The Diagnostic Value of CSF Amyloid-beta43 in Differentiation of Dementia Syndromes

Abstract

Amyloid-beta (Abeta) is known as the most prominent core protein in Alzheimer's Disease (AD) senile plaques. Although research has focused mainly on Abeta40 and Abeta42 as potential cerebrospinal fluid (CSF) biomarkers, a range of Abeta peptides with variable lengths has been demonstrated in the brains and CSF of AD patients. Recently, it has been found that the Abeta43 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 Abeta43 in AD diagnosis was investigated. Abeta43 levels in CSF were highly correlated with Abeta42 levels. Furthermore, in differentiation of AD from nondemented controls and from patients with Lewy body dementia and frontotemporal dementia, Abeta43 had an equal diagnostic value as Abeta42, both as a single biomarker and in combination with total and phosphorylated tau. In conclusion, quantification of Abeta43 in CSF does not add novel diagnostic information to the differential diagnosis of AD compared to existing biomarkers.