Significance of positive Chlamydia serology in women with normal-looking Fallopian tubes

Proteome array of antibody responses to Chlamydia trachomatis infection in nonhuman primates

AIMS

Nonhuman primates have been used to investigate pathogenic mechanisms and evaluate immune responses following Chlamydia trachomatis inoculation. This study aimed to systemically profile antibody responses to C. trachomatis infection in nonhuman primates.

MATERIALS AND METHODS

Sera were obtained from 4 pig-tailed and 8 long-tailed macaques which were intravaginally or ocularly infected with live C. trachomatis organisms, and analyzed by C. trachomatis proteome array of antigens.

KEY FINDINGS

The sera from 12 macaques recognized total 172 C. trachomatis antigens. While 84 antigens were recognized by pig-tailed macaques intravaginally infected with serovar D strain, 125 antigens were recognized by long-tailed macaques ocularly infected with serovar A, and 37 antigens were recognized by both. Ocular inoculation with virulent A2497 strain induced antibodies to more antigens. Among the antigens uniquely recognized by A2497 strain infected macaques, outer membrane complex B antigen (OmcB) induced robust antibody response. Although macaques infected by less virulent A/HAR-13 strain failed to develop antibodies to OmcB, reinfection by A2497 strain induced high levels of antibodies to OmcB.

SIGNIFICANCE

Proteome array has revealed a correlation of chlamydial infection invasiveness with chlamydial antigen immunogenicity, and identified antibody responses to OmcB potentially as biomarkers for invasive infection with C. trachomatis.

Chlamydia trachomatis-induced cell-mediated and humoral immune response in women with unexplained infertility

PROBLEM

What is the role of past Chlamydia trachomatis infection in unexplained infertility?

METHOD OF STUDY

This is a prospective study of the impact of past C. trachomatis infection on pregnancy rates in 96 women with unexplained infertility. Both humoral and cell-mediated immune responses (CMI) against C. trachomatis were studied. Serum C. trachomatis IgG antibodies were analyzed using major outer membrane protein (MOMP) peptide-based ELISA. CMI was studied by lymphocyte proliferation (LP) assay in vitro. Data on given fertility treatment, time to pregnancy, and pregnancy outcome were collected.

RESULTS

Altogether, 11.5% of the 96 women had C. trachomatis IgG antibodies. LP response to C. trachomatis was positive in 62.9% women. The overall pregnancy rate or live birth rate did not differ by the presence of antichlamydial antibodies or CMI against C. trachomatis. Time to spontaneous pregnancy was longer among C. trachomatis sero-positive women than among sero-negative women (2.9 years vs 2.0 years, P = .03).

CONCLUSION

Past chlamydial infection does not play a major role in unexplained infertility. Women with unexplained infertility and positive immune response to C. trachomatis do not have reduced pregnancy rates, but time to spontaneous pregnancy is longer among C. trachomatis IgG sero-positive women than among sero-negative women.

Chlamydia trachomatis immunoglobulin G3 seropositivity is a predictor of reproductive outcomes in infertile women with patent fallopian tubes

OBJECTIVE

To determine if Chlamydia trachomatis (C. trachomatis) seropositivity, as detected by the C. trachomatis elementary body (EB)-based enzyme-linked immunosorbent assay [EB ELISA] predicts pregnancy and pregnancy outcome among infertile women with documented tubal patency.

DESIGN

Cohort study.

SETTING

Outpatient clinics.

PATIENT(S)

In all, 1,250 infertile women with documented tubal patency enrolled in 1 of 2 randomized controlled trials: Pregnancy in Polycystic Ovary Syndrome II; and the Assessment of Multiple Intrauterine Gestations From Ovarian Stimulation.

INTERVENTION(S)

Sera were analyzed for anti-C. trachomatis immunoglobulin G (IgG)1 and IgG3 antibodies, using a research C. trachomatis EB ELISA. The optical density (OD)405 readings of ≥ 0.35 and ≥ 0.1 were considered positive for IgG1 and IgG3, respectively.

MAIN OUTCOME MEASURE(S)

Primary outcomes included pregnancy, live birth, and ectopic pregnancy. Log-linear regression was used to determine the relative risk after adjusting for age, race, treatment medication, smoking status, and current alcohol use.

RESULT(S)

A total of 243 (19%) women were seropositive for anti-C. trachomatis IgG3. They tended to be nonwhite and smokers. Anti-C. trachomatis IgG3 seropositive women were significantly less likely to conceive (risk ratio [RR] 0.65, 95% confidence interval [CI] 0.52-0.83) or to have a live birth (RR 0.59, 95% CI 0.43-0.80); these associations were weakened after adjusting for number of hysterosalpingography-documented patent tubes (RR 0.73, 95% CI 0.56-0.97) and (RR 0.73, 95% CI 0.50-1.04), respectively. Anti-C. trachomatis IgG3 seropositive women who conceived had a ×2.7 risk (95% CI 1.40-5.34) of ectopic pregnancy.

CONCLUSION(S)

Even in the presence of tubal patency, anti-C. trachomatis IgG3 seropositivity is associated with a lower likelihood of pregnancy. Anti-C. trachomatis IgG3 seropositive women have as high as 3 times the risk of ectopic pregnancy.

CLINICAL TRIAL REGISTRATION NUMBER

PPCOSII: NCT00719186 and AMIGOS: NCT01044862.

Ectopic pregnancy secondary to in vitro fertilisation-embryo transfer: pathogenic mechanisms and management strategies

BACKGROUND

Ectopic pregnancy (EP) is the leading cause of maternal morbidity and mortality during the first trimester and the incidence increases dramatically with in vitro fertilisation and embryo transfer (IVF-ET). The co-existence of an EP with a viable intrauterine pregnancy (IUP) is known as heterotopic pregnancy (HP) affecting about 1% of patients during assisted conception. EP/HP can cause significant morbidity and occasional mortality and represent diagnostic and therapeutic challenges, particularly during fertility treatment. Many risk factors related to IVF-ET techniques and the cause of infertility have been documented. The combination of transvaginal ultrasound (TVS) and serum human chorionic gonadotrophin (hCG) is the most reliable diagnostic tool, with early diagnosis of EP/HP permitting conservative management. This review describes the risk factors, diagnostic modalities and treatment approaches of EP/HP during IVF-ET and also their impact on subsequent fertility treatment.

METHODS

The scientific literature was searched for studies investigating EP/HP during IVF-ET. Publications in English and within the past 6 years were mostly selected.

RESULTS

A history of tubal infertility, pelvic inflammatory disease and specific aspects of embryo transfer technique are the most significant risk factors for later EP. Early measurement of serum hCG and performance of TVS by an expert operator as early as gestational week 5 can identify cases of possible EP. These women should be closely monitored with repeated ultrasound and hCG measurement until a diagnosis is reached. Treatment must be customised to the clinical condition and future fertility requirements of the patient. In cases of HP, the viable IUP can be preserved in the majority of cases but requires early detection of HP. No apparent negative impact of the different treatment approaches for EP/HP on subsequent IVF-ET, except for risk of recurrence.

CONCLUSIONS

EP/HP are tragic events in a couple's reproductive life, and the earlier the diagnosis the better the prognosis. Due to the increase incidence following IVF-ET, there is a compelling need to develop a diagnostic biomarker/algorithm that can predict pregnancy outcome with high sensitivity and specificity before IVF-ET to prevent and/or properly manage those who are at higher risk of EP/HP.

Antichlamydial antibodies, human fertility, and pregnancy wastage

Genital infections with Chlamydia trachomatis (C. trachomatis) continue to be a worldwide epidemic. Immune response to chlamydia is important to both clearance of the disease and disease pathogenesis. Interindividual responses and current chlamydial control programs will have enormous effects on this disease and its control strategies. Humoral immune response to C. trachomatis occurs in humans and persistent antibody levels appear to be most directly correlated with more severe and longstanding disease and with reinfection. There is a close correlation between the presence of antichlamydial antibodies in females and tubal factor infertility; the closest associations have been found for antibodies against chlamydial heat shock proteins. The latter antibodies have also been shown to be useful among infertile patients with prior ectopic pregnancy, and their presence has been correlated with poor IVF outcomes, including early pregnancy loss. We review the existing literature on chlamydial antibody testing in infertile patients and present an algorithm for such testing in the infertile couple.

Genome-wide identification of Chlamydia trachomatis antigens associated with tubal factor infertility

OBJECTIVE

To identify Chlamydia trachomatis antigens that can be used to differentially diagnose tubal factor infertility in comparison with previously reported heat shock protein 60.

DESIGN

In vitro study.

SETTING

Academic medical center.

PATIENT(S)

Infertile women with and without tubal pathology diagnosed laparoscopically.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Antibody responses to C. trachomatis in infertile women with or without tubal pathologies using a C. trachomatis genome-wide proteome array.

RESULT(S)

Comparison of the antibody profiles revealed 30 C. trachomatis antigens that were preferentially recognized in women with tubal factor infertility, with a detection sensitivity and specificity of 80.6% and 56.5%, respectively, 10 of which showed 100% specificity. A combination of CT443 and CT381 antigens yielded the highest detection sensitivity (67.7%) while maintaining 100% specificity.

CONCLUSION(S)

These findings have demonstrated that antibodies to CT443 and CT381, when used in combination, have higher sensitivity and specificity in predicting tubal factor infertility than other indicators for tubal factor infertility, such as heat shock protein 60 antibodies (35.5%, 100%) or hysterosalpingogram (65%, 83%). Using a panel of C. trachomatis antigens to serologically diagnose tubal factor infertility can save the patients from undertaking expensive and invasive procedures for determining tubal pathology and choosing treatment plans.