Salivary and serum interleukin-18 in patients with oral lichen planus: a study in an ethnic Chinese population.

The purpose of this study was to investigate the potential pro-inflammatory role of the cytokine interleukin (IL-18) in oral lichen planus (OLP) so as to provide a reliable and early indicator for the diagnosis of OLP. One hundred three ethnic Chinese patients with OLP were enrolled in this study, as were 48 age- and sex-matched controls. IL-18 concentrations in serum and saliva were screened by enzyme-linked immunosorbent assay. The protein content was expressed as picograms per milliliter. OLP patients showed a high-level of IL-18 expression profile in serum compared with the control group (OLP = 21.32 ± 8.26 pg/mL, control = 12.29 ± 5.11 pg/mL, P < 0.05), and the saliva partner had significantly higher concentrations of IL-18 compared to the control (OLP = 20.12 ± 5.78 pg/mL, control = 15.60 ± 4.17 pg/mL, P < 0.05). In patients with OLP, serum and salivary IL-18 are elevated, correlating with the severity of illness. These findings may be considered to improve the predictive or prognostic values of inflammatory cytokines for OLP and also to design possible novel therapeutic approaches.