Circulating miRNAs are Down-regulated in Asthmatic Patients; Case-control Study.

Purpose: Microribonucleic acids (miRNAs) play an important role as non-invasive biomarkers and predictors of inflammatory disease activity. This study aimed to determine differences in expression profiles of miRNAs in patients with asthma compared to healthy controls (HC). Study Design and Methods: In this study, we evaluated a panel of 84 miRNAs in plasma from 3 asthmatic patients and three healthy controls (HC), and we observed decreased levels of miR-17-5p, miR-18a-5p, miR-106b-5p, miR-126-3p, miR-223-3p y miR-374a-5p which were validated in an independent group. Real-time PCR was performed to compare the expression level of each miRNA in a group of 27 asthmatic patients and 27 healthy controls. Results: Correlations between miRNAs and body mass index (BMI) and forced expiratory volume during the first second (FEV1) were also determined. Asthmatic patients had lower levels of miR-17-5p(p=0.026), miR-106-5p (p=0.022), miR-126-3p (p=0.041, and miR-223-3p (p=0.13) than healthy controls. miRNAs did not correlate with BMI and FEV₁. Conclusion: Data suggest that circulating miRNAs described in this study could be employed as biomarkers for asthma prediction.