Association between a computerized, self-administered cognitive assessment and phosphorylated Tau in Alzheimer's Disease

IntroductionAlzheimers Disease (AD) is the leading cause of dementia, accounting for 80% of cases globally. With an aging population, AD poses a growing concern due to its increasing mortality rate and associated healthcare costs. Early diagnosis or prediction of AD is crucial for managing and potentially slowing its progression, particularly with the advent of disease-modifying therapies. MethodsThis study involved a total of 60 participants: 15 with mild AD, 23 with mild cognitive impairment (MCI), and 22 healthy controls, comprising both males and females aged 50-85 years. Data collection included blood samples, the Montreal Cognitive Assessment (MoCA), and the Integrated Cognitive Assessment (ICA). Serum phosphorylated tau181 (p-tau181) levels were measured using enzyme-linked immunosorbent assay (ELISA) kits. Linear regression models were applied to predict serum biomarker levels based on the ICA index, demographic data, and APOE {varepsilon}4 status. Aims and ObjectivesThe primary aim was to examine the association between ICA scores and blood-based p-tau181 levels in individual with MCI, mild AD, and elderly healthy controls. Additionally, the study compared the correlation of ICA and MoCA with APOE {varepsilon}4 status. FindingsThe study found that the ICA can significantly differentiate between diagnostic groups and that elevated serum p-tau181 levels are associated with cognitive decline, as measured by the ICA. Additionally, a significant correlation was observed between APOE {varepsilon}4 status and cognitive decline, but not between APOE {varepsilon}4 status and serum p-tau181 levels. Using a model that incorporates the ICA, demographic data, and APOE {varepsilon}4 status, we were able to modestly predict serum p-tau181 levels, indicating the potential of combining cognitive assessment with biological markers for AD prediction. DiscussionThe findings suggest that ICA is a valuable tool in detecting cognitive decline associated with AD and correlates with increased p-tau181 levels. The significant correlation between APOE {varepsilon}4 status and cognitive decline highlights its potential role in risk assessment, independent of p-tau181 levels. The study supports the use of a computerized, self-administered cognitive assessment in conjunction with blood-based biomarkers for early AD detection. Limitations include the small sample size and cross-sectional design, which restricts causal inference and longitudinal analysis. Future research should focus on larger, longitudinal studies to further validate these associations and their implications for early diagnosis and monitoring of AD progression.