CSF amyloid proteins
sAPPα/β concentrations were measured in CSF with a duplex immunoassay and electrochemiluminescence detection (Meso Scale Discovery, Rockville, MD, USA). CSF Aβ38, Aβ40, and Aβ42 concentrations were measured using a triplex immunoassay with electrochemiluminescence detection (Meso Scale Discovery, Rockville, MD, USA). The measurements were performed in one round of experiments using one batch of reagents by board-certified laboratory technicians blinded to clinical data. Intra-assay coefficients of variation were below 10%.