Longitudinally, all mean (SD) biomarker levels increased in the EOAD group (p-tau217: 0.253 [0.077] pg/mL, P = .001; GFAP: 0.173 [0.040] pg/mL, P < .001; NfL: 0.149 [0.045] pg/mL, P = .001), whereas in the FTD group, only NfL level showed an upward pattern (0.251 [0.127] pg/mL, P = .05). Here, GFAP is linked to frontotemporal dementia.