Análise da imunoexpressão de 8-Hidroxi-2'-Deoxiguanosina em liquen plano oral

Abstract

The Oral Lichen Planus (OLP) is a chronic immune mediated mucocutaneous disease and relatively common in the oral mucosa. Several researches have been carried out with the intention of identifying pathogens of this lesion, standing out as research that uses oxidative stress biomarkers. Among these biomarkers, there is an 8-hydroxy-2'-deoxyguanosine (8- OHdG), which is generated after oxidative damage in DNA. The aim of this study was to evaluate the oxidative damage to DNA in the OLP through the immunohistochemical expression of 8-OHdG, to verify the possible involvement of this biomarker in the pathogenesis of this lesion. An immunoexpression of 8-OHdG protein was evaluated in a semi-quantitative way in the epithelium of 46 cases of OLP and 17 samples of clinically normal oral mucosa and with statistical analysis data using Kruskall-Wallis and Mann Whitney non-parametric tests. The level of significance was established at 5% (p> 0.05). When analyzing an immunoexpression of 8-OHdG in the erosive and reticular forms of OLP and normal oral mucosa, there was a trend of greater nuclear immunoexpression of 8-OHdG was observed in erosive OLP, compared to reticular OLP and normal oral mucosa. However, the Kruskall-Wallis non-parametric test did not show statistically significant differences between groups (p = 0.088). There was also a trend of greater intensity of marking for 8- OHdG in cases of reticular and erosive OLP, when compared to the normal oral mucosa, although no statistical significance was found (p = 0.085). In relation to symptomatology, greater immunomarking was observed, both cytoplasmic and nuclear (p = 0.004 and p = 0.016, respectively) of 8ÓHdG in symptomatic cases, in comparison with asymptomatic cases. The results of this study indicate a high immunohistochemical expression of 8-OHdG in OLP, suggesting an oxidative stress role in its pathogenesis, which may constitute an additional therapeutic target for this disease.