Blood biomarkers in Alzheimer's disease

Introduction: The early diagnosis of Alzheimer's disease (AD) via the use of biomarkers could facilitate the implementation and monitoring of early therapeutic interventions with the potential capacity to significantly modify the course of the disease.

Development: Classic cerebrospinal fluid biomarkers and approved structural and functional neuroimaging have a limited clinical application given their invasive nature and/or high cost. The identification of more accessible and less costly biomarkers, such as blood biomarkers, would facilitate application in clinical practice. We present a literature review of the main blood biochemical biomarkers with potential use for diagnosing Alzheimer's disease.

Conclusions: Blood biomarkers are cost and time effective with regard to cerebrospinal fluid biomarkers. However, the immediate applicability of blood biochemical biomarkers in clinical practice is not very likely. The main limitations come from the difficulties in measuring and standardising thresholds between different laboratories and in failures to replicate results. Among all the molecules studied, apoptosis and neurodegeneration biomarkers and the biomarker panels obtained through omics approaches, such as isolated or combined metabolomics, offer the most promising results.