Development of fully automated plasma immunoassay using by HISCLTM series for classification of neurological disorders

ATN classification system (A: β‐amyloid (Aβ) deposition, T: pathogenic tau accumulation, N: neurodegeneration) has been widely accepted as a research framework for not only characterization of Alzheimer's disease (AD), but also for discrimination of AD from other neurological disorders (OND) such as Parkinson disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). Currently, the different pathological processes are represented by the biomarker normality/abnormality which is diagnosed by neuroimaging and/or measuring the biomarker levels in cerebrospinal fluid. A simple diagnostic method needs to be established to evaluate pathological processes in routine clinical practice. Blood‐based biomarkers would be appropriate for clinical applications because of their simplicity and accessibility. We have developed plasma Aβ1‐40, Aβ1‐42, threonine‐181 phosphorylated tau (p‐tau181), and tau immunoassays and reported that the plasma biomarker levels were significantly different between AD, mild cognitive impairment (MCI), and cognitively normal (CN) groups, suggesting the possibility of characterizing AD. Here, we present the results of the ATN biomarker profile of OND samples using our fully automated assay.