Oral lichen planus may enhance the expression of Th17-associated cytokines in local lesions of chronic periodontitis

Abstract

This study aims to compare the expression levels of interleukin (IL)-17 and IL-23 in local periodontal tissues from patients with both chronic periodontitis and oral lichen planus (CP-OLP), patients with chronic periodontitis (CP) only, patients with oral lichen planus (OLP) only, and healthy controls (HC). The periodontal tissues were collected from 15 CP-OLP patients, 15 CP patients, 15 OLP patients, and 10 healthy controls. Immunohistochemistry (IHC) and real-time quantitative PCR (qPCR) was performed to investigate the protein and mRNA expression level of IL-17 and IL-23 in periodontal lesions from these four groups. IHC statistical analysis showed that the expression level of IL-17- and IL-23p19-positive cells significantly increased in CP-OLP group compared with that in CP (P < 0.01) and OLP groups (P < 0.05), showing intense staining reaction in local lamina propria lesions. Meanwhile, qPCR result showed higher IL-17 mRNA level in CP-OLP compared with that in CP and OLP groups and demonstrated a significant increase than OLP group (P < 0.05). Moreover, it was found that IL-17 mRNA expression level in erosive CP-OLP patients was significantly correlated with probing depth and attachment loss (P < 0.05). This study indicated that there was an increased expression level of IL-17 and IL-23 in periodontal tissues from periodontitis patients with oral lichen planus, which might aggravate the inflammatory response in local lesions. Oral lichen planus and chronic periodontitis may have interaction in disease pathogenesis, while IL-17 detection in local lesions may be helpful in identifying the disease severity in periodontitis patients with oral lichen planus.