- The study compared PET and plasma-based temporal modeling of amyloid and tau biomarkers in Alzheimer's disease.
- Longitudinal data from ADNI and Penn ADRC were used, including amyloid PET, tau-PET, and plasma p-tau217.
- The sampled-iterative Local approximation (SILA) method was employed to generate biomarker trajectory models.
- Plasma and PET models showed similar results for amyloid and tau onset, with stronger agreement for tau onset.
- Accuracy of estimated onset was high within modality but slightly less accurate when comparing across modalities.
- Earlier tau onset was associated with younger amyloid onset, female sex, and ≥1 ApoE ε4 allele.
- Earlier dementia onset after tau was linked to later tau onset for both plasma and PET models.
- Male sex was associated with a shorter tau to dementia gap in plasma models.
- Plasma biomarker modeling provides comparable information to PET, especially for tau onset age.
- Plasma biomarkers can serve as a widely accessible tool for assessing biological disease severity.