Predictive Values of Serum Chlamydia trachomatis TroA and HtrA IgG Antibodies as Markers of Persistent Infection in the Detection of Pelvic Adhesions and Tubal Occlusion

Abstract

Chlamydia trachomatis IgG antibody testing (CAT) has been used as a screening test for tubal factor infertility (TFI), but as the CAT is only a marker of a past exposure to C. trachomatis and not of late sequelae, the positive predictive value (PPV) of the test is low. The persistence of C. trachomatis in the upper genital tract has been suggested as one of the key mechanisms in the development of TFI. Serum antibodies against C. trachomatis TroA and HtrA, proteins expressed specifically during persistent infection, have been suggested as novel biomarkers for TFI diagnostics. We studied serum IgG antibody responses against C. trachomatis TroA, HtrA and MOMP in 79 subfertile women, of whom 28 had laparoscopically proven TFI. We confirmed that the accuracy of CAT in diagnosing TFI is low, whereas TroA IgG and HtrA IgG are more accurate tests in detecting tubal occlusion and pelvic adhesions. However, the sensitivity and negative predictive value (NPV) of TroA IgG and HtrA IgG are still too low to justify their use as a screening test in clinical practice. Individual immunogenetic profiles combined with TroA and HtrA antibody responses might identify women with the highest risk for developing late complications after C. trachomatis infection.

Sexually Transmitted Infections and Risk of Epithelial Ovarian Cancer: Results From the Finnish Maternity Cohort

“…Primary antibodies of interest for CT were pGP3, noted as a “gold standard” marker of ever infection [ 28 ], and cHSP60, a potential marker of persistent infection [ 29 ]. HtrA and TroA were evaluated as hypothesized markers of CT-related tubal damage [ 30 ]. Antibodies to L1 of HPV-16 and HPV-18 were deemed indicative of HPV-16 and/or -18 exposures [ 31 ].…”

Intranasal delivery of Salmonella OMVs decorated with Chlamydia trachomatis antigens induces specific local and systemic immune responses

“… 26–29 Chlamydial HtrA expression is upregulated in the persistence phase and serves as a clinical marker for detection of infection. 4 , 30 , 31 The endoprotease activity of HtrA can be inactivated by altering the active site serine (S) at residue 247 to alanine (A), generating a proteolytically inactive variant that is safe for vaccine applications. 32 …”