Salivary alpha-synuclein in the diagnosis of Parkinson's disease and Progressive Supranuclear Palsy

• Published in: Parkinsonism & related disorders Vol. 63; pp. 143 - 148
• Main Authors: Vivacqua, Giorgio, Suppa, Antonio, Mancinelli, Romina, Belvisi, Daniele, Fabbrini, Andrea, Costanzo, Matteo, Formica, Alessandra, Onori, Paolo, Fabbrini, Giovanni, Berardelli, Alfredo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2019
• Subjects: Aged; Alpha-synuclein; alpha-Synuclein - metabolism; Biomarkers; Biomarkers - metabolism; Cohort Studies; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Parkinson Disease - diagnosis; Parkinson Disease - metabolism; Parkinson's disease; Progressive Supranuclear Palsy; Saliva; Saliva - metabolism; Supranuclear Palsy, Progressive - diagnosis; Supranuclear Palsy, Progressive - metabolism; Parkinson's disease; HS; PSP; Progressive Supranuclear Palsy; PD; nLR; α-syn; pLR; Biomarkers; α-synolig; Saliva; Alpha-synuclein; α-syntotal
• ISSN: 1353-8020; 1873-5126; 1873-5126
• DOI: 10.1016/j.parkreldis.2019.02.014

Alpha-synuclein (α-syn) aggregation is the pathological hallmark of Parkinson's Disease (PD). In this study, we measured α-syn total (α-syntotal), oligomeric α-syn (α-synolig) and α-synolig/α-syntotal ratio in the saliva of patients affected by PD and in age and sex-matched healthy subjects. We also compared salivary α-syntotal measured in PD with those detected in Progressive Supranuclear Palsy (PSP), in order to assess whether salivary α-syn can be used as a biomarker for PD and for the differential diagnosis between PD and PSP. We studied 100 PD patients, 20 patients affected by PSP and 80 age- and sex-matched healthy subjects. ELISA analysis was performed using two commercial ELISA platforms and a specific ELISA assay for α-syn aggregates. We detected lower α-syntotal and higher α-synolig in PD than in healthy subjects. Conversely in PSP salivary α-syntotal concentration was comparable to that measured in healthy subjects. Receiver Operating Characteristic analyses revealed specific cut-off values able to differentiate PD patients from healthy subjects and PSP patients with high sensitivity and specificity. However, there was no significant correlation between clinical and molecular data. Salivary α-syn detection could be a promising and easily accessible biomarker for PD and for the differential diagnosis between PD and PSP. •Salivary α-syntotal (unaggregated) is reduced in PD patients but not in PSP patients.•Salivary α -synolig is higher in PD patients than in healthy subjects.•Salivary α-syntotal, α-synolig and α -synolig/α -syntotal ratio can distinguish PD patients from healthy subjects.•Salivary α-syntotal can distinguish PD patients from PSP patients.•Heterogeneity of α-syn aggregates ay determine the low sensitivity when differentiating PD patients from healthy subjects.