Circulating miR-146a/b correlates with inflammatory cytokines in COPD and could predict the risk of acute exacerbation COPD.

The aim of this study was to investigate the predicting value of miR-146a/b for acute exacerbation chronic obstructive pulmonary disease (AECOPD) and COPD, and to explore their associations with inflammatory cytokines in AECOPD and stable COPD patients.One hundred six AECOPD, 122 stable COPD patients, and 110 health volunteers with age and sex matched to total COPD patients (AECOPD and stable COPD) were enrolled. Blood samples were collected from all participants. Relative expression of miR-146a/b was determined by real-time polymerase chain reaction. Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), leukotriene B4 (LTB-4) expression in serum from AECOPD and stable COPD patients were assessed using commercial ELISA kit.Serum levels of miR-146a and miR-146b were down regulated in AECOPD patients compared with stable COPD patients and HCs. miR-146a and miR-146b are of good values for predicting the risk of AECOPD in HCs with AUC of 0.702 and 0.715. Additionally, miR-146a and miR-146b could distinguish AECOPD from stable COPD patients with AUC of 0.670 and 0.643. In AECOPD patients, levels of miR-146a in AECOPD patients were negatively associated with TNF-α, IL-6, IL-8, and LTE-4 expression. In stable COPD patients, miR-146a expressions were negatively correlated with TNF-α, IL-1β, IL-6, IL-8, and LTE-4 levels. And, the expressions of miR-146b in AECOPD patients were negatively associated with IL-1β and LTB-4 expression. While in stable COPD patients, miR-146b expressions were only negatively correlated with TNF-α level.In conclusion, miR-146a and miR-146b were negatively correlated with inflammatory cytokines, and could be promising biomarkers for predicting the risk of AECOPD in stable COPD patients and healthy individuals.