AUTHORS: Mendes A. J., Ribaldi F., Lathuiliere A., Ashton N. J., Janelidze S., Zetterberg H., Scheffler M., Assal F., Garibotto V., Blennow K., Hansson O., Frisoni G. B.

Journal of Neurology, 271(4): 2053-2066, 09 January 2024


ABSTRACT

Background and objective

Phosphorylated tau (p-tau) 217 has recently received attention because it seems more reliable than other p-tau variants for identifying Alzheimer’s disease (AD) pathology. Thus, we aimed to compare the diagnostic accuracy of plasma and CSF p-tau217 with p-tau181 and p-tau231 in a memory clinic cohort.

Methods

The study included 114 participants (CU = 33; MCI = 67; Dementia = 14). The p-tau variants were correlated versus continuous measures of amyloid (A) and tau (T)-PET. The p-tau phospho-epitopes were assessed through: (i) effect sizes (δ) between diagnostic and A ± and T ± groups; (ii) receiver operating characteristic (ROC) analyses in A-PET and T-PET.

Results

The correlations between both plasma and CSF p-tau217 with A-PET and T-PET (r range 0.64–0.83) were stronger than those of p-tau181 (r range 0.44–0.79) and p-tau231 (r range 0.46–0.76). Plasma p-tau217 showed significantly higher diagnostic accuracy than p-tau181 and p-tau231 in (i) differences between diagnostic and biomarker groups (δrangep-tau217 = 0.55–0.96; p-tau181 = 0.51–0.67; p-tau231 = 0.53–0.71); (ii) ROC curves to identify A-PET and T-PET positivity (AUCaveragep-tau217 = 0.96; p-tau181 = 0.76; p-tau231 = 0.79). On the other hand, CSF p-tau217 (AUCaverage = 0.95) did not reveal significant differences in A-PET and T-PET AUC than p-tau181 (AUCaverage = 0.88) and p-tau231 (AUCaverage = 0.89).

Discussion

Plasma p-tau217 demonstrated better performance in the identification of AD pathology and clinical phenotypes in comparison with other variants of p-tau in a memory clinic cohort. Furthermore, p-tau217 had comparable performance in plasma and CSF. Our findings suggest the potential of plasma p-tau217 in the diagnosis and screening for AD, which could allow for a decreased use of invasive biomarkers in the future.


BibTex

https://doi.org/10.1007/s00415-023-12148-5


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