Blood-based Biomarkers and the Current Landscape of Alzheimer's Disease Diagnosis: Ethical Considerations and Practical Guidance.

Recent advances in biomarker testing for Alzheimer's disease (AD), most notably the introduction of blood-based biomarkers (BBMs), have prompted a revision in diagnostic criteria for AD. In comparison to other established neurodiagnostic testing (i.e. amyloid positron emission tomography [PET] and cerebral spinal fluid [CSF] assays), AD BBMs offer a scalable, low-cost, and accessible method to aid in the diagnosis of AD which, in turn, may offer more expedient intervention. Despite this headway in AD diagnosis, several concerns about the clinical implementation of BBMs remain--and specifically, who should be receiving them. Palmqvist et al. (2025) recently published clinical practice guidelines to clarify the use of BBMs in specialty care settings; however, there remains variability in the administration and interpretation of test results to patients. As BBMs expand, it is critical that clinicans do not overlook the consideration of alternative causes of cognitive decline, which can lead to misdiagnosis of AD. This article expands on current clinical guidelines for biomarker testing, discussing ethical and practical considerations of AD BBMs, and offering a shared decision-making (SDM) framework to encourage patient-centered care when considering appropriateness of BBMs in specialty care settings. The framework includes 1) patient education, 2) clarifying patient values, and 3) offering clinical guidance. Future directions of AD BBMs and health disparities are also discussed.