Effects of glucocorticoids on T helper cells balance in oral lichen planus

Abstract

To investigate the effects of dexamethasone on Th1/Th2 cytokines in oral lichen planus. Peripheral blood mononuclear cells (PBMC) were isolated by density gradient centrifugation from OLP patients and healthy controls. PBMC from patients with OLP were stimulated with phytohemagglutinin (PHA) and dexamethasone respectively for 72 h. The concentrations of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) in culture supernatants were determined by ELISA. The mRNA levels for IFN-gamma and IL-4 in culture cells were evaluated using semi-quantitative reverse transcription-polymerase chain reaction. Compared with healthy controls, the levels of IFN-gamma in OLP patients were significantly lower (P < 0.05). The levels of IL-4 were higher, but not statistically significant (P > 0.05). The ratios of IFN-gamma/IL-4 were lower in patients with OLP (P < 0.05). Dexamethasone significantly inhibited the levels of IFN-gamma and IL-4 (P < 0.01). Moreover, IFN-gamma was inhibited significantly more than IL-4. The levels of IFN-gamma and IL-4 mRNA expression in culture cells were consistent with protein production in supernatants. Th2 immune response is predominant in OLP. Dexamethasone is an immunosuppressant inhibiting Th1/Th2 cytokines.