ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of the peripheral blood retinoid-related orphan receptor gamma t (RORgamma t) and 4-1BB/4-1BBL mRNA in oral lichen planus (OLP) patients.</p><p><b>METHODS</b>The expression levels of peripheral blood' RORyt mRNA and 4-1BB/4-1BBL mRNA of 30 samples of OLP patients and 30 cases of healthy human were detected using real-time fluorescent quantitative-polymerase chain reaction (FQ-PCR) technology.</p><p><b>RESULTS</b>In the OLP group, the expression level of RORgamma t, 4-1BB, 4-1BBL mRNA were higher than those in the control group (P < 0.05). After the conversion of the 2-delta delta CT, the expression levels of three kinds of mRNA in the OLP group were 3.087, 3.320 and 4.005 times of the control group respectively. In the OLP group, the expression levels of RORgamma t mRNA and 4-1BB mRNA had no obvious correlation (P > 0.05), the expression levels of 4-1BB and 4-1BBL mRNA had a positive correlation (r = 0.455 0, P < 0.05).</p><p><b>CONCLUSION</b>The abnormal expression of RORyt, 4-1BB and 4-1BBL mRNA may play certain roles in the pathogenesis of OLP.</p>