Critical Assessment of the Status of Biomarkers for Alzheimer’s disease

Objective: We undertook a critical analysis of the status of the progress in the development of biomarkers for the detection of Alzheimer’s disease (AD). Methods: Biomarker studies involving imaging, metabolomics, lipidomics, proteomics, transcriptomics and microRNAs were assessed from publications between 2004 and 2014. Results: Extensive efforts have been applied to the development of minimally invasive and inexpensive assays for the early detection of AD. However, the failure to replicate findings between laboratories has presented a significant challenge in validating assays for clinical use. Larger scale studies and collaborations are required to standardize sample collection and storage, analytical methodology, and to control for heterogeneity in the AD patient population. Conclusions: Since cognitive testing cannot detect the presymptomatic stages of AD, validated biomarkers are essential for advancing both AD research and clinical practice. Despite intensive research over the last 10 years, there currently are no validated biomarkers for the early detection of AD.