title: Cytological Anal Squamous Intraepithelial Lesions Associated with Anal High-Risk Human Papillomavirus Infections among Men Who Have Sex with Men in Northern Thailand.
abstract: BACKGROUND
  Anal cancer, one of human papillomavirus (HPV) related malignancies, has increased in recent decades, particularly among men who have sex with men (MSM) and HIV-infected (HIV+) persons. We aimed to explore the prevalence of anal squamous intraepithelial lesions (ASIL) using Papanicolau (Pap) screening among MSM in northern Thailand and its associated factors.
  
  
  METHODS
  Two hundreds MSM aged ≥18 years reporting receptive anal intercourse in the prior 6 months were recruited from July 2012 through January 2013. Medical history and behavioral data were collected by staff interview and computer-assisted self interview. Anal Pap smear, HPV genotyping, and HIV testing were performed. Two pathologists blinded to HPV and HIV status reported cytologic results by Bethesda classification.
  
  
  RESULTS
  Mean age was 27.2 years (range 18-54). Overall, 86 (43.0%) had ASIL: 28 (14.2%) with atypical cells of undetermined significance (ASCUS), 1 (0.5%) with atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion (ASC-H), 56 (28.4%) with low-grade squamous intraepithelial lesion (LSIL), and 1 (0.5%) with high-grade squamous intraepithelial lesion (HSIL). ASIL was associated by univariate analysis (p ≤0.05) with older age, gender identity other than bisexual (i.e., gay men and transgender women), rectal douching, anal symptoms, genital warts, HIV positivity, and high-risk-HPV infection. However, on multiple logistic regression ASIL was associated only with high-risk HPV type (p = 0.002) and HIV infection (p = 0.01).
  
  
  CONCLUSIONS
  ASIL is quite common in high-risk MSM in northern Thailand and is associated with high-risk HPV types and HIV infection. Routine anal Pap screening should be considered, given the high frequency of ASIL, particularly in the HIV+. High resolution anoscopy (HRA), not done here, should be to confirm PAP smears whose sensitivity and specificity are quite variable. Timely HPV vaccination should be considered for this population.
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Darin
authors.initials: D
authors.lastname: Ruanpeng
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Suwat
authors.identifier: http://orcid.org/0000-0002-3711-7144
authors.initials: S
authors.lastname: Chariyalertsak
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.|Division of Infectious Diseases, Department of Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Quanhathai
authors.initials: Q
authors.lastname: Kaewpoowat
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Taweewat
authors.initials: T
authors.lastname: Supindham
authors.affiliation: Department of Pathology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Jongkolnee
authors.initials: J
authors.lastname: Settakorn
authors.affiliation: Department of Pathology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Kornkanok
authors.initials: K
authors.lastname: Sukpan
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Utaiwan
authors.initials: U
authors.lastname: Utaipat
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Miura
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Natthapol
authors.initials: N
authors.lastname: Kosashunhanan
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Pongpun
authors.initials: P
authors.lastname: Saokhieo
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Radchanok
authors.initials: R
authors.lastname: Songsupa
authors.affiliation: Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Antika
authors.initials: A
authors.lastname: Wongthanee
mesh_terms: D000293:Adolescent; D000328:Adult; D001004:Anus Diseases / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D005260:Female; D005838:Genotype; D018451:Homosexuality, Male / Q000523:psychology / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D065006:Papanicolaou Test; D027383:Papillomaviridae / Q000472:pathogenicity*; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D015995:Prevalence; D012307:Risk Factors; D012725:Sexual Behavior; D065310:Squamous Intraepithelial Lesions of the Cervix / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult