Detection of High Risk Human Papilloma Virus (HPV) Genotypes 16/18 in Oral Lesions of Tobacco Chewers in Pakistan

Abstract

Background: The Human Papilloma Virus (HPV) has evolved as a new culprit of malignant and pre malignant oral lesions. The objective of this study was to find out the frequency of HPV and its high risk genotypes in different lesions of oral cavity of tobacco chewers. Methods: From 492 subjects (421 males and 71 females), 20 ml of oral rinse sample was collected after obtaining an informed consent. Normal subjects with no chewing habits (250) including 135 males and 115 females were also taken from same setting. Gentle brushings over the lesions with the help of dental floss brush was done which was left in the oral rinse and stored at 4°C until DNA extraction. DNA was extracted and PCR was performed using HPV consensus primers Gp5+/Gp6+ and HPV 16, 18 specific primers for genotyping. Categorical data was calculated as frequencies and percentages. Results: Oral pre-malignant lesions were present in 421 (86%) males and 71(14%) females having leukoplakia (173, 35%), erythroplakia (60, 12%), submucous fibrosis (192, 39%) and L/E (67, 14%). Total number of HPV positives were 128 (26%), having HPV 16 (13%) and HPV 18 (11%) whereas, 76% had other genotypes. Among Submucous fibrosis 82(46%) were HPV positive. Out of total 128 HPV patients 92% were males and 8% were females. All controls were found to be HPV negative. Conclusion: Frequency of HPV was found high (26%) in oral lesions with HPV16/18 as 13% and 11% respectively. The patients with submucous fibrosis are at greater risk of having HPV. Other HPV genotypes causing premalignant lesions require further investigation.