Abstract
Background Alopecia areata (AA) is an immune mediated disorder that attacks hair follicles with unknown pathophysiology. MicroRNAs (miRNAs) are small noncoding RNA molecules, and their aberrant expression or function has been involved in different autoimmune conditions. Objectives We aimed at exploring the association between some miRNAs lesional expression and AA pathogenesis by measurement of miRNAs-155, 146a, and 203 expression levels in the lesional skin from patchy AA patients and to evaluate their relation with the studied parameters. Subjects and Methods Skin expression levels of miRNAs-155, 146a, and 203 were evaluated in 50 patients with patchy AA and 25 healthy controls using reverse transcriptase-quantitative PCR (RT-qPCR). The activity and severity of alopecia were assessed according to AA Investigational Assessment Guidelines criteria. Results Studied patients showed significant up-regulation of miRNAs-203, 146a, and 155 lesional tissue expression levels when compared to control group (p < 0.05 each). Only miRNA-146a skin expression level was significantly higher in patients with multiple lesions (p < 0.001). However, patients with active AA had significantly higher tissue expression levels of the investigated miRNAs than those with inactive disease (P 0.001, 0.009, and 0.001, respectively). Conclusions Investigated miRNAs seem to be role players in AA pathogenesis and may be considered potential indicators of disease activity. However, more research is needed to clarify their accurate role and clinical importance.