Chlamydial serologic studies and recurrent spontaneous abortion

The role of immunotherapy in in vitro fertilization and recurrent pregnancy loss: a systematic review and meta-analysis

OBJECTIVE

To study the current evidence on the role of immunotherapy in IVF and in the management of recurrent pregnancy loss (RPL).

DESIGN

Systematic review and meta-analysis.

SETTING

A literature search was performed using MEDLINE, PUBMED, CINAHL, and EMBASE until May 2017. Only randomized controlled trials were included, and a meta-analysis was carried out where appropriate.

PATIENT(S)

Women undergoing IVF treatment with or without a history of recurrent implantation failure and women with idiopathic RPL.

INTERVENTION(S)

Assessment of the efficacy of commonly used immunomodulators such as IV use of [1] immunoglobulin, [2] lymphocyte immunotherapy and [3] intralipid; intrauterine infusion of [4] granulocyte colony-stimulating factor and [5] peripheral blood mononuclear cells; subcutaneous administration of [6] TNF-alpha inhibitors, [7] leukaemia inhibitory factor; and oral administration of [8] glucocorticoids.

MAIN OUTCOME MEASURE(S)

The primary outcomes were live birth rate and miscarriage rate; secondary outcome was clinical pregnancy rate.

RESULT(S)

Of the 7,226 publications identified, 53 were selected during the initial screening; 30 satisfied the selection criteria and were included in this review.

CONCLUSION(S)

The available medical literature shows controversial results about the role of immunotherapy when used for improving reproductive outcomes. This study did not show a role for immunotherapy in improving the live birth rate in women undergoing IVF treatment or in the prevention of idiopathic RPL. Currently, immunotherapy should be used in the context of research and should not be used in routine clinical practice to improve reproductive outcomes.

Molecular Evidence of Chlamydia trachomatis Infection and Its Relation to Miscarriage

Background

Chlamydia trachomatis (CT) infection is the most common sexually transmitted disease in the world that can persist and also ascend in the genital tract. This intracellular and silent infection is related to some adverse pregnancy outcomes, such as miscarriage. The aims of this study were to explore the best CT screening tests using blood and vaginal samples and to investigate the correlation between CT infection and the incidence of miscarriage.

Materials and Methods

This case-control study was done in October 2013 through June 2014, using purposive sampling from 157 female participants with or without a history of miscarriage. The samples were taken after each participant had signed a letter of consent and had completed a questionnaire. To achieve the objectives of this study, polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) tests were performed on vaginal swabs and blood samples, respectively.

Results

PCR results showed a significantly higher CT infection rate in the miscarriage group compared to the control group (11.3 vs. 0%, P=0.007). Anti-CT IgG and IgA antibodies were found in 4.2 and 2.1% of cases in the miscarriage group, and in 1.7 and 6.7% of cases in the control group, respectively (P>0.05). Despite lower humoral responses in this study, positive samples were detected only by one of the following techniques; PCR, ELISA IgA and ELISA IgG. It also should be noted that PCR worked best in terms of detection.

Conclusion

Based on the obtained data, there is a strong association between molecular evidence of CT infection and miscarriage. A higher rate of CT detection in molecular tests compared to serological assays suggests that PCR could be used as the first-choice assay for detection of C. trachomatis. However, the importance of serological tests in detecting potential past CT infection or upper genital infection not amenable to sampling is undeniable.

Maternal exposure to sexually transmitted infections and schizophrenia among offspring

Animal models and epidemiologic studies suggest that prenatal maternal infection, and sexually transmitted infection (STI) in particular, is associated with an increased risk of schizophrenia in the offspring. However, findings from prior research studies on common infections, including herpes simplex virus type 2 (HSV-2) and Chlamydia trachomatis (C. trachomatis) have been inconsistent. To investigate these associations, we conducted a case-control study nested in the population-based Finnish Prenatal Study of Schizophrenia. Using linked national registries, 963 cases with schizophrenia (ICD-10 F20) or schizoaffective disorder (ICD-10 F25), and 963 matched controls were identified from among all persons born between 1983 and 1998 in Finland. HSV-2 IgG antibody levels were quantified in archived maternal serum samples drawn during pregnancy. Mothers of 16.4% of cases versus 12.6% of controls were HSV-2 seropositive. Mean levels of maternal HSV-2 IgG were marginally higher among cases than controls (index values of 0.98 versus 0.86; p=0.06). The unadjusted odds ratio (OR) of maternal HSV-2 IgG seropositivity was 1.33 (95% confidence interval (CI)=1.03-1.72, p=0.03). Following adjustment for covariates, the relationship was attenuated (OR=1.22, CI=0.93-1.60; p=0.14). In an exploratory analysis of another STI, C. trachomatis antibodies were measured in a subsample of 207 case-control pairs drawn from the cohort. The proportions of subjects that were seropositive and the mean levels of C. trachomatis antibodies were similar for cases and controls. This study does not support a strong association of HSV-2 or C. trachomatis IgG antibodies in maternal serum during early to mid-gestation with the development of schizophrenia in the offspring.

Role of Chlamydia trachomatis in miscarriage

To determine the role of Chlamydia trachomatis in miscarriage, we prospectively collected serum, cervicovaginal swab specimens, and placental samples from 386 women with and without miscarriage. Prevalence of immunoglobulin G against C. trachomatis was higher in the miscarriage group than in the control group (15.2% vs. 7.3%; p = 0.018). Association between C. trachomatis-positive serologic results and miscarriage remained significant after adjustment for age, origin, education, and number of sex partners (odds ratio 2.3, 95% confidence interval 1.1-4.9). C. trachomatis DNA was more frequently amplified from products of conception or placenta from women who had a miscarriage (4%) than from controls (0.7%; p = 0.026). Immunohistochemical analysis confirmed C. trachomatis in placenta from 5 of 7 patients with positive PCR results, whereas results of immunohistochemical analysis were negative in placenta samples from all 8 negative controls tested. Associations between miscarriage and serologic/molecular evidence of C. trachomatis infection support its role in miscarriage.

The influence of Chlamydia trachomatis infection on spontaneous abortions

PURPOSE

The aim of the study was to evaluate the frequency of Chlamydia trachomatis (C.t.) infection among women who experienced a miscarriage.

MATERIALS AND METHODS

Patients referred to the Centre for STD Research and Diagnostics in Bialystok from the Department of Perinatology and from gynaecological outpatient clinics, after spontaneous abortion were enrolled in the study. C.t. infection diagnostics were performed among 76 women with 1 miscarriage and 44 patients with > or =2 miscarriages in anamnesis. Forty-six patients in the 2nd and the 3rd trimester of normal pregnancy served as a comparative group. Endocervical swabs as well as blood serum were obtained. To detect chlamydial DNA, direct PCR method was performed (Roche, Molecular Systems, N.J., USA). To detect IgA and IgG specific anti-chlamydial antibodies we used immunoenzymatic assay (medac, Hamburg, Germany).

RESULTS

In patients with 1 miscarriage (gr.1), C.t. infection by means of PCR was detected in 11.8% of women (p=0.029), in patients with > or =2 miscarriages (gr.2) in 9.1% (p=0.198) and in the comparative group (gr.0) in 2.2%. Specific anti-chlamydial antibodies IgA class were detected in: 7.9 (p=0.082) in group 1, 4.5% (p=0.236) in group 2 and in 0% in group 0, and IgG class in 21.1% (p=0.024), 36.4% (p=0.000) and in 4.4%, respectively.

CONCLUSIONS

1. C.t. infection is an important causative agent of miscarriages in women. 2. C.t. infection diagnostic procedures should be considered in screening tests during pregnancy.

Causes of Fetal Wastage

Fetal wastage has many causes, but genetic factors are by far the most common. The earlier the pregnancy loss occurs, the greater the likelihood of genetic causation. Among first trimester abortions, 50% to 80% show chromosomal abnormalities, usually aneuploidy. This is greater than all other causes combined. Chromosomal numerical abnormalities can be recurrent and sporadic; failure to take this into account is a major pitfall in many reports addressing causation. Moreover, many causes of fetal wastage that are traditionally considered to be "nongenetic" are actually the result of perturbations of gene products-proteins. Among nongenetic causes of first trimester fetal wastage, the best established are thyroid abnormities; antifetal antibodies; and the inherited and acquired thrombophilias. The latter are more established in the second trimester. Uterine anomalies can lead to second trimester losses. Infections seem uncommon, and alloimmune causes are not validated.

Pregnancy Outcome in Recurrent Aborters is Not Influenced by Chlamydia IgA and/or G

PROBLEM

It is unclear whether chlamydia infection influences the miscarriage rate and immunological factors in patients with recurrent miscarriage.

METHOD OF STUDY

Chlamydia DNA, IgA and IgG to Chlamydia trachomatis, natural killer cell activity, complement 3 (C3), C4, hemolytic complement, antinuclear antibodies, antiphospholipid antibodies, prolactin, activated partial thromboplastin time, prothrombin time and fibrinogen were examined in 504 patients with a history of two or more consecutive first-trimester miscarriages. Subsequent pregnancy outcomes were compared between cases with and without antibodies to C. trachomatis.

RESULTS

Totals of 10 of 30 and 48 of 201 patients receiving no medication miscarried subsequently with and without chlamydia infection. Chlamydia IgA and/or IgG were associated with a high level of C3 but not other immunological and coagulatory parameters.

CONCLUSION

Antibodies to C. trachomatis do not influence subsequent pregnancy outcome in patients with a history of recurrent miscarriage.

Influence of infection with Chlamydia trachomatis on pregnancy outcome, infant health and life-long sequelae in infected offspring

This chapter deals with genital chlamydial infections in pregnancy and postpartum. There is increasing evidence that Chlamydia trachomatis infection may result in a number of adverse pregnancy outcomes, including early and late abortion, intrauterine infections of the fetus, stillbirth, prematurity, premature rupture of the membranes (PROM) and postpartum endometritis. Ectopic pregnancy is commonly associated with a previous tubal chlamydial infection where immunological reactions seem to play a role. C. trachomatis infection may be acquired as an intrauterine infection, as well as during transit through the birth channel, and this may result in neonatal conjunctivitis and/or pneumonia. The role of chlamydial infection in the sudden death syndrome has also been considered, but evidence so far is minimal. Neonatal chlamydial infection may cause life-long sequelae, such as obstructive lung disease. Genital chlamydial infections have been associated with problems in insemination and attempts at in vitro fertilization. The chapter also deals with screening of pregnant women for C. trachomatis and the treatment of infected mothers and their offspring.

First-trimester pregnancy loss and active Chlamydia trachomatis infection: correlation and ultrastructural evidence

The incidence of Chlamydia trachomatis (Ct) infection and the possible correlation between couples presenting with first-trimester spontaneous abortions and active Ct infection was assessed. Additionally, the ability of Ct to infect zona-free hamster oocytes was explored by incubating the oocytes with spermatozoa from infected patients. A total of 961 women and 750 men consulting our reproductive medicine centre were screened for Ct using direct immunofluorescence. The general incidence of Ct infection was 9.4% in females (90 of 961) and 13.9% in males (104 of 750). In women with spontaneous abortions the incidence of Ct was 21.0% (14 of 66) compared with 8.9% (23 of 59) for women without spontaneous abortions and term pregnancies (chi-square, P < 0.05). When both partners of the couples were considered (one or both partners infected), the incidence rose to 68.8% (22 of 32) (chi-square, P < 0.001). In vitro studies using electron microscopy demonstrated the presence of Ct on the surface of and inside the oocyte. These results indicate a correlation between an active Ct infection and spontaneous abortion. Electron microscopy studies suggested the possibility of direct oocyte infection by Ct. Two models are proposed for the pathogenesis of Ct-related early abortions: (i) direct zygote infection, and (ii) immune response to heat shock proteins expressed by the zygote and triggered by previous Ct infections.

Update on Chlamydia trachomatis

Chlamydia trachomatis is one the most important sexually transmitted diseases; it can cause serious sequelae despite the absence of symptoms in some people. It's estimated that about 25% of women who have acute salpingitis become infertile, and chlamydial infection is the commonest cause. The introduction of screening programs for its detection are still a topic of discussion. The literature shows that the total cost of examination and treatment of complications known to be associated with genital chlamydial infection (PID, chronic pelvic pain, tubal factor infertility) is generally higher than the total cost of a large-scale Chlamydia screening program. The selection of a diagnostic test for detection of chlamydial genital infection depends on availability, local expertise, and prevalence of Chlamydia trachomatis in the test population. Cell culture is too expensive in nonendemic regions, so the use of non-culture techniques is very attractive. PCR (polymerase chain reaction) and LCR (ligase chain reaction) are actually the two most commonly used alternatives to conventional methods for detecting STD agents. In fact, PCR and LCR have proved useful for detection of Chlamydia trachomatis in cervical and urethral samples both in symptomatic and asymptomatic women. Recently, testing of first-void urine (FVU) specimens with these techniques has shown that the amplification tests are as sensitive as tests with endocervical swab cultures.

Lack of association between serum antibodies to Chlamydia trachomatis and a history of recurrent pregnancy loss

OBJECTIVE

To study the relation between recurrent pregnancy loss (RPL) and infection with Chlamydia trachomatis, and to compare the prevalence of antibodies to C. trachomatis in women with primary and secondary RPL.

DESIGN

Prospective comparative study.

SETTING

University hospital and university student health center.

PATIENT(S)

Seventy patients with RPL were selected from women attending an RPL outpatient clinic; 40 normal parous women and 94 asymptomatic sexually active women served as controls.

INTERVENTION(S)

Blood samples were collected during the clinical examinations for RPL.

MAIN OUTCOME MEASURE(S)

Serum immunoglobulin (Ig) G and IgA antibodies were detected by two independent methods, a recombinant ELISA specific to the genus Chlamydia and microimmunofluorescence testing specific to the species C. trachomatis.

RESULT(S)

There was no statistically significant difference in the frequencies of IgG or IgA between the women with RPL and the controls. The antibody frequencies were similar in the women with primary and secondary RPL.

CONCLUSION(S)

The presence of serum antibodies to C. trachomatis is not associated with RPL. Women with primary and secondary RPL do not differ with respect to the prevalence of antichlamydial antibodies. Thus, women with RPL do not benefit from screening for chlamydial IgG or IgA antibodies.

A murine model for the study of Chlamydia trachomatis genital infections during pregnancy

Pregnant BALB/c mice were inoculated intravaginally on day 5 of gestation with the Chlamydia trachomatis mouse pneumonitis biovar. Animals that received 10(5), 10(6), or 10(7) inclusion-forming units (IFU) of C. trachomatis delivered prematurely on days 15 to 16 of gestation. A focal inflammatory infiltrate was observed in the wall of the uterus on the day 14 of gestation in animals inoculated with 10(5) IFU. In this group of mice, immunohistochemical analysis showed chlamydial inclusions in the endometrium and fetal membranes.

Serological survey of chlamydial antibody in post-natal sera

Questionnaires (3426; 72.8%) and blood samples (3890; 82.6%) were analysed from 4704 women post-natally. The answers to the questionnaire confirmed that those patients living in areas with the highest percentage employed in agriculture were most likely to be in direct or indirect contact with sheep or sheep products. When the 788 (20.3%) of the sera with group specific antibody were examined for type-specific antibody, 291 (7.5%) reacted with Chlamydia trachomatis, 153 (3.9%) with Chlamydia pneumoniae, but only one (0.03%) with Chlamydia psittaci. Thus, it would appear that C. psittaci was not an important pathogen in this survey, despite the largest proportion of blood samples being submitted from those most likely to be employed in agriculture. However, in the course of this survey the three patients who had previously suffered chlamydia-associated abortion had successful pregnancies and submitted blood specimens. Serological studies on the serial bloods from these patients showed that, despite developing antibody to the C. psittaci pool and the ovine abortion strain of C. psittaci following abortion, this antibody waned. At the time of the subsequent successful pregnancy, serological results would not have detected a previous C. psittaci infection, but one due to C. pneumoniae. Thus, the results of a survey such as this must be interpreted with caution.

Prevalence of Chlamydia trachomatis infection in a low-risk population in Hungary

BACKGROUND AND OBJECTIVE

Chlamydia trachomatis is the leading cause of nongonococcal urethritis and cervicitis in women. Because of the recent increases in the numbers of new cases and severe consequences, there is an urgent demand for the introduction of sensitive and specific rapid diagnostic methods.

GOAL

A multicenter examination involving seven centers was sponsored by the Hungarian Ministry of Health and Welfare in order to provide a survey of Chlamydia trachomatis in the gravid population. 6,161 women were tested between 1994 to 1995.

STUDY DESIGN

The seven centers were selected with regard to different aspects, from developed and less developed areas in the capital, two large provincial towns, and various other provincial regions reflecting either an industrial or an agricultural background. The nucleic acid hybridization method (PACE 2 Gen-Probe, San Diego, CA) was introduced in this low-risk population for the examination of Chlamydia trachomatis. In one center, a further two methods, antigen detection by ELISA (SYVA, CA) and cultivation on the McCoy cell line (staining with SYVA FITC-labeled antichlamydia monoclonal antibody), were applied.

RESULTS

International surveys and experience indicate that the proportion of the population threatened by Chlamydia trachomatis is above 10%. The overall average incidence of Chlamydia trachomatis cases in this low-risk gravid population was 5.74%. The data from the different centers ranged between 1.6% and 9.7%. The chlamydia-infected Hungarian gravid population is below the critical 10%, but there is one Hungarian county where the value is close to 10%.

CONCLUSIONS

In this provincial, industrial area, the number of unmarried and divorced gravida in a low economic situation is disproportionately high. For this disadvantaged population, permanent Chlamydia trachomatis screening was suggested. In the other centers, screening of pregnant women for Chlamydia trachomatis and the treatment of positive cases and their partners were suggested for pathological gravida with preterm labor and preterm rupture of the membranes.

Chlamydial antibodies in women who suffer miscarriage

OBJECTIVE

To ascertain the relation between previous chlamydial infection and miscarriage.

DESIGN

A prospective study of 349 women who had a miscarriage.

PARTICIPANTS

Women surgically treated for spontaneous pregnancy loss on an outpatient basis at a hospital.

SUBJECTS

Three hundred and forty-nine women who miscarried, of whom 91 had at least one previous miscarriage and 33 had had two or more miscarriages previously. Age-matched women who had a normal pregnancy served as controls.

INTERVENTIONS

Blood samples were drawn from patients and controls for antibody determination.

MAIN OUTCOME MEASURES

Patients and controls were compared regarding the frequency of Chlamydia trachomatis IgG antibodies (titre > or = 1/32). Antibodies to C. pneumoniae were also analysed to study cross reactivity.

RESULTS

The frequency of IgG antibodies among the patients was 137/349 (39.3%) which was not statistically different from that among controls (116/349; 33.2%). Even among those who had miscarried previously the antibody frequencies did not differ significantly between patients and controls. The rate of C. trachomatis antibodies was about the same whether or not antibodies to C. pneumoniae were present in both patients and controls.

CONCLUSION

No association was found serologically between previous chlamydial infection and miscarriage and no significant cross reactivity between C. pneumoniae and C. trachomatis could be detected.

Does serologic evidence of remote Chlamydia trachomatis infection and its heat shock protein (CHSP 60) affect in vitro fertilization-embryo transfer outcome?

OBJECTIVE

To examine IVF-ET outcome in patients with and without serologic evidence of Chlamydia trachomatis infection and chlamydia heat shock protein 60 (CHSP 60) antibodies.

DESIGN

Retrospective case control.

SETTING

University-affiliated IVF-ET program.

MAIN OUTCOME MEASURES

A total of 195 IVF-ET patients with tubal factor infertility underwent oocyte pick-up, 166 of these women had ET resulting in a total of 37 pregnancies. Serum antibody testing for evidence of remote C. trachomatis and CHSP 60, as well as pregnancy outcome, were determined for all patients.

RESULTS

There were no differences in pregnancy rates or outcomes between C. trachomatis seropositive versus seronegative groups: 27/118 (23%) C. trachomatis seropositive versus 10/77 (13%) C. trachomatis seronegative patients achieved pregnancy per oocyte pick-up. Pregnancy rates per ET were 27/105 (26%) in C. trachomatis seropositive versus 10/61 (16%) C. trachomatis seronegative patients. In the C. trachomatis positive subgroup, significantly higher pregnancy rates were found in the CHSP 60 antibody positive patients: 24/67 (36%) CHSP 60 positive versus 3/51 (6.0%) CHSP 60 negative patients were pregnant after oocyte pick-up (OR = 8.9, 95% CI = 2.3 to 27.5). Pregnancy rates per ET were 24/57 (42%) in CHSP 60 positive versus 3/48 (7%) CHSP 60 negative patients (OR = 10.9, 95% CI = 2.8 to 33.6). There were no significant differences in any group when examining the following pregnancy outcomes: spontaneous abortion, ectopic pregnancy, preterm and multiple pregnancy rates.

CONCLUSIONS

[1] There are no differences in pregnancy rates or outcomes in patients with and without serologic evidence of previous C. trachomatis infections. [2] In women seropositive for C. trachomatis, significantly higher pregnancy rates are found in women who are CHSP 60 antibody positive versus negative. [3] Pregnancy outcomes do not appear to be different between these groups.