Fluid and PET biomarkers for amyloid pathology in Alzheimer's disease.

Alzheimer's disease (AD) is characterized by amyloid plaques and tau pathology (neurofibrillary tangles and neuropil threads). Amyloid plaques are primarily composed of aggregated and oligomeric ß-amyloid (Aß) peptides ending at position 42 (Aß42). The development of fluid and PET biomarkers for Alzheimer's disease (AD), has allowed for detection of Aß pathology in vivo and marks a major advancement in understanding the role of Aß in Alzheimer's disease (AD). In the recent National Institute on Aging and Alzheimer's Association (NIA-AA) Research Framework, AD is defined by the underlying pathology as measured in patients during life by biomarkers (Jack et al., 2018), while clinical symptoms are used for staging of the disease. Therefore, sensitive, specific and robust biomarkers to identify brain amyloidosis are central in AD research. Here, we discuss fluid and PET biomarkers for Aß and their application.