Apolipoprotein E in Cerebrospinal Fluid: Relation to Phenotype and Plasma Apolipoprotein E Concentrations

the development of Alzheimer disease, but data on apoE in cerebrospinal fluid (CSF) are limited. The aim of the present study was to measure apoE in CSF and relate its concentrations to apoE phenotype and CSF lipids. Methods: We adapted an assay for CSF apoE sensitivity using an ELISA. It allowed us to measure CSF apoE with sufficient reproducibility and precision. Results: The within- and between-run CVs were <7%, and the detection limit was 0.025 mg/L. No cross-reac-tion was found for other apolipoproteins. No significant differences related to sex or apoE phenotype were ob-served in the CSF apoE concentration. The mean CSF apoE concentration was significantly higher in the 0–5 year group (n 5 6; 18.47 6 1.14 mg/L, mean 6 SD) than in the>5 year group (n 5 34; 8.82 6 3.31 mg/L). Th