Temporal T807 binding correlates with CSF tau and phospho-tau in normal elderly

ABSTRACT

Objective: To better understand cross-sectional relationships between CSF and PET measures of tau pathology, we compared regional and global measures of ¹⁸F-T807 (AV-1451) PET to CSF protein levels of total tau (t-tau), phosphorylated tau (p-tau), and β-amyloid 1–42 (Aβ42).

Methods: T-tau, p-tau, and Aβ42 levels were assessed using INNOTEST xMAP immunoassays. Linear regression was used to compare regional and global measures of ¹⁸F-T807 standardized uptake value ratios (SUVR) to CSF protein levels using data from 31 cognitively unimpaired elderly participants in the Harvard Aging Brain study.

Results: After controlling for sex and age, total cortical ¹⁸F-T807 binding was significantly correlated with p-tau (partial r = 0.48; p < 0.01) and at trend level with t-tau (partial r = 0.30; p = 0.12). Regional ¹⁸F-T807 measures were more strongly correlated with CSF protein levels than the global measure, with both t-tau and p-tau significantly correlated with ¹⁸F-T807 SUVR in entorhinal, parahippocampal, and inferior temporal cortical regions (partial r = 0.53–0.73). Peak correlations between CSF and PET measures of tau were similar to those between CSF and PET measures of amyloid burden. Finally, we observed significantly higher temporal T807 SUVR in individuals with high amyloid burden.

Conclusions: These data support the link between ¹⁸F-T807 PET and CSF measures of tau pathology. In these cognitively normal individuals with ¹⁸F-T807 binding largely restricted to the temporal lobe, ¹⁸F-T807 SUVR in temporal regions appeared more reflective of CSF t-tau and p-tau than a total cortical measure.

Neurology 2016