Background: Advances in proteomic technologies enable sensitive plasma-based profiling for early detection and mechanistic understanding of Alzheimer’s disease (AD). We evaluated the NULISAseq central nervous system (CNS) panel in individuals with cognitive impairment to identify amyloid-associated plasma biomarkers.

Methods: Plasma biomarkers were quantified in 153 participants (79 Aβ+ and 74 Aβ-). Plasma Aβ42, p-tau181, p-tau217, and p-tau/Aβ42 ratios were additionally measured using Lumipulse and Simoa. Based on differential markers, a multi-protein panel was constructed, and associations with amyloid burden, cognition, and demographic factors were examined. Bioinformatic analyses were further performed.

Results: Core AD biomarkers showed strong concordance across NULISAseq, Lumipulse, and Simoa platforms. Thirty-seven proteins differed between Aβ+ and Aβ- groups after false discovery rate correction. ENO2 and ARSA demonstrated high discriminatory performance for amyloid pathology, including early stages, and correlated with cerebral amyloid burden. A seven-protein panel derived from LASSO regression achieved excellent classification of Aβ status (AUC = 0.96, 95% CI: 0.93–0.98) with internal cross-validation. Enrichment analyses indicated that these markers are involved in neuroinflammatory pathways, while protein-protein interaction analysis highlighted tau-centered networks and suggested additional mechanisms beyond tau pathology.

Conclusions: We identified ENO2 and ARSA as novel plasma biomarkers of AD with high diagnostic value. These findings provide biological insights into disease mechanisms, suggesting processes beyond classical AD pathology.