# [<sup>18</sup>F]RO948 Tau PET in early and late onset Alzheimer's disease: associations with plasma p-tau 217, atrophy and cognition

Article · Zapater-Fajari M, Bucci M, Chiotis K, Almkvist O, Wall A, Eriksson J, Antoni G, Pola I, Tan K, Traichel W, Benedet AL, Ashton NJ, Zetterberg H, Bogdanovic N, Nordberg A

- Archive id: doi:10.1007/s00259-026-08015-w
- Published: 2026-06-26
- Venue: European journal of nuclear medicine and molecular imaging
- DOI: https://doi.org/10.1007/s00259-026-08015-w
- PMID: 42360329
- PMCID: PMC13633377
- Citations: 0
- Source URL: https://doi.org/10.1007/s00259-026-08015-w
- PDF: https://europepmc.org/articles/PMC13633377/pdf
- Provenance: europepmc

## Abstract

Purpose The aim of this study was to compare regional brain tau extent across the disease spectrum in early- and late-onset Alzheimer's disease using the second-generation tau PET tracer \[ 18 F\]RO948, and to investigate the relationship between PET-derived patterns, plasma p-tau217, brain atrophy, and cognition. Methods We examined 57 participants: 39 patients from the Cognitive Assessment Unit at Karolinska University Hospital (Stockholm/Sweden)-diagnosed as MCI Aβ- (n = 10), MCI Aβ + (n = 16; 8 EO and 6 LO), and AD (n = 13; 5 EOAD and 8 LOAD)-and 18 cognitively normal controls. All participants underwent \[ 18 F\]RO948 tau-PET, structural MRI, cognitive testing, and plasma p-tau217 analysis. Results Both EO and LO MCI (Aß +) showed higher \[ 18 F\]RO948 binding in amygdala, entorhinal cortex, hippocampus (p \< 0.001) and extending to inferior temporal regions (p \< 0.01) compared to controls, with some MCI-EO cases already showing advanced neocortical tau burden. At the AD stage, EOAD patients showed greater neocortical tau extent in temporo-parietal and frontal cortices than LOAD. P‑tau217 positively correlated with \[ 18 F\]RO948 in amygdala, entorhinal cortex, hippocampus (rho = 0.81) followed by temporal (rho = 0.71), and parietal cortices (rho = 0.56, all p \< 0.001). The Tau‑PET/p-tau217 association was different between EOAD and LOAD with greater differences in parietal cortices. Tau‑PET also showed stronger region‑specific associations with cognitive impairment than p‑tau217, especially in EOAD. Conclusions \[ 18 F\]RO948-PET captured interindividual heterogeneity in tau accumulation that was not reflected by plasma p-tau217. This dissociation was particularly evident in neocortical regions, where LOAD showed elevated plasma p-tau217 levels despite low tau PET binding. These findings highlight the value of tau-PET as a sensitive biomarker for detecting early disease heterogeneity, assessing disease severity, and improving patient stratification for disease-modifying treatments.

_Abstract reproduced under CC-BY (article license as recorded by Europe PMC; abstract reproduced unmodified apart from markup removal)._

Topics: [Alzheimer's, Parkinson's & Neurodegeneration](https://space-kitty.com/topics/neurodegeneration)

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