Fig. 3

Antibody-peptide binding profiles are able to predict chronological age with high accuracy. a While the average N-di-serine probe intensity (y-axis) is highly associated with age (x-axis), the average normalized fluorescent intensity of age-associated N-di-serine probes is only moderately predictive for chronological age (Pearson’s r = 0.36). b An elastic net regression model of peptide array probe intensity data is able to predict chronological age with high accuracy on holdout examples during model training. Each data point is a single donor, showing the age of donor (x-axis) and prediction of age based on regression model of antibody binding profile (y-axis). Pearson’s correlation coefficient of r = 0.75. c The model learned from the Training Cohort is applied to the Verification Cohort. Pearson’s correlation coefficient is r = 0.74 (p < 10^− 181, 95% confidence interval of [0.71, 0.76]). d The age regression residuals (y-axis) for 24 Donors (x-axis) are highly reproducible. Each donor was assayed in 16 technical replicates, which were balanced across multiple days, array manufacturing synthesis lots, secondary antibody reagent lots, and sample dilution aliquots (Methods). Each data point is a single assay for a single donor. e The age regression residual values (y-axis) are consistent across N = 16 donors that consented to regular blood draws for > 1 yr. Donors with > 5 samples over > 1 yr (N = 13) had consistent age-regression values over this time period. Data shown for all donors (lines, color indicates donor)