Plasma levels of miR-155. (A)Plasma levels of miR-155 were detected in in healthy (n=30), allergic rhinitis (AR, n=31), Mild-Mod asthmatic (n=29), and severe asthmatic (n=33) human patients by real-time PCR analysis. (B) Plasma levels of miR-155 were measured in asthmatics with mild-moderate asthma (n=29) or severe asthma (n=33), with or without cockroach allergy (CR- or CR+, respectively). (C) Plasma miR-155 in asthmatics with high or low eosinophils based on the median value in our population (≥200 cells/µl). (D) Proposed model for cockroach allergen-induced ROS generation and miR-155 secretion, which up-regulates COX-2 expression and subsequent Th2/Th17-associated allergic inflammation in allergic asthma.