Prevalence of Transcriptionally Active HPV16 and HPV18 infection in Anogenital Warts: A Study in Sikkim, India

BACKGROUND: Human papillomavirus (HPV) is the most prevalent sexually transmitted infection globally and is causally related to anogenital and oral cancers, with 311,000 associated deaths recorded in men and women every year. The presence of oncogenic HPV genotypes in anogenital warts is reported by few studies, while many groups have reported an associated higher risk of anogenital and other cancers in patients with anogenital warts. This study aimed to detect HPV16 and HPV18 DNA and mRNA markers in anogenital warts to assess infection and viral persistence. METHOD: A cross-sectional study design was adopted to enroll 50 consenting men and women presenting with anogenital warts at the dermatology clinics of two existing referral hospitals in Sikkim. Samples were processed for DNA and RNA extraction, cDNA conversion, followed by qPCR-based amplification for HPV16 and HPV18 E6/E7 DNA and mRNA. RESULT: High presence of E6/E7 genes of HPV16 and HPV18 with DNA and mRNA was observed in the exfoliated anogenital warts tissue samples, evaluated using quantitative PCR (qPCR). HPV16E6 and HPV18E6 DNA was present in 75.5% (37/49) and 26.6% (13/49) of the samples, while HPV16E6 and HPV18E6 mRNA was present in 62.0% (31/50) and 52.0% (26/50) of the samples, respectively, 18.0% (9/50) of the samples tested positive for HPV16E7 mRNA, while none were positive for HPV18E7 mRNA. CONCLUSION: High prevalence of HPV16 and HPV18 seen in males and females with Anogenital warts in the present study re-emphasizes the significance of including men in HPV screening and vaccination programs, and importance of testing oncogenic HPV genotypes in anogenital warts to improve the overall reduction of clinical manifestations associated with HPV.