One Lesion, One Virus: Individual Components of High-Grade Anal Intraepithelial Neoplasia in HIV-Positive Men Contain a Single HPV Type

Olivier Richel, Koen D. Quint, Jan Lindeman, Carel J. M. van Noesel, Maurits N. C. De Koning, Henk A. M. van den Munckhof, Henry J. C. De Vries, Jan M. Prins, Wim G. V. Quint

Background. High-grade anal intraepithelial neoplasia (AIN) is present in many human immunodeficiency virus (HIV)-positive men who have sex with men. The major etiologic factor is infection with an oncogenic human papillomavirus (HPV) genotype. We investigated whether individual components of high-grade AIN are caused by single HPV types.Methods. DNA was isolated from whole-tissue sections of 31 high-grade AIN that were recovered from 21 HIV-positive men who have sex with men. The SPF10 PCR/LiPA25 HPV genotyping system was used for DNA analysis. In whole-tissue sections with multiple HPV types, polymerase chain reaction was repeated in regions of AIN sampled by laser-capture microdissection. The results were compared with HPV types in anal swabs.Results. A single HPV type was observed in 15 (48%) of 31 whole-tissue sections. In an additional 14 whole-tissue sections, 1 HPV type was found in each lesion sample evaluated by laser-capture microdissection. Consequently, in 29 of 31 biopsy specimens (94%), a single HPV type was found in each lesional component studied. Two whole-tissue sections contained collision regions, each with 2 HPV types. HPV16 was presumed to be causative in 14 of 31 biopsy specimens (45%). More than half of the anal swabs did not contain all causative HPV types.Conclusions. Individual components of high-grade AIN are caused by single HPV types (the so-called one lesion, one virus concept). HPV16 is causative in <50% of cases. Anal swabs are not useful for detecting lesion-specific HPV types.