Clinical Evaluation of Blood-Based Assays for Rapid Detection of Aβ Pathology in Alzheimer's Disease

The CLEAR-AD study is an ongoing population-based cross-sectional study, currently recruiting 400 participants in ten centers in China. The study includes cognitively normal controls, individuals with mild cognitive impairment (MCI) - categorized as amyloid-positive and amyloid-negative - as well as patients with dementia, also divided into amyloid-positive and amyloid-negative groups. All participants undergo amyloid PET scans using tracers such as AV1, AV45, and PIB. Blood samples are collected within three months prior to the PET scan or from existing samples collected after January 1, 2024, that meet quality standards. After collection, these samples are analyzed at a central laboratory under blinded conditions using multiple detection methods to measure plasma levels of Aβ40, Aβ42, t-tau, and p-tau181/217. The detection technologies included single-molecule immunoassay, digital immunoassay chips, magnetic particle chemiluminescence, and flow cytometry fluorescence. The objective i