Abstract
To determine the value of low-risk human papillomavirus (HPV) PCR to screen for "high-grade anal squamous intraepithelial lesion and anal cancer" (HSIL-plus), rate of patients with low-grade anal squamous intraepithelial lesion (LSIL) progressing to HSIL-plus, and progression-related factors. Prospective, longitudinal study of consecutive MSM-LHIV attended between May 2010 and December 2021 and followed for 43 months (IQR: 12-76). HIV-related variables were gathered at baseline, performing anal cytology for HPV detection/genotyping, thin-layer cytological study, and high-resolution anoscopy (HRA). Follow-up was annual when HRA was normal or LSIL, and post-treatment in cases of HSIL-plus, re-evaluating sexual behavior, viral-immunological status, and HPV infection of anal mucosa. The 493 participants had mean age of 36 years: CD4 nadir < 200 cells/uL in 23.1%, virological failure in 4.1%, and tetravalent HPV vaccine > 5 years earlier in 15%. HSIL-plus was ruled out in patients with monoinfection by low-risk HPV genotype and normal cytology (100% sensitivity, 91.9% specificity, PPV 2.9%, and NPV 100%). Progression from LISL to HSIL-plus occurred in 4.27% of patients within 12 months (IQR: 12-12): risk factors were acquisition of high-risk (HR: 4.15; 95% CI: 1.14-15.03) and low-risk (HR: 3.68 95% CI: 1.04-12.94) HPV genotypes, specifically genotype 6 (HR: 4.47, 95% CI: 1.34-14.91), and history of AIDS (HR: 5.81 95% CI: 1.78-18.92). Monoinfection by LR-HPV genotypes in patients with normal cytology is not associated with anal cancer or precursor lesions. Progression from LSIL to HSIL-plus, observed in <5% of patients, was related to acquisition of HR and LR HPV genotypes, especially 6, and a history of AIDS.