Comparative evaluation of  Ki-67 and P-63 expression in different clinical subtypes  of  Oral Lichen Planus with normal oral mucosa- An immunohistochemical study

Oral Lichen Planus (OLP) is a common chronic inflammatory mucocutaneous disease. Ki-67 is a nuclear antigen expressed during all phases of the cell cycle in proliferating cells, while p63 plays a critical role in the development of stratified epithelium by maintaining proliferative potential, inducing differentiation, and preventing senescence. This study aimed to evaluate the pattern and intensity of Ki-67 and p63 expression in different clinical types of OLP compared to normal oral mucosa. Tissue sections were retrieved from the departmental archives, including 40 patients diagnosed with OLP and 20 normal mucosal tissues as controls. Immunohistochemical staining for Ki-67 and p63 was performed using the EZ-Retriever system V.3 (Bio Genex). Statistical analysis was conducted using Kruskal–Wallis ANOVA and Chi-square tests, with p < 0.05 considered statistically significant. Mild to moderate Ki-67 expression was observed in the basal, parabasal, and spinous layers of plaque-type and reticular OLP, whereas intense expression was seen in erosive OLP with dysplasia (p < 0.05). Similarly, mild to moderate p63 expression was noted in plaque, reticular, pigmented, and bullous OLP, with erosive OLP exhibiting intense expression (p < 0.005). In conclusion, Ki-67 and p63 expression were significantly higher in erosive OLP compared to non-erosive variants. This study provides a preliminary insight into the biological behavior of different OLP clinical variants based on Ki-67 and p63 expression, which may aid in understanding their pathogenesis and malignant transformation potential