Round robin test on quantification of amyloid-β 1-42 in cerebrospinal fluid by mass spectrometry

Background: Cerebrospinal fluid amyloid-β 1-42 (Aβ42) is an important biomarker for Alzheimer’s disease, both in diagnostics and to monitor disease-modifying therapies. However, there is a great need for harmonization of methods used for quantification. To overcome problems associated with immunoassays, mass spectrometry (MS) has emerged as a critical alternative. Methods: We compared results for CSF Aβ42 quantification in a Round Robin study, performed in four laboratories using similar sample preparation methods and triple quadrupole MS instrumentation. Results: The MS results showed excellent correlation between laboratories (R2 > 0.98), high analytical precision, and good correlation with ELISA (R2 > 0.85). The use of a common reference sample further decreased inter-laboratory variation. Conclusions: Our results indicate that MS is suitable for absolute quantification of Aβ42 in CSF and highlights the importance of developing a certified reference material.JRC.D.2-Standards for Innovation and sustainable Developmen