The Diagnostic Value of CSF Amyloid-β43 in Differentiation of Dementia Syndromes

Kim   A.   Bruggink; H.   Bea   Kuiperij; Jurgen   A.H.R.   Claassen; Marcel   M.   Verbeek

Abstract

Amyloid-β (Aβ) is known as the most prominent core protein in Alzheimer’s Disease (AD) senile plaques. Although research has focused mainly on Aβ₄₀ and Aβ₄₂ as potential cerebrospinal fluid (CSF) biomarkers, a range of Aβ peptides with variable lengths has been demonstrated in the brains and CSF of AD patients. Recently, it has been found that the Aβ₄₃ peptide may be more abundant than previously assumed, could therefore play an important role in AD pathophysiology, and hence also function as putative biomarker. In this study the value of CSF Aβ₄₃ in AD diagnosis was investigated. Aβ₄₃ levels in CSF were highly correlated with Aβ₄₂ levels. Furthermore, in differentiation of AD from nondemented controls and from patients with Lewy body dementia and frontotemporal dementia, Aβ₄₃ had an equal diagnostic value as Aβ₄₂, both as a single biomarker and in combination with total and phosphorylated tau. In conclusion, quantification of Aβ₄₃ in CSF does not add novel diagnostic information to the differential diagnosis of AD compared to existing biomarkers.

Keywords: Aβ₄₃, Alzheimer’s disease, Amyloid-β, biomarker, cerebrospinal fluid, dementia with lewy bodies, ELISA, frontotemporal dementia.