Expression of TNF-α in oral lichen planus treated with fluocinolone acetonide 0.1%

Background: Oral lichen planus (OLP) is a common chronic inflammatory disease involving T cells-mediated immunity. Tumor necrosis factor (TNF)-alpha has been reported to be involved in the disease process. The purpose of this study was to investigate the effect of fluocinolone acetonide in orabase (FAO) 0.1% on the expression of TNF-alpha in patients with OLP. Methods: Eighteen Thai patients with atrophic or erosive OLP were recruited. Biopsy specimens were taken before and 1 month after treatment with FAO 0.1% and sent for histopathologic examination where they were immunohistochemically stained with antibody to TNF-alpha. Twenty normal mucosa specimens were identically processed. Oral squamous cell carcinoma tissue was used as a positive control for TNF-alpha expression, whereas OLP sections without primary antibody were served as negative control. Results: Sixteen of 18 cases (88.89%) of OLP exhibited positive staining for TNF-alpha. Most of the TNF-alpha was observed in the mononuclear cells. Ten cases (55.56%) of OLP demonstrated TNF-alpha expression in keratinocytes. The number of mononuclear cells positive for TNF-alpha before the treatment with FAO 0.1% in orabase was statistically higher than that after the treatment (P = 0.000) and in the normal mucosa (P = 0.000). Moreover, the number of mononuclear cells after treatment with FAO 0.1% in orabase was statistically lower than before the treatment (P = 0.000). Conclusion: Our study exhibited that TNF-alpha may be associated with the immunopathogenesis of OLP in Thai patients and FAO 0.1% had an effect on the reduction of TNF-alpha expression.