P4-476: EFFECT OF PATIENT-SPECIFIC PRE-ANALYTIC VARIABLES ON CSF Aβ42 CONCENTRATIONS MEASURED ON AN AUTOMATED CHEMILUMINESCENT PLATFORM

Cerebrospinal fluid (CSF) biomarker concentrations are valuable in the diagnosis of Alzheimer's Disease (AD). CSF β-amyloid 1–42 (Aβ42), is a core biomarker of AD. While analytic variability has been reduced with the advent of automated assays, pre-analytical variability has limited clinical use. The main purpose of this study was to evaluate the effect of patient-specific pre-analytical variables (fasting, inadvertent blood contamination, CSF...