Next, we compared the cell proportion of LOAD vs ADAD and found that the cell composition differs between them. We first selected the LOAD brains (n = 25) to match the Braak staging distribution of ADAD brains (n = 17). The ADAD brains showed a significant lower relative neuronal proportion compared to LOAD brains (β = − 0.08; p = 1.03 × 10−02; Table 3) and an increased relative astrocyte proportion (β = 0.11; p = 9.26 × 10−04; Table 3). Then, we analyzed the entire Knight-ADRC LOAD brains, by extending the model to correct for Braak stages. We also observed significant lower relative neuronal proportion (β = − 0.09; p = 4.71 × 10−03; Table 3; Fig. 3a; Additional file 1: Table S9) and increased relative astrocyte proportion (β = 0.11; p = 5.24 × 10−04; Table 3; Fig. 3a; Additional file 1: Table S9) in ADAD brains compared to LOAD. We observed the same cellular differences when we corrected for CDR at death (β = − 0.12; p = 2.11 × 10−03 for neurons and β = 0.13;
