Blood-Based Biomarkers for Alzheimer’s Disease Diagnosis

Accurate diagnosis of Alzheimer’s disease (AD) in clinical practice is still difficult. The available diagnostic tools, cerebrospinal fluid (CSF), and neuroimaging biomarkers suffer from important methodological and practical limitations. Emerging blood-based biomarkers have the potential to overcome these caveats since they are virtually cost-effective and easily accessible for widespread clinical use. Growing lines of recent evidence have clearly shown that serum/plasma β-secretase (BACE1) may be regarded as one of the most promising candidates of this group. This enzyme is a key player in the amyloidogenic pathway, and the change in its concentration and activity in the brain, CSF, and blood appears to correlate with AD-related neuropathological changes and cognitive decline. Here, we describe the spectrofluorimetric method that we have recently optimized for detecting the serum/plasma activity of BACE1. We also describe the main pros and cons of the methodology. Our main aim is to provide the reader with an easy-to-follow methodological protocol that allows to assess this highly promising biomarker for AD in a time- and cost-effective way.