Future use and implementation of AD blood biomarkers from a clinical and epidemiological perspective

Abstract Background Blood‐based biomarkers for the diagnosis and prognosis of Alzheimer’s disease are now becoming a reality. Indeed, the first plasma amyloid‐beta blood test and algorithm is available for clinical use in some locations. With the very promising plasma phosphorylated tau 181 and 217 results in the past two years, it is likely additional tests will be approved in the near future. However, many questions remain as to how blood‐based biomarkers should best be used in the clinic, including how they should be utilized in the general population and among primary care physicians. Method We will discuss some of the key considerations and steps that must be taken before implementation in the clinic, especially in primary practice. Examples will be incorporated from the existing literature and data collected in the Mayo Clinic Study of Aging. Result One consideration includes the peripheral factors that might affect the levels of the biomarkers in blood including demographics (age and sex), and comorbidities. For example, a high body mass index is associated with a larger blood volume and renal disease can affect the clearance rate of the biomarker. Another consideration is the utility of a blood‐based biomarker among those with subjective memory complaints and the corresponding ethical implications and guidance for use that is needed. A third consideration is the context of use of blood‐based biomarkers in healthcare settings would could include general screening purposes, targeted screening in people at high risk and actively seeking counseling in primary care, and/or diagnosis in specialized/tertiary care. Conclusion Blood‐based biomarkers for the diagnosis and/or prognosis of Alzheimer’s disease and related disorders are much more feasible and less costly and invasive than a lumbar puncture for the collection of cerebrospinal fluid or amyloid and tau PET imaging. However, it is critical to address several concerns prior to implementing blood‐based biomarkers into the clinic, both in specialty and primary care settings, for the interpretation of the results and upmost consideration of the patient. Specific research actions will be needed to better understand the role of peripheral factors and the use of blood biomarkers in clinical care.