LAUSR

Background Men who have sex with men (MSM) are at high risk of developing human papillomavirus (HPV)-related anal cancer. We compared HPV genotypes in anal tissues (Bx) and anal liquid-based cytology fluid (LBC) from HIV-positive and HIV-negative MSM. Methods Bx (32 normal, 41 low-grade squamous intraepithelial lesions (LSIL) and 22 high-grade squamous intraepithelial lesions (HSIL)), along with LBC from the same visit, were selected from 61 HIV-positive and 34 HIV-negative MSM who enrolled into a prospective cohort in Bangkok, Thailand. HPV genotyping was performed on Bx and LBC. Results Any HPV and high-risk HPV (HR-HPV) prevalence were 63.2% and 60.0% in Bx and 71.6% and 62.1% in LBC, respectively. HIV-positive MSM had higher rates of HR-HPV genotypes detection (70.5% vs. 47.1%, p=0.03) in LBC than HIV-negative MSM. HPV16 (27%) was the most common HR-HPV found in HSIL tissue. In HIV-positive MSM, the frequency of HR-HPV detection increased with histopathologic grading in both Bx and LBC samples. HSIL was associated with the presence of any HR-HPV(OR 7.6 (95%CI 1.8–31.9); P=0.006) in LBC and in Bx((OR 5.6 (95%CI 1.4–22.7); P=0.02). Conclusions Our data strongly support the integration of HR-HPV screening on LBC samples, along with HPV vaccination, into an anal cancer prevention program.