Evaluation of the immunohistochemical expression of DNA damage marker 8-OHdG in different histopathological grades of oral epithelial dysplasia.

OBJECTIVE: The present investigation assessed the advanced oxidative stress end product, 8-hydroxydeoxyguanosine (8-OHdG), in oral epithelial dysplasia using immunohistochemistry (IHC) on tissue samples. MATERIALS AND METHODS: The study used tissue blocks from 40 patients with epithelial dysplasia. The diagnosis was confirmed by reviewing the hematoxylin-eosin slides. Normal mucosa tissue samples (n = 10) formed the control group. The intensity of immunohistochemical reactions was evaluated using light microscopy. The collected data were analyzed statistically using SPSS 26.0 to determine differences between the sample groups at a 5% significance level using Fisher's exact test. RESULTS: Of the 40 leukoplakia with dysplasia samples examined, 5% showed high staining for 8-OHdG antigen, 25% had moderate staining, 37.5% had mild staining, and 43.33% showed no staining. Increased 8-OHdG antigen expression was found in dysplastic tissue samples (P < 0.001) compared to normal tissue samples. Of the mild dysplasia samples, 30% showed mild expression. The remaining 70% had negative 8-OHdG expression. Moderate dysplasia had 13.3% moderate expression, 60% mild expression, and 26.6% showed negative 8-OHdG expression. Of the severe dysplasia samples, 53.3% showed moderate expression, 20% showed mild expression, and 13.3% showed negative 8-OHdG staining. The 8-OHdG marker is intensely expressed in 13.3% of severe dysplasia samples. Compared to mild and moderate dysplasia tissue samples, severe dysplasia had higher 8-OHdG expression (P < 0.01). CONCLUSION: The current investigation suggests that detecting 8-OHdG in potentially malignant oral disorders may be a reliable diagnostic indicator of oxidative DNA degeneration.