Epidermal growth factor receptor and myeloperoxidase expression in geographic tongue: an observational study.

BACKGROUND: Geographic tongue (GT) is a common oral mucosal lesion that affects the dorsal and lateral surfaces of the tongue and characterized by erythematous areas of papillary atrophy surrounded by peripheral zones. The aim of this study was to evaluate the expression of myeloperoxidase (MPO), epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) in tissue samples from patients with GT compared to control. METHODS: Biopsies specimens from patients with GT (n=10, mean age 48.3 ± 16.7 years) and control subjects (n=3, mean age 59.0 ± 3 years) were evaluated. Immunofluorescence was used to assess the MPO staining intensity of positive cells (i.e. scoring grades 0, 1 and 2). Furthermore, the percentage of EFG and EGFR positive cells in the tongue tissue samples was evaluated by immunofluorescence. RESULTS: Most of the patients with GT (n=6) scored 2 for MPO expression, demonstrating an increased expression of MPO among GT patients compared to controls (p = 0.0266). The expression of EGF positive cells among patients with GT showed no difference compared to controls. In contrast, patients with GT showed a statistically significant low EGFR activity compared to controls (p < 0.0001). CONCLUSION: Patients with GT showed a high MPO activity while low EGFR expression which may explain the underlying inflammatory response and decreased regeneration process in GT.