Comparative assessment of Chlamydia trichomatis pathogen prevalence, and the determination of host gynaeco-epidemiological and immunological associated risk factors in female infertility

This study investigates the immunopathological responses to Chlamydia trachomatis (Ct) heat shock protein (Ct-Hsp) and their association with infertility. The objective was to explore the prevalence of anti-Ct antibodies and the gyneco-epidemiological risk factors for infertility among women attending a fertility clinic in Zaria, Nigeria, and to analyze the host immune cytokine or Ct-antigen levels in Ct-positive samples for correlation. From December 2022 to January 2024, 215 women (109 infertile and 106 fertile) from Ahmadu Bello University Teaching Hospital participated in this study. Endocervical specimens were tested for Ct-specific IgM and IgG antibodies to identify current and past infections. Additionally, antibodies to Ct-Hsp60, and cytokine levels of IFN-γ and IL-10, were measured using ELISA kits. The overall prevalence of Ct infection was 9.3 %. Past infection, indicated by IgG, was 40 %, while current infection, indicated by IgM, was 25 %. The remaining 35 % of Ct infection were detected by both immunological assay. Among infertile women, primary and secondary infertility prevalence was 41 % and 59 %, respectively. Serum IL-10 levels were significantly higher in Ct-positive infertile women compared to fertile controls. Serum IFN-γ levels were higher in Ct-negative fertile and infertile women than in Ct-positive cases. Serum Ct-Hsp60 levels were significantly higher in Ct-positive fertile women compared to infertile cases. The Th1/Th2 cell ratio was lower in both fertile and infertile women, regardless of Ct status, but fertile controls had a higher Th1/Th2 ratio compared to Ct-positive infertile women. Logistic regression identified significant infertility risk factors: vaginal discharge, age, second marriage, increasing years of childless marriage, and being over 35 years. Protective factors included anti-Ct IgM antibodies, teaching, lower education, and more children. Higher secondary infertility prevalence was linked to family planning history and reactivity to Ct-Hsp60. Ct-positive cases were associated with tubal factor and pelvic inflammatory disease infertility. This study highlights a low overall prevalence of Ct infection but a higher prevalence in women with tubal factor infertility, emphasizing the need for further research on cytokine responses in Ct-associated infertility.