Tauopathies and synucleinopathies: do cerebrospinal fluid beta-amyloid peptides reflect disease-specific pathogenesis?

To evaluate variations in amyloid beta (Abeta) peptide pattern in cerebrospinal fluid (CSF) in neurodegenerative disorders. A recently established quantitative urea-based Abeta-sodium-dodecylsulfate-polyacrylamide-gel-electrophoresis with western immunoblot (Abeta-SDS-PAGE/immunoblot) revealed a highly conserved Abeta peptide (Abeta1-37, 1-38, 1-39, 1-40, 1-42) pattern in CSF. We asked whether the variation might be useful to further elucidate the overlap between or distinctions among neurodegenerative diseases in Abeta-processing. We used the Abeta-SDS-PAGE/immunoblot to investigate CSF for disease-specific Abeta peptide patterns. CSF samples from 96 patients with mainly clinically diagnosed Alzheimer's disease (n = 15), progressive supranuclear palsy (n = 20), corticobasal degeneration (n = 12), Parkinson's disease (n = 11), multiple systems atrophy (n = 18), and dementia with Lewy-bodies (n = 20) were analysed as well a comparison group (n = 19). The Abeta peptide patterns varied between tauopathies and synucleinopathies and between all diseases and the comparison group, possibly due to the influence of tau and alpha-synuclein on Abeta-processing.