Cerebrospinal fluid biomarkers for Alzheimer's disease: more to come?

The past decades have witnessed an enormous expansion of the literature on cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease (AD). It is now clear that a triplet of CSF biomarkers (total-tau, phospho-tau, and the 42 amino acid fragment of amyloid-β) reflects core neuropathological features of AD and contributes diagnostically relevant information if measured in a proper manner. Here, we discuss what is needed for these biomarkers to become generally implemented in the clinical routine. We also discuss novel CSF biomarkers, the challenge of differential diagnosis-making in diseases with shared pathologies, and if CSF biomarkers will survive in the long run, given the advancements in molecular neuroimaging and ultra-sensitive blood tests.