Cerebrospinal fluid biomarkers in Alzheimer's disease: enhancing diagnostic precision and guiding therapeutic strategies.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with a growing global impact. Early and accurate diagnosis is crucial for effective management and therapeutic development. Cerebrospinal fluid (CSF) biomarkers have revolutionized AD diagnostics, reflecting core pathological hallmarks such as amyloid plaques and neurofibrillary tangles. Core CSF biomarkers, including amyloid-beta 42 (Aβ42), total tau (T-tau), and phosphorylated tau (p-tau), demonstrate high diagnostic accuracy, identifying AD even in early stages and predicting the conversion from mild cognitive impairment (MCI) to dementia. These biomarkers are invaluable not only for diagnosis but also for monitoring therapeutic responses in clinical trials and assessing the biochemical effects of disease-modifying treatments. This narrative review synthesizes the evolving role of CSF biomarkers in AD, focusing on their strategic application in enhancing diagnostic precision, enabling therapeutic monitoring, and facilitating clinical implementation. We explore the established utility of core CSF biomarkers, the development of novel markers, and the ongoing efforts to standardize assays and integrate these tools into routine clinical practice, ultimately aiming to improve patient outcomes and accelerate the development of effective AD interventions.