Comparison of Two Analytical Platforms in Cerebrospinal Fluid Biomarkers for the Classification of Alzheimer's Disease Spectrum with Amyloid PET Imaging

Background: Cerebrospinal fluid (CSF) amyloid-beta(1-42) (A beta(1-42)), total tau protein (t-Tau), and phosphorylated Tau (p-Tau) are ATN biomarkers for Alzheimer's disease (AD) and reflect pathogenic changes in the brain. CSF biomarkers of AD are considered for inclusion in the diagnostic criteria for research and clinical purposes to reduce the uncertainty of clinical diagnosis and to distinguish among AD stages. Objective: This study aims to compare two commercially available analytical platforms with respect to accuracy and the potential for early diagnosis of AD. Methods: A total of 211 CSF samples from healthy control (HC) and AD subjects were analyzed using two analytical platforms, INNOTEST ELISA and INNOBIA AlzBio3 xMAP kits. The accuracy of diagnosis and AUC values distinguishing study groups were compared between the two analytical platforms. Results: The absolute values for A beta(1-42), t-Tau, and p-Tau181 levels differed between the two platforms. The A beta(1-42) levels decreased, while t-Tau and p-Tau levels increased according to the AD stages. The AUC of A beta(1-42) and t-Tau, which distinguish the early stages of AD(preclinical and prodromal AD), were similar between the two platforms, whereas there were significant differences in p-Tau AUC values. CSF p-Tau using the INNOBIA was highly accurate for distinguishing both preclinical AD (AUC= 0.826, cut-off score= 38.89) and prodromal AD (AUC= 0.862, cut-off score= 41.88) from HC. Conclusion: The accuracy of CSF p-Tau levels in the preclinical and prodromal AD is higher for the INNOBIA than the INNOTEST, and the early stage AD can be accurately distinguished from HC.