TY - INPR KW - Diagnostic markers KW - Predictive markers ID - discovery10107467 A1 - O'Connor, A A1 - Karikari, TK A1 - Poole, T A1 - Ashton, NJ A1 - Rodriguez, JL A1 - Khatun, A A1 - Swift, I A1 - Heslegrave, AJ A1 - Abel, E A1 - Chung, E A1 - Weston, PSJ A1 - Pavisic, IM A1 - Ryan, NS A1 - Barker, S A1 - Rossor, MN A1 - Polke, JM A1 - Frost, C A1 - Mead, S A1 - Blennow, K A1 - Zetterberg, H A1 - Fox, NC UR - https://doi.org/10.1038/s41380-020-0838-x N2 - Blood biomarkers have great potential to advance clinical care and accelerate trials in Alzheimer?s disease (AD). Plasma phospho-tau181 (p-tau181) is a promising blood biomarker however, it is unknown if levels increase in presymptomatic AD. Therefore, we investigated the timing of p-tau181 changes using 153 blood samples from 70 individuals in a longitudinal study of familial AD (FAD). Plasma p-tau181 was measured, using an in-house single molecule array assay. We compared p-tau181 between symptomatic carriers, presymptomatic carriers, and non-carriers, adjusting for age and sex. We examined the relationship between p-tau181 and neurofilament light and estimated years to/from symptom onset (EYO), as well as years to/from actual onset in a symptomatic subgroup. In addition, we studied associations between p-tau181 and clinical severity, as well testing for differences between genetic subgroups. Twenty-four were presymptomatic carriers (mean baseline EYO ?9.6 years) while 27 were non-carriers. Compared with non-carriers, plasma p-tau181 concentration was higher in both symptomatic (p?<?0.001) and presymptomatic mutation carriers (p?<?0.001). Plasma p-tau181 showed considerable intra-individual variability but individual values discriminated symptomatic (AUC 0.93 [95% CI 0.85?0.98]) and presymptomatic (EYO????7 years) (AUC 0.86 [95% CI 0.72?0.94]) carriers from non-carriers of the same age and sex. From a fitted model there was evidence (p?=?0.050) that p-tau181 concentrations were higher in mutation carriers than non-carriers from 16 years prior to estimated symptom onset. Our finding that plasma p-tau181 concentration is increased in symptomatic and presymptomatic FAD suggests potential utility as an easily accessible biomarker of AD pathology. AV - public JF - Molecular Psychiatry EP - 10 TI - Plasma phospho-tau181 in presymptomatic and symptomatic familial Alzheimer's disease: a longitudinal cohort study Y1 - 2020/07/14/ PB - NATURE PUBLISHING GROUP N1 - This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions. ER -