Detection of human papillomavirus in normal oral cavity in a group of Pakistani subjects using real-time PCR

Since there is evidence that human papillomavirus (HPV) may play some role in oral carcinogenesis, we investigated the presence of HPV in a group of Pakistani subjects with normal oral cavity using real-time PCR analysis. Two-hundred patients attending the Dental Department, Sandaman Provincial Hospital, Balochistan, Pakistan, were recruited. After interview, oral epithelial cells were collected by scraping and subjected to DNA extraction. The HPV-positive DNA samples were further analyzed using primer sets specific for HPV-16 and -18. It was found that out of 200 DNA samples, 192 were PCR-positive for the β-globin gene and these were subsequently examined for the presence of HPV DNA. Among these, 47 (24.5%) were HPV-positive with the virus copy number ranged between 0.43-32 copies per 1 μg of total DNA (9-99 copies per PCR reaction). There were 4 and 11 samples containing HPV-16 and -18, respectively. Additionally, one sample harbored both types of HPV. Among the investigated clinical parameters, smoking habit was associated with the presence of HPV (p = 0.001) while others indicated no significant association. The prevalence of HPV in normal oral cavity in our Pakistani subjects appears to be comparable to other studies. However, the association between the presence of HPV and smoking warrants further investigations whether both of these factors can cooperate in inducing oral cancer in this group of patients.