Fig. 2

Plasma Aβ42, NT1 tau, and NfL change differentially with age in Down syndrome versus control subjects. Plasma samples from 100 individuals with DS and 100 controls matched for age and sex were analyzed with ultra-sensitive assays for a, d Aβ42, b, e NT1 tau, and c, f NfL. a–c Individual Aβ42, NT1 tau, and NfL values of subjects with DS (blue) and controls (red) are shown as a function of age. Each point represents one individual. d–f Data displayed in a–c are grouped in 10 year intervals. Each open circle represents a single individual. Mean and standard error of the mean are shown. a, d At any given age, the absolute amount of Aβ42 is higher in DS than in control subjects, but levels of Aβ42 decrease with age, with a greater decrease in DS. b, e NT1 tau levels tend to increase in older individuals with DS compared to controls. c, f NfL levels show a greater increase with age in individuals with DS than controls. Differences were assessed with paired t test (normally distributed data) or Wilcoxon signed-rank test (non-normally distributed data). p values were adjusted for multiple testing using Bonferroni correction. *p < 0.05; **p < 0.01; ***p < 0.001