Fig. 4

Correlations between Aβ measures in CSF and plasma. No statistically significant correlations observed between a CSF Aβ1–42 and plasma Aβ42 or b CSF Aβ1–40 and plasma Aβ40. c Aβ1–42/Aβ1–40 ratio in CSF statistically significantly correlated with plasma Aβ42/Aβ40 ratio. Scatterplots of indicated Aβ variables in blood plasma and CSF are shown. Pearson correlation coefficients annotated and Deming regressions shown as dashed lines. Statistical tests were done after log transformation. Accordingly, scaling of x and y axes is logarithmic. Aβ amyloid beta, CSF cerebrospinal fluid, IP immunoprecipitation