Immunological Markers of Chlamydia trachomatis Infection in Epithelial Ovarian Cancer

Background/aim: Pelvic inflammatory disease (PID) is a risk factor for epithelial ovarian cancer (EOC). Chlamydia trachomatis infection, a major cause of PID, may persist in some women. Serum IgG antibodies to chlamydial TroA and HtrA are more common in ascending or repeat chlamydial infection than in uncomplicated infection. The aim of this study was to explore the role of C. trachomatis infection in EOC by analyzing chlamydial TroA, HtrA and major outer membrane protein (MOMP) IgG serum antibody responses.

Patients and methods: The study is based on the review of Oulu University Hospital medical records of 162 women diagnosed with EOC between March 2008 and May 2018. Serum IgG antibody responses to recombinant C. trachomatis TroA, HtrA and MOMP were analyzed using enzyme-linked immunoassay. Complete response to the first line therapy and the three-year survival were the study endpoints.

Results: Altogether, 16.7%, 11.1% and 12.3% women were C. trachomatis TroA, HtrA and MOMP IgG positive, respectively. Women with these antibodies were more likely to have a complete response to the first-line treatment, compared to women without these antibodies (63.0% vs. 34.1% for TroA IgG, 50.0% vs. 37.5% for HtrA IgG and 50% vs. 37.3% for MOMP IgG, respectively). The presence of these antibodies predicted better three-year survival.

Conclusion: Women with EOC and positive markers of persistent C. trachomatis infection have better response to the first-line treatment and seem to have better three-year survival.