title: Chlamydia trachomatis and risk of cervical intraepithelial neoplasia grade 3 or worse in women with persistent human papillomavirus infection: a cohort study.
abstract: OBJECTIVE
  Some studies suggest that Chlamydia trachomatis (CT) enhances cervical carcinogenesis; however, a possible confounding effect of persistent human papillomavirus (HPV) infection was not addressed. We examined the potential role of CT infection in the development of subsequent cervical intraepithelial neoplasia grade 3 or worse (CIN3+) in women with prevalent HPV infection and in a subgroup of women with persistent HPV infection.
  
  
  METHODS
  Participants in this population-based cohort study underwent a structured interview, including history of CT infection, and subsequently cervical exfoliated cells were obtained for HPV DNA and CT DNA testing. Women with high-risk HPV DNA infection and no prevalent cervical disease constituted the overall study population (n=1390). A subgroup of women with persistent HPV infection (n=320) was also identified. All women were passively followed for development of cervical lesions in the national Pathology Data Bank. HRs and 95% CIs for CIN3+ during follow-up (up to 19 years) were estimated in an accelerated failure time model.
  
  
  RESULTS
  Women who reported more than one CT infection had a statistically significantly increased risk of CIN3+ (high-risk HPV-positive, HR=2.51, 95% CI 1.44 to 4.37) (persistent HPV infection, HR=3.65, 95% CI 1.53 to 8.70). We found no association between CT DNA and subsequent risk of CIN3+ among women who were HPV-positive or had a persistent HPV infection at baseline.
  
  
  CONCLUSIONS
  Repeated CT infections increased the risk of CIN3+ among women with prevalent as well as persistent high-risk HPV infection.
authors.affiliation: Unit of Virus, Lifestyle, and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Kirsten E
authors.initials: KE
authors.lastname: Jensen
authors.affiliation: Unit of Virus, Lifestyle, and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Louise T
authors.initials: LT
authors.lastname: Thomsen
authors.affiliation: Unit of Statistics, Bioinformatics and Registries, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Sven
authors.initials: S
authors.lastname: Schmiedel
authors.affiliation: Unit of Statistics, Bioinformatics and Registries, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Frederiksen
authors.affiliation: Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Bodil
authors.initials: B
authors.lastname: Norrild
authors.affiliation: Laboratory for Molecular Diagnostics, Department of Medical Microbiology and Pathology, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands.
authors.forename: Adriaan
authors.initials: A
authors.lastname: van den Brule
authors.affiliation: Medical Virology, Section of Experimental Virology, University Hospital of Tübingen, Tübingen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Iftner
authors.affiliation: Unit of Virus, Lifestyle, and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark Gynecologic Clinic, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Kjær
mesh_terms: D000328:Adult; D002690:Chlamydia Infections / Q000453:epidemiology*; D002692:Chlamydia trachomatis / Q000235:genetics*; D015331:Cohort Studies; D004269:DNA, Bacterial / Q000032:analysis*; D004279:DNA, Viral / Q000032:analysis*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D052162:Human papillomavirus 16 / Q000235:genetics; D052161:Human papillomavirus 18 / Q000235:genetics; D058952:Human papillomavirus 31 / Q000235:genetics; D006801:Humans; D060787:Neoplasm Grading; D027383:Papillomaviridae / Q000235:genetics*; D030361:Papillomavirus Infections / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology* / Q000473:pathology; D014626:Vaginal Smears; D055815:Young Adult; D002578:Uterine Cervical Dysplasia / Q000453:epidemiology* / Q000473:pathology
chemical_list: D004269:DNA, Bacterial; D004279:DNA, Viral
keywords: Cervical Neoplasia; Chlamydia Trachomatis; HPV