A unique feature of the HBTRC dataset is the availability of tissue samples from different brain regions from the same individual. All biomarkers in PFC were tested for coherence in visual cortex (VC) and cerebellum (CR). We confirmed that BioAge and the disease-specific biomarkers were also expressed coherently and differentially between normal and AD samples. We then performed direct correlation analysis between the biomarker scores in these regions. BioAge demonstrated relatively high correlations of 0.81 between VC1 and PFC1, with residual differences possibly reflecting different levels of aging between the brain regions. The Lipa biomarker also demonstrated high correlation of 0.80 between these regions. We determined that correlation between Inflame scores in PFC1 and VC1 was equal to 0.83. The highest correlation of 0.93 between PFC1 and VC1 was observed in the NdStress biomarker. These results are also shown in Figure 5, whereas similar observations for PFC1 and CR1 are shown in Figure S5. This exceptionally high level of correlation between the regions is likely explained by the systemic nature of inflammation and metabolic regulation that span diverse brain regions.
