HPV-6 molecular variants association with the development of genital warts in men: The HIM Study

Background Human papillomavirus type 6 (HPV-6) and HPV-11 are the etiological agents of approximately 90% of genital warts (GWs). The impact of HPV-6 genetic heterogeneity on persistence and progression to GWs remains undetermined. Methods HPV Infection in Men (HIM) Study participants who had HPV-6 genital swabs and/or GWs preceded by a viable normal genital swab were analyzed. Variants characterization was performed by polymerase chain reaction sequencing and samples classified within lineages (A, B) and sublineages (B1, B2, B3, B4, B5). Country- and age-specific analyses were conducted for individual variants; odds ratios and 95% confidence intervals for the risk of GWs according to HPV-6 variants were calculated. Results B3 variants were most prevalent. HPV-6 variants distribution differed between countries and case status. HPV-6 B1 variants prevalence was increased in GWs and genital swabs of cases compared to controls. There was difference in B1 and B3 variants detection in GW and the preceding genital swab. We observed significant association of HPV-6 B1 variants detection with GW development. Conclusions HPV-6 B1 variants are more prevalent in genital swabs that precede GW development, and confer an increased risk for GW. Further research is warranted to understand the possible involvement of B1 variants in the progression to clinically relevant lesions.