Immunoassay and Mass Spectrometry Methods for Tau Protein Quantification in the Cerebrospinal Fluid

Abstract

Quantification of tau proteins in the cerebrospinal fluid is a major biomarker for the positive diagnosis of Alzheimer’s disease, as well as for other neurodegenerative diseases and brain damage monitoring. Tau is present in this fluid in multiple proteoforms, different by their lengths and phosphorylation sites. Immunodetection approaches for “total” tau and its phosphorylation form pTau(181) are now being used in routine with IVD qualified kits represented by classical ELISA and fully automatized systems. There is however a need for a reference method represented by mass spectrometry which could help to homogenize results across platforms and help to decipher the diversity of the tau isoforms in CSF.