Derivation of cutoffs for the Elecsys^® amyloid β (1-42) assay in Alzheimer's disease.

ABSTRACT:

Introduction

An Elecsys® Amyloid β (Aβ [1-42]) immunoassay cutoff for classification of patients with Alzheimer's disease was investigated.

Methods

Cerebrospinal fluid samples collected from patients with mild-to-moderate Alzheimer's disease were analyzed by Elecsys® immunoassays: (1) Aβ (1-42), (2) total tau, and (3) phosphorylated tau. Cutoffs (Aβ [1-42] and ratios with tau) were estimated by method comparison between AlzBio3 (n = 206), mixture modeling (n = 216), and concordance with florbetapir F 18 imaging-based classification (n = 75).

Results

A 1065-pg/mL (95% confidence interval: 985-1153) Elecsys® Aβ (1-42) cutoff provided 94% overall percentage agreement with AlzBio3. Comparable cutoff estimates (95% confidence interval) were derived fro

SUBMITTER: Shaw LM 

PROVIDER: S-EPMC6222032 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature