Blood phosphorylated Tau181 reliably differentiates amyloid‐positive from amyloid‐negative subjects in the Alzheimer's disease continuum: A systematic review and meta‐analysis

Abstract

Abstract INTRODUCTION Blood‐based biomarkers seem promising for the diagnosis of Alzheimer's disease (AD). METHODS We performed a systematic review and meta‐analysis on the potential of blood phosphorylated Tau181 (p‐tau181) to differentiate amyloid‐positive (A+) and amyloid‐negative (A−) subjects. Two meta‐analyses were conducted, showing the mean p‐tau values in blood and cerebrospinal fluid (CSF) in the A+ and A− group, and the second comparing the mean p‐tau concentrations in blood and CSF among A+ versus A‐ participants, by laboratory assessment method. RESULTS Eighteen studies (2764 A+ and 5646 A− subjects) were included. The single‐group meta‐analysis showed mean higher blood p‐tau181 values in the A+ than in the A− group. In the head‐to‐head meta‐analysis, blood p‐tau reliably differentiated A+ patients from A− participants. DISCUSSION Regardless of the laboratory technique, blood p‐tau181 reliably differentiates A+ and A− subjects. Therefore, it might have important applications for early diagnosis and inclusion in clinical trials for AD patients. Highlights The role of blood‐based biomarkers in discriminating AD patients is still uncertain. Blood p‐tau181 distinguishes among amyloid‐positive and amyloid‐negative subjects. Blood p‐tau181 might allow early diagnosis and inclusion in clinical trials.

Keywords

• Alzheimer's disease (AD)
• biomarkers
• blood
• CSF
• meta‐analysis
• phosphorylated Tau181 (p‐tau181)