Abstract
INTRODUCTION The development of fully automated immunoassay platforms has improved the technical reliability of cerebrospinal fluid (CSF) biomarkers for Alzheimer’s disease.
METHODS We quantified Aβ1-42, Aβ1-40, tTau and pTau levels using the Lumipulse G System in 94 CSF samples from participants of the SPIN cohort with available 18F-Florbetapir imaging. Amyloid scans were assessed visually and through automated quantification. We determined the cutoffs of CSF biomarkers that optimized their agreement with 18F-Florbetapir PET and evaluated concordance between markers of the amyloid category.
RESULTS Aβ1-42, tTau and pTau (but not Aβ1-40) and the ratios with Aβ1-42 had good diagnostic agreement with 18F-Florbetapir PET. As a marker of amyloid pathology, the Aβ1-42/Aβ1-40 ratio had higher agreement and better correlation with amyloid PET than Aβ1-42 alone.
DISCUSSION CSF biomarkers measured with the Lumipulse G System show good agreement with amyloid imaging. Combination of Aβ1-42 with Aβ1-40 increases the agreement between markers of amyloid pathology.
