Plasma p-tau231 increases at one-year intervals in cognitively unimpaired subjects

Abstract BACKGROUND: Plasma biomarkers indicative of Alzheimer's disease pathology constitute a non-invasive tool for diagnosing and classifying the disease. They are altered even in preclinical stages. Nonetheless, it is necessary to better understand their properties so they can be helpful in a clinical context. METHODS: We have evaluated plasma phosphorylated (p)-tau231 in a group of 146 cognitively unimpaired subjects in sequential visits and correlated their levels with different phenotypic traits. ATN status was defined based on CSF biomarkers. RESULTS: P-tau231 levels increase sequentially at intervals close to one year. This increase occurs even in A-T-N- subjects. Basal levels of p-tau231 correlate negatively with memory tests only in subjects with a sufficient amyloid load. CONCLUSIONS: P-tau231 is a sensitive marker for detecting early signs of neuronal network impairment by amyloid. Longer-term studies are needed to characterize better p-tau231 evolution and its relationship with the different phases of the disease.