ABSTRACT
In general, a biomarker denes a biological process or disease characteristic that is objectively measured (Biomarkers Denitions Working Group, 2001). Such measurements may be used for diagnostic purposes, but also to study physiological or pathophysiological mechanisms and to evaluate desired pharmacodynamic eects or side eects of pharmacological treatments. According to Biomarkers Denitions Working Group: ‘Molecular and Biochemical Markers of Alzheimer’s Disease’, the ideal biomarker for Alzheimer’s disease (AD) should detect a fundamental feature of neuropathology and be validated in neuropathologically con-rmed cases as well as have a diagnostic accuracy of at least 80% (e Ronald and Nancy Reagan Research Institute of the Alzheimer’s Association and National Institute on Aging Working Group, 1998). With respect to clinically relevant questions, such as detection, diagnosis, prediction and treatment of a given disease, biomarkers may serve certain distinct functions (Hampel et al., 2010b; Hampel and Lista, 2013), which are detailed in Table 51.1.
