Abstract

Background: A major drawback in Alzheimer's disease (AD) is the lack of validated biomarkers for routine clinical diagnostic. We have reported earlier a novel blood biomarker, named Alz-tau®, based on variants of platelet tau. This marker evaluates the ratio of high molecular weight tau (HMWtau) and the low molecular weight (LMWtau) tau. Objective: To analyze a potential novel source of antigen for Alz-tau®, plasma tau, detected by immunoreactivity with the novel monoclonal antibody, tau51. Methods: We evaluated tau variants in plasma precipitated with ammonium sulfate from 36 AD patients and 15 control subjects by western blot with this novel monoclonal antibody. Results: The HMW/LMWtau ratio was statistically different between AD patients and controls. Conclusions: Plasma tau variants are suitable to be considered as a novel antigen source for the Alz-tau® biomarker for AD.