Current technological advancements in clinical and research settings have permitted a more intensive and comprehensive understanding of Alzheimer’s disease (AD). This development in knowledge regarding AD pathogenesis has been implemented to produce disease-modifying drugs. The potential for accessible and effective therapeutic methods has generated a need for detecting this neurodegenerative disorder during early stages of progression because such remedial effects are more profound when implemented during the initial, prolonged prodromal stages of pathogenesis. The aggregation of amyloid-β (Aβ) and tau isoforms are characteristic of AD; thus, they are considered core candidate biomarkers. However, research attempting to establish the reliability of Aβ and tau as biomarkers has culminated in an amalgamation of contradictory results and theories regarding the biomarker concentrations necessary for an accurate diagnosis. In this review, we consider the capabilities and limitations of fluid biomarkers collected from cerebrospinal fluid, blood, and oral, ocular, and olfactory secretions as diagnostic tools for AD, along with the impact of the integration of these biomarkers in clinical settings. Furthermore, the evolution of diagnostic criteria and novel research findings are discussed. This review is a summary and reflection of the ongoing concerted efforts to establish fluid biomarkers as a diagnostic tool and implement them in diagnostic procedures.
Bibliographical noteFunding Information:
This work was supported by the Korea Health Industry Development Institute (KHIDI, HI14C3319), National Research Foundation (Basic Science Research Program NRF-2018R1A6A1A03023718 and Original Technology Research Program for Brain Science NRF-2018M3C7A1021858), and Yonsei University (2018-22-0022 and Yonsei Frontier Lab). All images were created by the authors for this manuscript.
All Science Journal Classification (ASJC) codes
- Molecular Medicine
- Molecular Biology
- Clinical Biochemistry