Bayoumy, SherifVerberk, Inge M.W.den Dulk, BenHussainali, ZulaigaZwan, Marissavan der Flier, Wiesje M.Ashton, Nicholas J.Zetterberg, HenrikBlennow, KajVanbrabant, JeroenStoops, ErikVanmechelen, EugeenDage, Jeffrey L.Teunissen, Charlotte E.2023-04-112023-04-112021-12-04Bayoumy S, Verberk IMW, den Dulk B, et al. Clinical and analytical comparison of six Simoa assays for plasma P-tau isoforms P-tau181, P-tau217, and P-tau231. Alzheimers Res Ther. 2021;13(1):198. Published 2021 Dec 4. doi:10.1186/s13195-021-00939-9https://hdl.handle.net/1805/32339Introduction: Studies using different assays and technologies showed highly promising diagnostic value of plasma phosphorylated (P-)tau levels for Alzheimer's disease (AD). We aimed to compare six P-tau Simoa assays, including three P-tau181 (Eli Lilly, ADx, Quanterix), one P-tau217 (Eli Lilly), and two P-tau231 (ADx, Gothenburg). Methods: We studied the analytical (sensitivity, precision, parallelism, dilution linearity, and recovery) and clinical (40 AD dementia patients, age 66±8years, 50%F; 40 age- and sex-matched controls) performance of the assays. Results: All assays showed robust analytical performance, and particularly P-tau217 Eli Lilly; P-tau231 Gothenburg and all P-tau181 assays showed robust clinical performance to differentiate AD from controls, with AUCs 0.936-0.995 (P-tau231 ADx: AUC = 0.719). Results obtained with all P-tau181 assays, P-tau217 Eli Lilly assay, and P-tau231 Gothenburg assay strongly correlated (Spearman's rho > 0.86), while correlations with P-tau231 ADx results were moderate (rho < 0.65). Discussion: P-tau isoforms can be measured robustly by several novel high-sensitive Simoa assays.en-USAttribution 4.0 InternationalAlzheimer’s diseaseAnalytical validationBlood biomarkersClinical validationP-tau181P-tau217P-tau231Phosphorylated tau proteinsSimoaUltra-sensitive immunoassaysArticle