No differences in caspase-3 and Bax expression in atrophic-erosive vs. reticular oral lichen planus

Background Caspase‐3 (CPP32) and Bax expression levels in oral lichen planus (OLP) lesions are considered reliable markers of apoptosis. The malignant transformation of OLP remains a very controversial matter. The objective of this study was to compare histological and apoptotic phenomena between atrophic‐erosive and reticular forms of OLP. Methods Analysis was conducted of biopsy samples from 18 patients with reticular and 14 with atrophic‐erosive OLP. Conventional histology techniques were used to quantify histological markers of OLP and peroxidase/anti‐peroxidase techniques to determine apoptosis markers caspase‐3 (CPP32) and Bax. Results More Civatte bodies and lymphocyte exocytosis were observed in atrophic‐erosive than reticular OLP samples, without any statistical difference. No statistical significant differences in caspase‐3 expression were found between these OLP forms in suprabasal layer (58.3% vs. 43.8%), basal layer (83.3% vs. 68.8%) or infiltrate (69.2% vs. 46.6%). Bax expression was relatively infrequent, and no differences were observed between atrophic‐erosive and reticular forms. Conclusions The low frequency of apoptotic phenomena (caspase‐3 and Bax) in epithelial cells of OLP may create a favourable substrate for malignant transformation. However, there does not seem to be an association with the clinical form (atrophic‐erosive or reticular).