Woo MS, Tissot C, Lantero-Rodriguez J, Snellman A, Therriault J, Rahmouni N, Macedo AC, Servaes S, Wang YT, Arias JF, Hosseini SA, Chamoun M, Lussier FZ, Benedet AL, Ashton NJ, Karikari TK, Triana-Baltzer G, Kolb HC, Stevenson J, Mayer C, Kobayashi E, Massarweh G, Friese MA, Pascoal TA, Gauthier S, Zetterberg H, Blennow K, Rosa-Neto P.
„Introduction: We set out to identify tau PET-positive (A+T+) individuals among amyloid-beta (Aβ) positive participants using plasma biomarkers. Methods: In this cross-sectional study we assessed 234 participants across the AD continuum who were evaluated by amyloid PET with [18 F]AZD4694 and tau-PET with [18 F]MK6240 and measured plasma levels of total tau, pTau-181, pTau-217, pTau-231, and N-terminal tau (NTA-tau). We evaluated the performances of plasma biomarkers to predict tau positivity in Aβ+ individuals. Results: Highest associations with tau positivity in Aβ+ individuals were found for plasma pTau-217 (AUC [CI95% ] = 0.89 [0.82, 0.96]) and NTA-tau (AUC [CI95% ] = 0.88 [0.91, 0.95]). Combining pTau-217 and NTA-tau resulted in the strongest agreement (Cohen’s Kappa = 0.74, CI95% = 0.57/0.90, sensitivity = 92%, specificity = 81%) with PET for classifying tau positivity. Discussion: The potential for identifying tau accumulation in later Braak stages will be useful for patient stratification and prognostication in treatment trials and in clinical practice. Highlights: We found that in a cohort without pre-selection pTau-181, pTau-217, and NTA-tau showed the highest association with tau PET positivity. We found that in Aβ+ individuals pTau-217 and NTA-tau showed the highest association with tau PET positivity. Combining pTau-217 and NTA-tau resulted in the strongest agreement with the tau PET-based classification.“Alzheimers Dement. 2024 Feb;20(2):1166-1174.
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