Serum Neuron-Specific Enolase and High-Sensitivity C-Reactive Protein Expression Levels and Their Clinical Significance in Patients With Alzheimer's Disease.

Aims/Background Alzheimer's disease (AD) is a degenerative disease of the central nervous system. Identifying effective and highly specific serum biomarkers is crucial for the early diagnosis and therapeutic monitoring of AD. This study aimed to explore the serum levels of neuron-specific enolase (NSE) and high-sensitivity C-reactive protein (hs-CRP) and their clinical significance in AD patients. Methods This retrospective study recruited 112 AD patients hospitalized between June 2021 and June 2023 as an AD group. For comparison, 80 healthy individuals who underwent physical examination during the same period were selected as the control group. The levels of NSE and hs-CRP were assessed using enzyme-linked immunosorbent assay (ELISA). The levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were also determined using ELISA. Furthermore, the severity of cognitive impairment was evaluated using the Mini-mental State Examination (MMSE) score, the Global Deterioration Scale (GDS), and the Clinical Dementia Rating Scale (CDR). Pearson correlation analysis was used to analyze the correlation between serum NSE and hs-CRP levels and disease-related indicators in the AD group, and the receiver operating characteristic (ROC) was used to analyze their diagnostic efficacy. Results The AD group exhibited significantly higher GDS and CDR scores, as well as serum NSE and hs-CRP levels, and significantly lower MMSE scores compared to the control group (p < 0.001). GDS and CDR scores, and serum NSE and hs-CRP levels were significantly higher in the moderate-to-severe group than in the mild group, and significantly lower MMSE scores (p < 0.001). Pearson correlation analysis revealed that serum NSE and hs-CRP levels were negatively correlated with MMSE scores in AD patients (p < 0.05) and were positively correlated with GDS and CDR scores (p < 0.05). ROC curve analysis showed that the serum NSE (area under the curve [AUC]: 0.856, 95% CI 0.787-0.925, p < 0.001) and hs-CRP (AUC: 0.728, 95% CI 0.631-0.825, p < 0.001) levels individually had significant diagnostic efficacy for AD; however, the combined assessment of their levels (AUC: 0.879, 95% CI 0.815-0.943, p < 0.001) demonstrated higher diagnostic efficacy than hs-CRP alone (p < 0.001). Conclusion Serum NSE and hs-CRP levels are closely associated with the cognitive function in AD patients, and their combined evaluation exhibits a higher diagnostic value.