[Study on the expression and potential effect of PD-L1mRNA and PD-L2mRNA in oral lichen planus].

Purpose: To study the expression of PD-L1 and PD-L2mRNA in oral lichen planus(OLP) patients' peripheral blood and focal mucosa, and the different expression of target molecules in gene level in different clinical and pathological OLP groups.

Methods: The expression of PD-L1 and PD-L2 mRNA in OLP patients, which included 35 reticular and 25 atrophic-erosive OLP patients, 38 cases without dysplasia and 22 cases with dysplasia, was examined by real-time PCR. Peripheral blood and mucosa from 10 volunteers were used as control. All the results were analysed with Wilcoxon test by SAS.6.12 software package.

Results: The expression of PD-L2mRAN, but not PD-L1, was significantly higher in oral mucosa of OLP patients (P<0.01), while decreased in OLP patients' peripheral blood (P=0.0415). The gene expression of PD-L2 differed between different clinical types, and had highly significant correlation between the OLP patients' focal mucosa and peripheral blood(r=0.6976, P<0.0001).

Conclusions: PD-L2 may have some potential effect on the pathogenesis of OLP at systemic and local level.