Elevated MicroRNA-146a in Alzheimer's Disease and Its Diagnostic Potential

Alzheimer's disease (AD) is a progressive neurological condition marked by memory impairment and cognitive deterioration. Early diagnosis remains difficult due to the absence of reliable peripheral biomarkers. Circulating microRNAs (miRNAs) have recently gained attention as non-invasive indicators measurable in blood. Among these, microRNA-146a is of particular interest because of its role in inflammatory signaling and its altered expression in AD. This article highlights the diagnostic potential and biological function of microRNA-146a as a peripheral biomarker for Alzheimer's disease. The current study aimed to examine the expression and clinical relevance of microRNA-146a and to assess its possible influence on disease progression in Alzheimer's disease patients. Blood samples were collected after obtaining signed informed consent (No. 3912/2022 MRB) from 50 AD patients and from 50 healthy controls (HC); the miRNA content was screened by RT-PC. The expression of miRNA-146a is significantly greater in the Alzheimer's disease group (4.369 ± 3.168 -fold change) than in the control group (1.056 ± 0.702) (p < 0.001). In order to evaluate miR146a expression efficiency, a receiver operating characteristic (ROC) curve showed miR146a exhibited strong discriminative capability, with an AUC of 0.906 (95% CI 0.83-0.98). At a threshold of 2.21, the sensitivity was 90% and the specificity was 92%, demonstrating exceptional diagnostic efficacy. Logistic regression showed a strong inverse association trend (B = -6.803, OR = 0.001), with borderline statistical significance (p = 0.09). Cross-tabulation with Chi-square test confirmed a highly significant association between miR-146a expression and disease status (p < 0.001). A decision tree using Exhaustive CHAID further supported the finding, achieving 90% classification accuracy with a split point at 2.195. Collectively, these results demonstrate the robustness of miR-146a as a potential biomarker for distinguishing Alzheimer's patients from healthy individuals. An increase was found in the content of expression of microRNA-146a in AD patients compared with HC. Level of microRNA-146a, and correlated with disease; might be used as a biomarker reflecting AD.