Increased levels of Th1-inducing cytokines are detected in cervical secretions of women with Chlamydia trachomatis infection limited to their cervix

Abstract Background Chlamydia trachomatis (CT) is the leading bacterial sexually transmitted infection worldwide. CT can ascend to the upper reproductive tract in women, and cause tissue damage resulting in reproductive sequalae. Data from animal and human studies indicate a role for the Th1 cytokine, IFNγ, in protection from infection and disease. Methods We recruited 246 women at high risk for CT infection. Cervical swabs and endometrial biopsies were collected for detection of sexually transmitted pathogens, including CT, by nucleic acid amplification test (NAAT). Cervical secretions collected using cervical sponges were screened for 57 cytokines using multiplex bead arrays. Data were analyzed by logistic regression. Results 92 (37%) women were NAAT+ for CT in only their cervix and 69 (28%) women had CT infection detected at both their cervix and endometrium. Compared to women with endometrial infection, women with only cervical infection had higher levels of CX3CL1 (p<0.05), a potent chemoattractant of T cells and monocytes; CXCL14 (p<0.01), a chemoattractant and activator of dendritic cells, monocytes, and NK cells; and the Th1 inducing cytokine IL-12p70 (p=0.07). Conversely, type I IFN-inducible proteins CXCL9 (p<0.05) and CXCL10 (p<0.01) were significantly increased in women with endometrial infection, compared to women with cervical infection only. Conclusions Th1-associated cytokines in cervical secretions are associated with limitation of infection to the cervix, whereas type I IFN-associated chemokines are associated with endometrial CT infection. These proteins may be used as biomarkers to identify women at increased risk for upper reproductive tract pathology and those who could benefit from enhanced screening.