Prevalence of anal human papillomavirus infection and cytologic abnormalities among HIV-infected and HIV-uninfected men who have sex with men.
BACKGROUND
Human papillomavirus (HPV) is responsible for 85% of anal cancers. Recently, anal cancer incidence has been increasing, particularly in men who have sex with men (MSM). Cytology may be a useful tool for the detection of anal precancerous lesions. We assessed the prevalence and determinants of anal HPV infection and cytologic abnormalities among HIV-infected and -uninfected MSM.


METHODS
MSM ≥18-year-old attending an STI clinic in Rome (Italy) were enrolled. Anal cytologic samples were collected in PreservCyt (Hologic) using a Dacron swab. The Linear Array HPV Genotyping Test (Roche Diagnostics) was used for the detection and genotyping of 37 mucosal HPV types. Liquid-based cytological slides were obtained using a ThinPrep2000 processor (Hologic). The morphology of the anal pap-test was classified following the Bethesda 2001 guidelines.


RESULTS
We enrolled 180 HIV-infected (median age 41 years, IQR 33-47) and 438 HIV-uninfected MSM (median age 32 years, IQR: 27-39). Most of the individuals were Caucasian (92.2% and 97.0%, respectively). HPV prevalence, both overall (93.3% vs 72.4%, p<.001) and by high-risk (HR) HPV types (80.5% vs 56.0%, p<.001), was significantly higher among HIV-infected than HIV-uninfected individuals. HPV-multiple infections were evidenced in 48.2% of the HIV-uninfected and 76.1% of the HIV-infected MSM (p<.001). HPV16 was the most prevalent genotype in both groups (23.3% in HIV-positive and 17.6% in HIV-negative MSM). HPV6 and 84 were the most frequent low-risk types in both cohorts. Anal cytologic abnormalities were found in a significantly higher proportion of HIV-infected MSM (46.1% vs 27.9%, p<.001). H-SILs (high-grade squamous intraepithelial lesions) were exclusively observed among the HIV-infected individuals, although at a low prevalence (1.2%).


CONCLUSIONS
A high prevalence of anal HPV infection and cytologic abnormalities was evidenced in both populations. Nonetheless, HIV-infected MSM showed a significantly higher rate of HPV infection and abnormal cytology, confirming that HIV-1 infection poses a significant risk for anal HPV infection as well as for anal cellular abnormalities. Screening for anal cancer, which is currently the most frequent non-AIDS-defining cancer in HIV-positive MSM, should be considered for this population. Moreover, vaccination strategies for the prevention of HPV infection should be taken into account.
Infectious Dermatology and Allergology Unit, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
Alessandra
A
Latini
Infectious Dermatology and Allergology Unit, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
Maria Gabriella
MG
Dona
Pathology Department, Regina Elena National Cancer Institute, IRCCS, Rome, Italy.
Livia
L
Ronchetti
Clinical Pathology and Microbiology DepartmentSan Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
Amalia
A
Giglio
Clinical Pathology and Microbiology DepartmentSan Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
Domenico
D
Moretto
Infectious Dermatology and Allergology Unit, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
Manuela
M
Colafigli
Pathology Department, Regina Elena National Cancer Institute, IRCCS, Rome, Italy.
Valentina
V
Laquintana
Infectious Dermatology and Allergology Unit, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
Mirko
M
Frasca
Clinical Department, National Institute for Infectious Diseases "Lazzaro Spallanzani", Rome, Italy.
Mauro
M
Zaccarelli
Clinical Department, National Institute for Infectious Diseases "Lazzaro Spallanzani", Rome, Italy.
Andrea
A
Antinori
Infectious Dermatology and Allergology Unit, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
Antonio
A
Cristaudo
Infectious Dermatology and Allergology Unit, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
Massimo
M
Giuliani