High prevalence of anal high-grade squamous intraepithelial lesions, and prevention through human papillomavirus vaccination, in young men who have sex with men living with HIV.

Background Men who have sex with men (MSM) are at high risk for HPV-related anal cancer. Little is known about the prevalence of low-grade squamous intraepithelial lesions (LSIL) and the anal cancer precursor, high-grade squamous intraepithelial lesions (HSIL), among young MSM living with HIV (MSMLWH). HPV vaccination is recommended in this group but its safety, immunogenicity and protection against vaccine-type HPV infection and associated LSIL/HSIL have not been studied. Methods 260 MSMLWH 18-26 years-old were screened at 17 U.S. sites for a clinical trial of the quadrivalent (HPV6/11/16/18) HPV (qHPV) vaccine. Those without HSIL were vaccinated at 0, 2, and 6 months. Cytology, high-resolution anoscopy with biopsies of lesions, serology, and HPV testing of the mouth/penis/scrotum/anus/perianus, were performed at screening/month 0, and months 7, 12 and 24. Results Among 260 MSMLWH screened, the most common reason for exclusion was detection of HSIL, in 88/260 (34%). 144 MSMLWH were enrolled. 47% of enrollees were previously exposed to HPV 16. No incident qHPV type-associated anal LSIL/HSIL was detected among men naive to that type, compared with 11.1, 2.2, 4.5, and 2.8 cases/100 person-years for HPV 6/11/16/18-associated LSIL/HSIL, respectively, among those previously exposed to that type. qHPV was immunogenic and safe with no vaccine-associated serious adverse events. Conclusions 18-26 year-old MSMLWH naive to qHPV vaccine types were protected against incident qHPV type-associated LSIL/HSIL. Given their high prevalence of HSIL there is an urgent need to vaccinate young MSMLWH prior to exposure to vaccine HPV types, before initiating sexual activity, and to perform catch-up vaccination.