title: Order of HPV/Chlamydia infections and cervical high-grade precancer risk: a case-cohort study.
abstract: Interactions of carcinogenic human papillomaviruses (most notably HPV types 16/18/31/33/45), and HPV6 or Chlamydia trachomatis are not well understood. We have used seroconversions to study effects the order of these infections has on the risk of high-grade cervical precancer. In a cohort of 94,349 Finnish women with paired sera from consecutive pregnancies within an average of 2.4 years, 490 were diagnosed with cervical CIN3/AIS. Serum antibodies to HPV6/16/18/31/33/45 and C. trachomatis were measured in paired sera of the cases and a subcohort of 2,796 women with a minimum of two pregnancies. HPV16-adjusted rate ratios (RR) and confidence intervals were estimated by stratified Cox model. Compared to dual seropositivity already at the first serum sampling, RRs related to HPV6 seropositivity before and after HPV31 seroconversion were 0.4 (95% CI 0.0, 4.4) and 10 (95% CI 1.8, 57). Furthermore, RR related to seroconversions of both HPV18/45 and C.trachomatis between the consecutive pregnancies was 28 (95% CI 4.3, 190). Virtually concomitant HPV18/45 and C.trachomatis infections are associated with very high CIN3 risk.
authors.affiliation: Institute for Statistical and Epidemiological Cancer Research, Finnish Cancer Registry, Helsinki, Finland. tapio.luostarinen@cancer.fi
authors.forename: Tapio
authors.initials: T
authors.lastname: Luostarinen
authors.forename: Proscovia B
authors.initials: PB
authors.lastname: Namujju
authors.forename: Marko
authors.initials: M
authors.lastname: Merikukka
authors.forename: Joakim
authors.initials: J
authors.lastname: Dillner
authors.forename: Timo
authors.initials: T
authors.lastname: Hakulinen
authors.forename: Pentti
authors.initials: P
authors.lastname: Koskela
authors.forename: Jorma
authors.initials: J
authors.lastname: Paavonen
authors.forename: Heljä-Marja
authors.initials: HM
authors.lastname: Surcel
authors.forename: Matti
authors.initials: M
authors.lastname: Lehtinen
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002690:Chlamydia Infections / Q000453:epidemiology* / Q000276:immunology; D002692:Chlamydia trachomatis / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D027383:Papillomaviridae / Q000276:immunology; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000276:immunology; D011230:Precancerous Conditions / Q000453:epidemiology*; D012307:Risk Factors; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology*
chemical_list: D000907:Antibodies, Bacterial; D000914:Antibodies, Viral
keywords: Chlamydia trachomatis; case-cohort study; cervical precancer; human papillomavirus; order of infections