Fig. 6

Correlations between CSF Aβ values and plasma Aβ measurements by three different assays. The cerebrospinal fluid (CSF) concentrations of Aβ40 (A, B, C), Aβ42 (D, E, F) and the CSF Aβ42/Aβ40 ratio (G, H, I) are plotted against the corresponding plasma values measured with Elecsys in plasma (A, D, G), Elecsys in IP-eluates (B, E, H) and MSD in IP-eluates (C, F, I). Spearman correlation coefficients and p-values are indicated. Data points are colored by diagnostic group (red = Aβ+, blue = Aβ−). Aβ, amyloid-β; Aβ+, Aβ-positive: CSF Aβ42/40 ≤ 0.050; Aβ−, Aβ-negative: CSF Aβ42/40 > 0.050; IP, immunoprecipitation; MSD, Meso Scale Discovery V-PLEX Aβ panel 1 (6E10) assay kit