[Clinically validated molecular biomarkers of neurodegenerative dementia]

As cerebrospinal fluid-based neurochemical dementia diagnostics (CSF-NDD) has now been validated at the S3 evidence level, the German Association for Psychiatry, Psychotherapy and Psychosomatics (DGPPN) and the German Society for Neurology (DGN) recommend CSF-NDD in the recent joint dementia guidelines for improved early and differential diagnostics of multigenic (sporadic) Alzheimer's dementia (AD). The CSF-NDD also provides a predictive diagnosis of incipient AD for high-risk patients when they are still in the prodromal stage of mild cognitive impairment (MCI) but as no (secondary) preventive therapy of AD is currently available, the use of CSF-NDD for the predictive molecular diagnosis of AD is not recommended in the neuropsychiatry guidelines (http://www.DGPPN.de). However, molecular diagnostics of preclinical AD by CSF-NDD and/or [18F]-amyloid positron emission tomography (PET) has meanwhile gained high clinical relevance for therapeutic clinical research, as this novel clinical model allows systematic screening for promising (secondary) preventive therapy options. Moreover, it has now become apparent that blood-based neurochemical diagnostics of preclinical and early AD will be possible by means of various formats of multiplex assays. However, so far promising blood assays have not been consistently validated by independent research groups and in contrast to CSF-NDD a blood-based diagnosis of AD is not yet available.