Association of miR-146a/b and miR-181a with Chronic Obstructive Pulmonary Disease

miRNAs play critical roles in regulating inflammatory responses in chronic obstructive pulmonary disease (COPD). This study investigated the expression patterns of miR-146a/b and miR-181a, along with associated inflammatory mediators, in COPD patients. This cross-sectional study included 40 patients with acute exacerbation of COPD (AECOPD), 40 patients with stable COPD, and 40 healthy controls. Expression levels of miR-146a, miR-146b, and miR-181a in peripheral blood mononuclear cells (PBMCs) were quantified using quantitative real-time PCR. Serum concentrations of high-mobility group box 1 (HMGB1), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-10 (IL-10) were measured by ELISA. Cytokine mRNA expression was assessed in PMA-stimulated PBMCs. Multivariable logistic regression was performed to adjust for potential confounders including age and smoking pack-years. Expression of miR-146a, miR-146b, and miR-181a was significantly decreased in both COPD and AECOPD groups compared to controls (all p < 0.001), with further reduction in AECOPD patients. Multivariable analysis demonstrated that decreased miR-146a (OR = 2.45, 95% CI: 1.58-3.81, p < 0.001) and miR-181a (OR = 2.18, 95% CI: 1.42-3.35, p < 0.001) remained independent predictors of COPD after adjusting for age and smoking exposure. Serum HMGB1, IL-6, and TNF-α levels were significantly elevated in COPD patients, while IL-10 showed decreased expression. PMA-stimulated PBMCs from COPD patients demonstrated enhanced pro-inflammatory cytokine production capacity. In exploratory ROC analysis, miR-146a showed moderate discriminatory capacity (AUC = 0.78, 95% CI: 0.65-0.91). Dysregulation of miR-146a/b and miR-181a is independently associated with COPD, even after accounting for smoking exposure. These findings suggest potential roles in disease pathophysiology, though prospective validation in larger, independent cohorts is required before clinical applicability can be determined.