Alzheimer biomarker P‑tau 217 shows limited predictive power in preclinical stage

A study led by Prof. Klaus Gerwert of the ProDi group at Ruhr‑Universität Bochum analyzed blood samples from 779 participants of the population‑based ESTHER cohort, collected over 17 years by the Deutsches Krebsforschungszentrum (DKFZ). The research compared the performance of leading blood‑based biomarkers for Alzheimer’s disease across the disease continuum.

P‑tau 217 demonstrated excellent diagnostic accuracy once Alzheimer’s disease reached the clinical stage (AUC comparable to CSF Aβ42/40 ratio and amyloid‑PET). However, in symptom‑free individuals its predictive power was only moderate (AUC = 0.67). In contrast, a biomarker reflecting amyloid‑β protein misfolding showed higher predictive ability in the preclinical phase (AUC = 0.79). Combining this misfolding marker with demographic, genetic, and additional blood biomarkers yielded a panel with a very high AUC of 0.87, suggesting it could forecast a later Alzheimer’s diagnosis many years before symptoms appear.