Frequency of Chlamydia trachomatis infection in cervical intraepithelial lesions and the status of cytological p16/Ki-67 dual-staining

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 the Chlamydia trachomatis infection 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 and Ct-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).