Predictive Value of Anti- E6 Oncoprotein (High Risk- Human Papilloma Virus) and p16 Ink4a for Detecting HPV in Oral Epithelial Dysplasia

Abstract

Aim:The aim of this study was to evaluate the expression of human papillomavirus (HPV) in oral potentially malignant disorders (OPMD) and to examine the association of HPV in histological grades of dysplasia using p16 and Anti-E6 oncoprotein immunohistochemistry (IHC). Subjects and methods: This study focused on clinically diagnosed oral potentially malignant disorders. Clinical parameters such as age, gender, habits, occupation, duration, site, and the type of the lesions were examined and the incisional biopsy was done on the selected cases for the histopathological diagnosis. Selected cases of OPMDs were screened immunohistochemically for HPV 16 and HPV 18 (high-risk group) positivity using p16INK4a and Anti-E6 oncoprotein. The immunohistochemical p16 expression was evaluated based on (a) percentage of p16 positive cases and (b) pattern of p16 staining in various grades of OPMD. Results: Anti-E6 oncoprotein (HR-HPV) expression level was only detected in 11 cases (37%), and positive expression of p16 was found in three cases (10%), with variation in cell proportion and intensity. Subsequently, the association between p16 expression level and clinicopathological characteristic factors was analyzed and a significant association was found between age and histopathology. Conclusion: There was an association between HPV and OPMD. Both biomarker tests, HPV E6 and p16 immunocytochemistry had a specific role in the detection of HR-HPV. Anti-E6 immunocytochemistry can be a valuable test with higher specificity for HPV DNA detection in oral epithelial dysplasia without losing sensitivity.