Downregulation of TLR-7 receptor in hepatic and non-hepatic patients with lichen planus

Abstract

Background Lichen planus (LP) is an inflammatory disease of the skin and oral mucosa. The association of LP and chronic hepatitis C virus (HCV) is well established, with variable prevalence rates among different populations. Toll-like receptors (TLRs) are key regulators of both the innate response and the adaptive response. However, TLRs also interact with endogenous ligands released by necrotic cells, and this process can intensify autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. Objective To investigate the role of Toll-like receptor-7 (TLR-7) in LP through the detection of TLR-7 protein, and to compare between the expression of TLR-7 protein in HCV-positive and HCV-negative patients with LP. Materials and methods The study included 20 skin biopsies from patients with LP and 10 control biopsies. TLR-7 protein was detected by Western blot analysis. Detection of HCV-specific antibodies in the patient serum was done using ELISA technique. Results Our analysis revealed a significantly lower level of TLR-7 protein in all the LP skin biopsies compared with controls. The expression showed no difference between HCV-positive and HCV-negative patients. Conclusion We concluded that TLR-7 abnormal expression in LP may have an impact on the pathogenesis of the disease. TLR-7 receptor and HCV relationship in patients with LP could not be confirmed by this study. © 2012 The International Society of Dermatology.