Follicular fluid antibodies to Chlamydia trachomatis and human heat shock protein-60 kDa and infertility in women

Associations between microbial presence in follicular fluid with IVF outcomes: a systematic review and meta-analysis

PURPOSE

The aim of the study was to synthesize disparate studies to investigate potential impact of microbial presence in FF of infertile women on IVF outcomes.

METHODS

Following preliminary searches to find medical subject heading (MeSH) terms plus free terms, a systematic search was performed in the PubMed, Cochrane Library, Embase, Web of Science, and Clinicaltrials.gov databases from January 10, 2022, to July 5, 2023. Data collected for each study were analyzed using RevMan 5.4 software available on the Cochrane website.

RESULTS

After correcting for contamination from the vagina, the FFs of 289 women were detected positively by microbial culture and identification, ELISA, and IPA. The pregnancy rate of the FF-positive group was significantly lower than the FF-negative group (19.7% vs. 32.2%) and (OR: 0.57, 95% CI: 0.28-1.14, P=0.11; I2=56%) while the fertilization rate was almost equal (60.0% vs. 62.0%) and (OR: 1.03, 95% CI: 0.88-1.20, P=0.72; I2=0%). Evidence quality was very low.

CONCLUSIONS

The different species of microorganisms in FF of infertile women may have different effects on IVF outcomes. The Lactobacillus spp. may have a positive effect, while other microorganisms may have the opposite effect.

SARS-CoV-2 infection negatively affects ovarian function in ART patients

Several organs, such as the heart, breasts, intestine, testes, and ovaries, have been reported to be target tissues of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To date, no studies have demonstrated SARS-CoV-2 infection in the female reproductive system. In the present study, we investigated the effects of SARS-CoV-2 infection on ovarian function by comparing follicular fluid (FF) from control and recovered coronavirus disease 2019 (COVID-19) patients and by evaluating the influence of these FF on human endothelial and non-luteinized granulosa cell cultures. Our results showed that most FFs (91.3%) from screened post COVID-19 patients were positive for IgG antibodies against SARS-CoV-2. Additionally, patients with higher levels of IgG against SARS-CoV-2 had lower numbers of retrieved oocytes. While VEGF and IL-1β were significantly lower in post COVID-19 FF, IL-10 did not differ from that in control FF. Moreover, in COV434 cells stimulated with FF from post COVID-19 patients, steroidogenic acute regulatory protein (StAR), estrogen-receptor β (Erβ), and vascular endothelial growth factor (VEGF) expression were significantly decreased, whereas estrogen-receptor α (ERα) and 3β-hydroxysteroid dehydrogenase (3β-HSD) did not change. In endothelial cells stimulated with post COVID-19 FF, we observed a decrease in cell migration without changes in protein expression of certain angiogenic factors. Both cell types showed a significantly higher γH2AX expression when exposed to post COVID-19 FF. In conclusion, our results describe for the first time that the SARS-CoV-2 infection adversely affects the follicular microenvironment, thus dysregulating ovarian function.

Seropositivity for the human heat shock protein (Hsp)60 accompanying seropositivity for Chlamydia trachomatis is less prevalent among tubal ectopic pregnancy cases than individuals with normal reproductive history

OBJECTIVES

To investigate the role of anti-human heat shock protein 60 (hHsp60) antibody positivity in the pathogenesis of ectopic pregnancy, following Chlamydia trachomatis (CT) infection.

STUDY DESIGN

In a case-control study, serological tests for anti-hHsp60 were performed in ectopic pregnancies (study group) and parturients with normal reproductive histories (control group). All participants in both groups were CT IgG(+). hHsp60 IgG(+) prevalences were compared between the two groups, by semiquantitative ELISA. Data were evaluated using nonparametric and parametric tests and multivariable regression.

RESULTS

After an initial pilot study, two groups were formed: 63 ectopic gestations (study group) and 95 normal parturients (control group), all CT IgG(+). Blood samples from all cases were tested for anti-hHsp60 IgG. Age, gravidity, and practising contraception were higher in the control group, while a history of pelvic infections were more common in the study group. Hsp60 IgG(+) was found to be significantly higher in the control group (63/95, 66.3%) compared to study group (30/63, 47.6%). Regression analysis revealed anti-hHsp60 positivity was an independent factor delineating the two groups.

CONCLUSION

Immunity to hHsp60 is less common in CT IgG(+) ectopic pregnancies than CT IgG(+) fertile subjects without a history of ectopic pregnancies. Hence, our findings suggest that hHsp60 seropositivity may decrease the probability of an ectopic gestation in subjects with previous CT infections.

Tubal factor infertility is associated with antibodies against Chlamydia trachomatis heat shock protein 60 (HSP60) but not human HSP60

BACKGROUND

Serum antibodies against major outer membrane protein (MOMP) and heat shock protein 60 (HSP60) from Chlamydia trachomatis are correlated with sequelae following infection. Since bacterial and human HSP60 share considerable sequence homology, cross-reactivity to human HSP60 is suggested as being involved in tubal factor infertility (TFI). The aim was to investigate whether antibodies to human HSP60 are associated with TFI, and to evaluate antibody testing in TFI diagnosis.

METHODS

Serum levels of antibodies against chlamydial MOMP and HSP60 from C. trachomatis, Salmonella enterica Enteritidis, Campylobacter jejuni and human HSP60 were analysed by enzyme-linked immunosorbent assay in three groups of infertile women: women with TFI (n = 70), controls with normal fallopian tubes (control group 1, n = 92) and a subgroup of women with normal fallopian tubes and sero-positive for either chlamydial MOMP or chlamydial HSP60 (control group 2, n = 28).

RESULTS

Serum levels of immunoglobulin (Ig)G1 and IgG3 antibodies against MOMP and HSP60 from C. trachomatis were elevated in patients with TFI compared with non-TFI individuals (group 1; P < 0.001), while levels of IgG3 against MOMP and IgG1 against HSP60 were higher in the TFI group compared with control group 2 (P = 0.04 and P = 0.03, respectively). Levels of antibodies against human HSP60 did not differ between groups.

CONCLUSIONS

Our findings confirm an association between TFI and antibodies to MOMP and HSP60 from C. trachomatis, suggesting antibody testing as a supplement in TFI diagnosis. No connection was observed between TFI and antibodies to human HSP60, pointing to an infectious rather than an autoimmune inflammation as the cause of TFI.

Detection of follicular fluid and serum antibodies by protein microarrays in women undergoing in vitro fertilization treatment

A protein microarray serological assay was used to assess the antibody profile of 102 women subjected to in vitro fertilization treatment. The studies were conducted on pairs of serum and follicular fluid samples, collected from each woman on the same day at the time of oocyte recovery. The samples, stored as frozen aliquotes, were assessed by both microarray and ELISA. Follicular fluids and sera were screened to detect the presence of specific IgG and IgM antibodies against seven vertically transmitted pathogens. The IgG reactivity of follicular fluids closely mirrored that of serum in all the patients and for all the antigens, with an agreement of more than 85%. IgM antibodies were undetectable in follicular fluids. The antibody patterns were subsequently related to the biological and clinical outcomes of in vitro fertilization cycles. The results showed that varicella zoster virus (VZV) IgG positive women and cytomegalovirus (CMV) IgG negative women had on average a higher number of inseminated, good quality oocytes compared to VZV IgG negative and CMV IgG positive women. In addition, the rate of successful embryo transfers was significantly higher in Toxoplasma gondii IgG negative women than in their positive counterparts. Overall, the microarray was proven to be a suitable tool for detecting analytes in follicular fluids, therefore supporting its application in a wide spectrum of investigations.

Chlamydia trachomatis-specific heat shock proteins 60 antibodies can serve as prognostic marker in secondary infertile women

BACKGROUND

The magnitude of reproductive morbidity associated with sexually transmitted Chlamydia trachomatis infection is enormous. A predictive serological test for upper genital tract infection would be a desirable diagnostic tool as C. trachomatis infection may lead to various immunopathological sequelae such as infertility, or ectopic pregnancy.

MATERIALS AND METHODS

Female patients (n = 198) attending gynecology outpatient department of Safdarjung hospital were enrolled for the study and clinically characterized into four groups on the basis of their symptoms; discharge, chronic cervicitis, primary and secondary infertility. Serological detection of C. trachomatis was done by ELISA using specific peptide sequences of major outer membrane protein (MOMP), Chlamydia heat shock protein (cHSP60 and 10).

RESULTS

Significant high seropositivity to chlamydial anti-cHSP60 antibodies were detected in patients with secondary infertility. A significant percent of chlamydial reinfection was observed in patients having secondary infertility (82.6%; p < 0.01) and chronic cervicitis (64.28%; p < 0.05). Considering IgG MOMP ELISA as a test standard, anti-cHSP60 antibodies showed higher sensitivity (90.91%) and specificity (89.47%) than cHSP10 ELISA (75.6% and 73.87%) in the secondary infertile group. Further anti-cHSP60 antibodies' detection had a sensitivity of 67.33% and a specificity of 90.67% in secondary infertile women when compared with DFA and PCR.

CONCLUSIONS

Our data suggest that detection of anti-cHSP60 antibodies would help in early prognosis of immunopathological sequelae in C. trachomatis-infected women and thereby in instituting appropriate therapy for controlling C. trachomatis infection at an early stage.

Chlamydia trachomatis in subfertile couples undergoing an in vitro fertilization program: a prospective study

OBJECTIVES

The objectives were to estimate the prevalence of Chlamydia trachomatis infection in subfertile couples and to study the relationship between markers of C. trachomatis infection and male infertility as well as pregnancy rates after in vitro fertilization (IVF).

STUDY DESIGN

All consecutive couples consulting for infertility and IVF in Pellegrin Hospital were screened for C. trachomatis by direct (PCR test) and serological methods.

RESULTS

Two hundred and seventy-seven couples were included in the study (mean age in years: 35 for men, 32 for women; mean duration of infertility: 4 years). The most frequent indication for IVF was tubal factor in 33%, endometriosis in 6%, dysovarian function in 12%, male infertility in 36% and others in 13%. C. trachomatis PCR was positive in 1.2% of men, 95% confidence interval (CI95%): (0.2%; 3.3%) and in 2.7% of women, CI95%: (1.1%; 5.5%). When combining all chlamydial markers, 17.3% of men, CI95%: (12.7%; 22.8%) and 20.4% of women, CI95%: (15.6%; 25.9%) had at least one positive marker. The presence of positive markers was not associated with altered semen characteristics. Couples with positive markers had a pregnancy rate of 23.1% (12 out of 52) compared with 20.2% (24 out of 119) among those with negative markers.

CONCLUSION

In this population, the presence of past or current C. trachomatis infection was associated with neither semen characteristics nor outcome of IVF in subfertile couples.

Sustained Interleukin-6 and Interleukin-8 Expression Following Infection with Chlamydia trachomatis Serovar L2 in a HeLa/THP-1 Cell Co-culture Model

Chlamydia trachomatis, an intracellular obligate bacterium, remains responsible for a large spectrum of disorders that can progress to chronic diseases, resulting in severe sequelae, such as tubal infertility and blindness. These sequelae may be due to deleterious immune responses induced by repeated or persistent infections. By initiating and regulating inflammation as well as immune responses, pro-inflammatory cytokines secreted by local infected epithelial and immune cells, such as monocytes, may play an essential role in immunity and in the immunopathogenesis of chlamydial diseases. In this study, we mimicked the in vivo interaction between epithelial cells and monocytes by co-culturing epithelial-like HeLa cells with monocyte-like THP-1 cells. Pro-inflammatory cytokines [interleukin-beta (IL-1beta), IL-6, IL-8, IL-10, IL-12p70 and tumour necrosis factor-alpha (TNF-alpha)] were measured by multiplexed cytometric bead array assay over a period of 18 days. We observed that pro-inflammatory cytokine secretion was augmented after C. trachomatis infection in HeLa and THP-1 cells. However, this heightened secretion was subsequently reduced. When infected HeLa cells were co-cultured with THP-1 cells, IL-6 and IL-8 secretion was sustained, IL-1beta expression followed a bell-shaped curve and IL-10, IL-12p70 and TNF-alpha synthesis was down regulated. IL-6 and IL-8 may be involved in the immunopathogenesis of chronic chlamydial infections. We also observed that throughout C. trachomatis persistence induced by doxycycline (Dox) treatment, IL-1beta, IL-6, IL-8 and TNF-alpha expression was reduced, whereas the synthesis of IL-10 and IL-12p70 remained unchanged but not sustained. Thus, during chlamydial persistence infection evoked by treatment with Dox, none of the tested cytokines showed sustained expression.