title: Frequency ofChlamydia trachomatisinfection in cervical intraepithelial lesions and the status of cytological p16/Ki-67 dual-staining.
abstract: BACKGROUND
  Chlamydia trachomatis(Ct) is not a disease subject to mandatory reporting in Brazil, and the prevalence rate of this genital infection varies according to the region in which studies are conducted, as well as by the detection technique employed. Ct has been associated with persistence of Human papillomavirus (HPV) infection and the facilitation of cervical carcinoma development. We evaluated theChlamydia trachomatisinfection and its association with cytology, p16/Ki-67 dual-stained cytology and cervical intraepithelial lesions status in a screening cohort in Brazil.
  
  
  METHODS
  This was a cross-sectional study of 1481 cervical samples from asymptomatic women aged 18 to 64. Samples were collected for liquid-based cytology and Ct detection by polymerase chain reaction. p16/Ki-67 double staining was performed on samples with abnormal cytology. Statistical analysis was by chi-square and likelihood-ratio tests. Odds ratio (OR) and 95% confidence intervals (95% CI) were determined.
  
  
  RESULTS
  The frequency of Ct was 15.6% and its presence was not associated with detection of p16/Ki-67 [OR = 1.35 (0.5-3.4)]. There was also no association between abnormal cervical cytology andCt-positivity [OR = 1.21 (0.46-3.2)]. Associations were observed between p16/Ki-67 and high-grade lesions detected by cytology and in biopsies [OR = 3.55 (1.50-8.42) and OR = 19.00 (0.6-7.2), respectively].
  
  
  CONCLUSIONS
  The asymptomatic women in our study had a high frequency of Ct infection but this was not associated with p16/Ki-67 detection in samples with abnormal cytology. The expression of p16/Ki-67 was highest in women with high-grade CIN (p= 0.003).
authors.affiliation: Division of Gynecologic Clinic, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: R
authors.identifier: 0000-0002-5108-924X
authors.initials: R
authors.lastname: Robial
authors.affiliation: Laboratory of Medical Investigation (LIM) 14, Faculty of Medicine, University of São Paulo, São Paulo, Brazil ; Molecular Oncology Research Center, Barretos Cancer Hospital, Pio XII Foundation, Barretos, Brazil ; Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal ; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Longatto-Filho
authors.affiliation: Leonor M De Barros Hospital - Secretaria de Saúde de São Paulo, São Paulo, Brazil.
authors.forename: C M
authors.initials: CM
authors.lastname: Roteli-Martins
authors.affiliation: Federal University of Pelotas - Pelotas, Rio Grande do Sul, Brazil.
authors.forename: M F
authors.initials: MF
authors.lastname: Silveira
authors.affiliation: Federal University of Pelotas - Pelotas, Rio Grande do Sul, Brazil.
authors.forename: D
authors.initials: D
authors.lastname: Stauffert
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: G G
authors.initials: GG
authors.lastname: Ribeiro
authors.affiliation: Division of Gynecologic Clinic, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: I M
authors.initials: IM
authors.lastname: Linhares
authors.affiliation: Division of Gynecologic Clinic, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Tacla
authors.affiliation: Discipline of Infectology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Zonta
authors.affiliation: Division of Gynecologic Clinic, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: E C
authors.initials: EC
authors.lastname: Baracat
keywords: Cervical cancer; Chlamydia; Immunocytochemistry; ki 67