Fig. 1From: Performance of a fully-automated Lumipulse plasma phospho-tau181 assay for Alzheimer’s diseasePlasma p-tau181 distinguishes Aβ− CU from Aβ+ AD. A Plasma p-tau181 was highest in AD (n = 78) followed by MCI (n = 107) and CU (n = 463) groups. B Plasma p-tau181 was higher in groups with increasing copy number of the APOE ε4 allele in CU and MCI. C Classification of participants by amyloid-positivity revealed plasma p-tau181 was elevated in Aβ+ CU and Aβ+ MCI as well as in Aβ+ AD. D ROC curve analysis of p-tau181 in distinguishing AD cases from Aβ− CU controls. E The Youden method was used to determine optimal cutpoint maximizing sensitivity and specificity for distinguishing Aβ+ AD cases from Aβ− CU. Log10-transformed plasma p-tau 181 data analyzed using ANCOVA with age and sex included as cofactors. Tukey’s post hoc test was used for pairwise comparisons (A–C). Data presented as mean ± SDBack to article page