Prevalence and persistence of HPV-16 molecular variants in the anal canal of men: The HIM study.

BACKGROUND

HPV-16 causes approximately 90% of anal canal (AC) cancers worldwide. This study aimed to evaluate the prevalence and persistence of HPV-16 genetic variants in the AC of men from three different countries (Brazil, Mexico and United States) and to further identify sociodemographic and behavioral factors associated with these infections.

METHODS

Participants from the multinational prospective HPV Infection in Men (HIM) Study who had at least one HPV-16 positive AC swab were included. Characterization into HPV-16 genetic variants was successfully performed by PCR-sequencing in 95.6% (217/227) samples and these were classified into HPV-16 lineages and sublineages.

RESULTS

We observed higher prevalence of lineage A variants, mainly from A1 sublineage, in all countries. Non-A lineage variants were mostly detected in men from Brazil, where higher diversity of sublineage variants was detected during follow-up. Compare to men detected with Non-A HPV-16 lineage variants, men infected with lineage A reported a higher lifetime number of female sexual partners. Finally, a significantly higher prevalence of Non-A lineage variants was observed among men who have sex with men (MSM) with a transient HPV-16 AC infection (p = 0.033), but no significant differences regarding variants lineages and persistence status were observed when stratified by country, self-reported ethnicity or age.

CONCLUSIONS

Our data extend previous reports which indicate that globally HPV-16 variants are unevenly distributed, and contribute further to studies of the natural history of AC HPV infections in men.