skin of Alzheimer´s Disease Patients

Abstract

Background: The presence of misfolded proteins in the brain is the hallmark of neurodegenerative diseases. Protein aggregates could have systemic expression and might be found in several tissues including the skin.\rObjective: To demonstrate the presence of phosphorylated Tau (p-Tau) in the skin cells of patients with Alzheimer´s Disease (AD). Material and methods: Antibodies against p-Tau (PHF, phosphorylated at S296 and AT8, phosphorylated at S202) were assayed in biopsied tissue from the retro-auricular area in 49.\rsubjects: 20 with AD, 12 with nondegenerative dementia and 17 age-matched controls. Light and confocal microscopies were employed to localize Tau protein by immunohistochemistry and their presence in the skin was confirmed through Western blots.\rResults: The skin biopsy taken from AD patients presented significantly higher levels of p-Tau (AT8: hyperphosphorylated at Ser 202) when compared both to control subjects and patients with non-degenerative dementia (p<0.001).\rConclusion: This study demonstrates the presence of p-Tau in skin biopsies by immunoreactivity. This procedure could be used to support the clinical diagnosis of AD in living patients.