Phosphorylated tau181 in plasma as a potential biomarker for Alzheimer's disease in adults with Down syndrome.

Lleó, AlbertoZetterberg, HenrikPegueroles, JordiKarikari, Thomas KCarmona-Iragui, MaríaAshton, Nicholas JMontal, VictorBarroeta, IsabelLantero-Rodríguez, JuanVidela, LauraAltuna, MirenBenejam, BessyFernandez, SusanaValldeneu, SilviaGarzón, DianaBejanin, AlexandreIulita, Maria FlorenciaCamacho, ValleMedrano-Martorell, SantiagoBelbin, OliviaClarimon, JordiLehmann, SylvainAlcolea, DanielBlesa, RafaelBlennow, KajFortea, Juan


Tau is a protein that helps to support the structure of nerves in the brain. A plasma sample, which contains proteins traveling in the bloodstream, can be used to diagnose many conditions. This study explores the potential of a specific tau protein, phosphorylated tau181, to be used as a method for diagnosis of Alzheimer’s disease in adults with Down syndrome.


Plasma tau phosphorylated at threonine 181 (p-tau181) predicts Alzheimer's disease (AD) pathology with high accuracy in the general population. In this study, we investigated plasma p-tau181 as a biomarker of AD in individuals with Down syndrome (DS). We included 366 adults with DS (240 asymptomatic, 43 prodromal AD, 83 AD dementia) and 44 euploid cognitively normal controls. We measured plasma p-tau181 with a Single molecule array (Simoa) assay. We examined the diagnostic performance of p-tau181 for the detection of AD and the relationship with other fluid and imaging biomarkers. Plasma p-tau181 concentration showed an area under the curve of 0.80 [95% CI 0.73-0.87] and 0.92 [95% CI 0.89-0.95] for the discrimination between asymptomatic individuals versus those in the prodromal and dementia groups, respectively. Plasma p-tau181 correlated with atrophy and hypometabolism in temporoparietal regions. Our findings indicate that plasma p-tau181 concentration can be useful to detect AD in DS.


Alzheimer Disease, Atrophy, Dementia, Disease Progression