Role of persistent Chlamydia trachomatis infection in development of cervical cancer

Objective: A high-risk type HPV DNA, Chlamydia trachomatis (C. trachomatis) DNA, C. trachomatis-specific IgG and IgA antibodies, and Chlamydial heat shock protein 60 (CHSP60) antibody were examined in healthy women and women with cervical intraepithelial neoplasia and invasive carcinoma, to investigate possible relationships between C. trachomatis infection and cervical cancer. Study design: Sera and cervical cell samples were obtained from 122 healthy women with negative cervical cytology (Group A), 23 women with mild or moderate cervical dysplasia (Group B), 51 women with severe dysplasia and carcinoma in situ (Group C), and 47 women with cervical invasive squamous cell carcinoma (Group D). High-risk HPV DNA was detected using PCR-RFLP and C. trachomatis DNA was detected using PCR. Serum titers of C. trachomatis-specific IgG, IgA and CHSP60 antibodies were measured using ELISA. Results: Mean age for each group ranged from 40.4-48.3 years, with no significant differences between groups. Prevalence of smoking increased with progression of cervical neoplasia. Prevalence of high-risk HPV DNA was significantly higher in Groups C and D than in Groups A and B. No subjects tested were positive for C. trachomatis DNA. Serum antibody titers to CHSP60 and positive rates were higher in Groups C and D than in Groups A and B. Serum antibody titers to C. trachomatis IgA and IgG were also higher in Groups C and D than in Groups A and B. IgG antibody positive rate was significantly higher in Groups C and D compared to Groups A and B. Multiple regression analysis using groups as dependent variables revealed the independent variables of age and CHSP60 as significant risk factors. Conclusions: The finding that CHSP60 antibody is associated with increased risk of cervical cancer suggests that persistent C. trachomatis infection may contribute to cervical neoplasia, and that CHSP60 antibody could offer a significant prognostic marker of high-risk cervical dysplasia.