Diagnostic Fluid Biomarkers in Alzheimer’s Disease: Blood and Cerebrospinal Fluid

Background: Potential biomarkers for Alzheimer’s disease (AD) include amyloid β1-42 (Aβ1-42), t-Tau, p-Tau 181 , neurofilament light chain (NFL), and neuroimaging, but the feasibility of using these for the diagnosis and monitoring of AD has not been reported. Therefore, further development of these biomarkers is essential.Methods: We measured NFL and Aβ1-42 concentrations in CSF and plasma samples from 136 participants and performed correlation analysis to evaluate the utility of these biomarkers for early diagnosis and monitoring of disease progression in AD spectrum.Results: With disease progression, concentrations of NFL increased, and those of Aβ1-42 were decreases. The plasma and CSF values of NFL/Aβ1-42 were strongly correlated (r = 0.558). In addition, the plasma value of NFL/Aβ1-42 was strong correlated with hippocampal volume/ICV ( r = 0.409). In the early stage of AD, the plasma_NFL/Aβ1-42 was associated with higher diagnostic accuracy than were the individual biomarkers. Moreover, in preclinical AD, plasma_NFL/Aβ1-42 changed more rapidly than did either the t-Tau or the p-Tau181 values measured in the CSF.Conclusions: Taken together, our findings highlight the utility of plasma_NFL/Aβ1-42 as a biomarker for early diagnosis and monitoring of disease progression in AD spectrum.