Alain Kaelin-Lang, Switzerland
Ente Ospedaliero Cantonale (EOC) Neurology DepartmentAuthor Of 1 Presentation
TAU PROTEIN CHARACTERISATION IN SKIN BIOPSIES DIFFERENTIATES PATIENTS WITH SYNUCLEINOPATHIES AND TAUOPATHIES
Abstract
Aims
The microtubule-associated protein tau is strongly involved in many neurodegenerative disorders. Even though abnormal accumulation of tau is a characteristic feature of tauopathies, modified tau has been observed also in alpha-synucleinopathies like Parkinson's Disease (PD) and Multiple System Atrophy (MSA). Due to the common involvement of peripheral nervous system (PNS) in several neurodegenerative diseases, in this study we characterized tau expression in the skin PNS of patients with PD, MSA, tauopathies and healthy subjects (HC) as a possible biomarker of disease.
Methods
We recruited 27 patients with idiopathic PD, 8 MSA, 10 atypical parkinsonisms with possible tauopathies (AP-Tau) and 20 HC. A double 3mm punch skin biopsy was performed at two anatomical sites (cervical and ankle). We evaluated the expression of physiological and phosphorylated tau by immunofluorescence assays and western blot and quantified tau expression by ELISA.
Results
Physiological tau was abundantly expressed in skin somatosensory and autonomic nerve fibers. Western-blot analysis revealed the presence of two different tau isoforms (~70 and 55 KDa) and a different pattern of phosphorylation between synucleinopathies and tauopathies patients. ELISA assay showed higher levels of tau in AP-Tau compared to other groups. Finally, ROC curves analysis displayed an optimal diagnostic performance for AP-Tau patients especially compared to PD (sensitivity 90%, specificity 69%) and MSA (sensitivity 90%, specificity 86%).
Conclusions
Characterisation of tau in skin peripheral nervous system shows a differential expression of the protein between groups and suggests that tau profiling in skin biopsy is a promising biomarker to discriminate neurodegenerative diseases.