International quality control survey of neurochemical dementia diagnostics

Currently, neurochemical dementia diagnostics (NDD) are increasingly entering routine clinical neurochemistry, offering improved early and differential diagnosis of dementias. However, there is an obvious lack of standardization in pre-analytical sample handling and systematic quality surveys. Therefore, in this study, 14 laboratories in Germany, Austria, and Switzerland were given aliquots of a human cerebrospinal fluid (CSF) sample, and were asked to measure Alzheimer's disease (AD) biomarkers (amyloid β (Aβ) peptides, total Tau protein, and phosphorylated Tau protein (P-tau 181P)) according to their routine protocols. Results: The inter-laboratory coefficients of variation of the results obtained by the laboratories participating in this study were in the range of 20–30%. Although the results of this quality control survey are promising, the quality of measurements has to be further optimized.