Abstract: Objective: To detect the expression level of microRNA-155 (miR-155) and to determine the relationship with the imbalance of T-helper 17 cell/regulatory T cell (Th17/Treg) in the patients with cutaneous lichen planus (CLP). Methods: The expression of miR-155, retinoid-acid receptor-related orphan receptor gamma (RORγt), interleukin-17A (IL-17A), forkhead box P3 (Foxp3) and IL-10 in peripheral blood of 33 patients with CLP and 25 normal controls were detected by TaqMan probe. Results: Compared with the normal controls, the expression levels of miR-155, RORγt, Foxp3 and IL-17A were higher and the level of IL-10 expression was lower in the CLP patients with CLP (P＜0.05). The level of miR-155 expression was positively correlated with the expression levels of of RORγt, Foxp3 and IL-17A in the patients with CLP (Ps＜0.001). There was no correlation between the expression level of miR-155 and IL-10. Conclusion: The miR-155-upregulation existed in the CLP patients may be associated with the imbalance of Th17/Treg.

Key words: microRNA-155, lichen planus, T-helper 17 cell, regulatory T cell, interleukin-17A