Fig. 3

High diagnostic accuracy of plasma amyloid and phosphorylated Tau 181 in the exploratory cohort according to A amyloid status, B clinical condition, and C progression to AD dementia. Receiver operating curve (ROC) analyses presented with the area under the curve (AUC) with 95% confidence interval (CI) for plasma Aβ42/40 ratio, p-Tau181, and p-Tau181/Aβ42 ratio. Amyloid status was determined according to reference values of CSF Aβ42/Aβ40 ratio for dichotomization into negative (n = 58) and positive (n = 80). Clinical condition was determined according to their probable clinical diagnosis, grouped as NC + MCI-Stable (n = 58) vs. MCI-AD + AD (n = 80). MCI progression was determined, dividing patients into those who remained cognitively stable (MCI-Stable; n = 36) and those that developed AD-dementia (MCI-AD; n = 36). Abbreviations: Aβ, amyloid beta; AD, Alzheimer’s disease; CSF, cerebrospinal fluid; MCI, mild cognitive impairments; p-Tau181, phosphorylated tau protein in the position 181