Oral lichen planus (OLP) is a common T cell-mediated chronic inflammatory disease of unknown etiology. Recent increasing evidence indicates that microRNA-146a (miR-146a) plays a vital role in inflammatory diseases and T cell regulation. This study aimed to investigate the expression of miRNA-146a in peripheral blood CD4(+) T cells and local OLP lesions and to evaluate its relationship with clinical forms of OLP. Sixteen patients with OLP were divided into two groups: erosive OLP and nonerosive OLP. The expression of miR-146a was examined by quantitative real-time polymerase chain reaction. The expression of miR-146a in peripheral blood CD4(+) T cells showed no significant difference between OLP group and control group (P > 0.05), and among erosive OLP, nonerosive OLP, and control groups (P > 0.05 for all). The expression in local lesions of the OLP group was significantly higher than that of the control group (P = 0.003), and it was significantly higher in the erosive OLP group than in the non-erosive OLP (P = 0.010) and control groups (P = 0.007). However, miR-146a expression in the nonerosive OLP group did not significantly differ from that in the control group (P > 0.05). These data indicate that miR-146a might be more involved in the local immune disorder of OLP. MiR-146a might be utilized as a candidate biomarker to estimate the severity of OLP.
Keywords: CD4+ T cells; lesion; microRNA-146a; oral lichen planus.