Revolutionizing Alzheimer's Diagnosis and Management: The Dawn of Biomarker-Based Precision Medicine.

Alzheimer's disease (AD), a leading cause of dementia, presents a formidable global health challenge intensified by the aging population. This review encapsulates the evolving landscape of AD diagnosis and treatment with a special focus on the innovative role of fluid biomarkers. Pathologically, AD is marked by amyloid beta (Aβ) plaques and neurofibrillary tangles of hyperphosphorylated tau, which lead to synaptic dysfunction, neuronal loss, and cognitive decline. These pathological changes, commencing decades before symptom onset, underscore the need for early detection and intervention. Diagnosis traditionally relies on clinical assessment, neuropsychological testing, and neuroimaging techniques. However, fluid biomarkers in cerebrospinal fluid and blood, such as various forms of Aβ, total tau, phosphorylated tau, and neurofilament light chain, are emerging as less invasive, cost-effective diagnostic tools. These biomarkers are pivotal for early diagnosis, differential diagnosis, disease progression monitoring, and treatment response evaluation. The treatment landscape is shifting toward personalized medicine, highlighted by advancements in Aβ immunotherapies, such as lecanemab and donanemab. Demonstrating efficacy in phase III clinical trials, these therapies hold promise as tailored treatment strategies based on individual biomarker profiles. The integration of fluid biomarkers into clinical practice represents a significant advance in AD management, providing the potential for early and precise diagnosis, coupled with personalized therapeutic approaches. This heralds a new era in combating this debilitating disease.