Blood-based emerging biomarkers in early detection and diagnosis of Alzheimer's disease.

In the medical field, such as oncology and cardiovascular diseases, biomarker discovery and development for clinical research, diagnostics, and therapy monitoring in clinical trials have advanced quickly. This has facilitated the development of biomarker-guided, precision-medicine-based targeted therapies and helped in quick and early detection. Cerebrospinal fluid and PET indicators of tau and amyloid-β proteins are among the biomarker discovery and validation advances in Alzheimer's disease (AD). They have shown remarkable accuracy in identifying the presence of pathophysiological and neuropathological alterations linked to AD. However, these assays' high cost, lack of accessibility, and/or invasiveness restrict their applicability as practical first-line methods for identifying pathophysiological patterns. However, the concentrations of brain-derived chemicals in blood are significantly lower than those in CSF, which presents an analytical problem. Blood, as a biofluid to evaluate biomarkers for diseases of the central nervous system, has further problems. However, there has been a significant advancement in recent years. The current status of research on blood biomarkers for AD and associated neurodegenerative dementias is updated in this chapter.