Standardization of preanalytical aspects of cerebrospinal fluid biomarker testing for Alzheimer's disease diagnosis: A consensus paper from the Alzheimer's Biomarkers Standardization Initiative

Background: Numerous studies show that the cerebrospinal fluid biomarkers total tau (T-tau), tau phosphorylated at threonine 181 (P-tau(181P)), and amyloid-beta (1-42) (A beta(1-42)) have high diagnostic accuracy for Alzheimer's disease. Variability in concentrations for A beta(1-42), T-tau, and P-tau(181P) drives the need for standardization. Methods: Key issues were identified and discussed before the first meeting of the members of the Alzheimer's Biomarkers Standardization Initiative (ABSI). Subsequent ABSI consensus meetings focused on preanalytical issues. Results: Consensus was reached on preanalytical issues such as the effects of fasting, different tube types, centrifugation, time and temperature before storage, storage temperature, repeated freeze/thaw cycles, and length of storage on concentrations of A beta(1-47), T-tau, and P-tau(181P) in cerebrospinal fluid. Conclusions: The consensus reached on preanalytical issues and the recommendations put forward during the ABSI consensus meetings are presented in this paper. (C) 2012 The Alzheimer's Association. All rights reserved.