ABSTRACT
OBJECTIVE: Cytokines have regulatory and leading roles in the immunopathogenesis of oral lichen planus (OLP). Here, we present the findings of a meta-analysis that evaluated serum and salivary interferon-γ (IFN-γ) levels in patients with OLP compared with those in controls and the correlation of this cytokine with the progression of OLP. STUDY DESIGN: Four databases-PubMed, Web of Science, Scopus, and Cochrane Library-were searched, from their start dates to November 2017, for reports in all languages on the effect of OLP on salivary and serum IFN-γ. RESULTS: Eleven studies were included and analyzed in this meta-analysis. The pooled mean difference (MD) values were estimated to be 3.60 pg/mL (Pâ¯=â¯.23) and -0.02 pg/mL (Pâ¯=â¯1.00) for serum and salivary levels of IFN-γ, respectively, in the patients with OLP compared with controls. The pooled MD values were -2.52 pg/mL (Pâ¯=â¯.03) and -2.01 pg/mL (Pâ¯=â¯.20) for serum and salivary IFN-γ levels in the erosive type, respectively, compared with the nonerosive type. CONCLUSIONS: According to the results of meta-analysis, there was no statistically significant differences in IFN-γ levels between the OLP group and the control group both in serum and salivary levels and also between erosive and nonerosive types of OLP at the salivary level; so this cytokine is not considered to have an important role in the pathogenesis or severity of OLP.