Upregulation of Circulating miR-4466 as a Novel Diagnostic Biomarker for Alzheimer’s Disease: A Case-Control Study

Introduction: Alzheimer's disease (AD) is a progressive neurodegenerative disorder lacking conclusive early-stage diagnostic tools. There is a critical and unmet need for accessible, reliable biomarkers. MicroRNAs (miRNAs) have emerged as promising candidates due to their stability in biofluids and their role in regulating gene expression pathways relevant to AD pathogenesis. This study aimed to investigate miR-4466 expression and evaluate its potential as a diagnostic biomarker for AD.

Methods: We conducted a case-control study involving 80 patients diagnosed with AD and 80 age-matched healthy controls. Total RNA was extracted using TRIzol LS from plasma, and miR-4466 expression was quantified by qRT-PCR. The relative expression levels of miR-4466 were quantified (normalized to U6) in all participants. Statistical significance of the difference in expression between the two groups was assessed using the non-parametric Mann-Whitney U test. The diagnostic accuracy of miR-4466 was subsequently determined using the Receiver Operating Characteristic (ROC) curve analysis.

Results: Our findings revealed a statistically significant upregulation of miR-4466 expression in the AD patients compared to the healthy control group (AD median = 0.08719 vs. Control median = 0.02886; P < 0.0001). The ROC analysis demonstrated an acceptable diagnostic utility for miR-4466 in distinguishing AD patients from controls. The Area Under the Curve (AUC) was 0.7838 (95% CI: 0.7142–0.8533; P < 0.0001), achieving a sensitivity of 78.75% and a specificity of 66.25% at the optimal threshold.

Conclusion: This study demonstrates the significant clinical diagnostic potential of miR-4466 in AD patients. These results highlight miR-4466 as a novel, non-invasive biomarker for accessible early-stage screening. Further validation in larger, diverse cohorts is required to confirm its clinical utility.