Immunological Modes of Pregnancy Loss

Immunological Risk Factors in Recurrent Pregnancy Loss in Patients With Hereditary Thrombophilia

BACKGROUND

Recurrent pregnancy loss (RPL) is a complicated reproductive disorder with underlying genetic and immunological causes. RPL may be influenced by hereditary thrombophilia, a class of blood clotting-related genetic abnormalities, via the vascular and immune systems. This study examines the immunological characteristics that hereditary thrombophilia patients have in common with RPL.

METHODS

A prospective cohort study included 300 patients split into two groups: a control group without hereditary thrombophilia and a group with the condition. Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) levels were measured, along with demographic specifics, antiphospholipid antibodies, natural killer (NK) cell counts, and other cytokines. Group differences were found using statistical analysis.

RESULTS

Antiphospholipid antibodies were significantly more common in the thrombophilia group (42% testing positive, p=0.001) compared to the control group (12% testing positive), despite demographic factors being similar between groups (p=0.372 and p=0.093). When body mass index (BMI) was taken into account, the study found a statistically significant difference (p=0.046), with the thrombophilia group having a higher mean BMI (26.3 kg/m2, standard deviation (SD): 2.8) than the control group (24.7 kg/m2, SD: 3.1). IL-6 (14.8 pg/mL, SD: 3.2, p=0.029) were higher than the control group (12.4 pg/mL, SD: 2.1), and TNF-α levels were higher in the thrombophilia group (10.5 pg/mL, SD: 2.0, p=0.012) compared to the control group (8.9 pg/mL, SD: 1.5), but NK cell counts did not differ significantly (p=0.213).

CONCLUSION

This study emphasizes the role of elevated pro-inflammatory cytokines (IL-6 and TNF-α) and antiphospholipid antibodies in RPL among people with hereditary thrombophilia. In this population, early detection and immunomodulatory interventions may improve pregnancy outcomes. To fully comprehend these mechanisms and create customized treatments, collaborative research is required.

lncRNA CLRN1-AS1 reduces adhesion ability of human trophoblasts via CXCL10/CXCL11

INTRODUCTION

Trophoblast cells play an important role in embryo recognition and localization, as well as placental development during embryo implantation. Dysfunction of trophoblastic cells causes pathological changes that lead to insufficient recognition, positioning, and adhesion during embryo implantation, ultimately leading to embryo development has stopped.

METHODS

High-throughput sequencing was used to identify differentially expressed the mRNA and lncRNA in the villi tissue of pregnant women diagnosed with embryo cessation. In vitro implantation cell models, characteristic analysis, and bio information analysis confirmed that CLRN1-AS1 affected the adhesion function of trophoblast cells by influencing the chemokines CXCL10/CXCL11.

RESULTS

High throughput sequencing technology was used to identify 438 differentially expressed mRNAs and 41 lncRNAs. The three lncRNAs, namely CLRN1-AS1, USP27X-AS1, and AC104809.4, were screened by the mRNA-lncRNA network. In vitro implantation model suggested that all three lncRNAs could affect the adhesion between trophoblast cells, among which CLRN1-AS1 had the most significant effect. Characteristic analysis and correlation analysis showed that CLRN1-AS1 was closely related to the expression of six adhesion-related genes, LAMA1, FGL2, ITGB2, FBN1, EMP2, and PODN. Cell experiments and re-sequencing confirmed that CLRN1-AS1 could affect the adhesion ability of trophoblast cells to the extracellular matrix, and its process was related to the chemokine CXCL10/CXCL11.

DISCUSSION

These results constructed the network of mRNA-lncRNA and enrichment when embryonic development has stopped and found CLRN1-AS1 highly correlated to failure of embryo implantation, and revealed that CLRN1-AS1 modulates the adhesion ability of trophoblast cells to the extracellular matrix via the chemokines CXCL10/CXCL11 during the early stage of embryo implantation.

Placental Therapeutic Targets and Nanodelivery Systems

Pregnancy complications affect millions of women each year. Some of these diseases have high morbidity and mortality such as preeclampsia. At present, there is no safe and effective treatment for pregnancy complications, so it is still a difficult clinical problem. As many pregnancy complications are closely related to placental dysplasia, placenta-specific therapy, as an important method, is expected to be a safe, effective, and specific therapeutic strategy. This review explains in detail the placenta physiological structure, characteristics, and action mechanism of some biomolecules and signaling pathways that play roles in normal development and disorders of the development of the placenta, and how to use these biomolecules as therapeutic targets when the placenta disorder causes disease, combining the latest progress in the field of nanodelivery systems, so as to lay a foundation for the development of placenta-specific therapy of pregnancy complications.

Neutrophil-to-lymphocyte ratio is a predictor of biochemical miscarriage following artificial frozen embryo transfer cycles

The aim of this study is to examine the relationship between complete blood count (CBC) inflammatory markers and pregnancy outcome following artificial frozen embryo transfer cycles (AC-FET). This was a retrospective cohort study including 183 patients undergoing an AC-FET. The inflammatory markers including white blood cell count (WCC), neutrophil and lymphocyte count, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were compared between cycles with and without clinical pregnancies. Furthermore, these markers were compared between pregnancies with and without biochemical and clinical miscarriages. NLR was significantly higher in cycles with biochemical miscarriages (p = 0.009). Receiver operating curve analysis was performed to assess the role of NLR in predicting biochemical pregnancy. The area under the curve was 0.714 (95% confidence interval; 0.578-0.850, p = 0.009). The optimal cut-off value for NLR that was associated with biochemical miscarriage was 2.48 with 63% sensitivity and 75% specificity. A logistic regression analysis was performed with biochemical miscarriage as the dependent variable. An NLR value below 2.48 was an independent variable to affect biochemical miscarriage (OR: 0.2, 95% CI 0.05-0.92, p = 0.030). NLR emerged as a reliable predictor of biochemical miscarriage in AC-FET.Impact StatementWhat is already known on this subject? NLR and PLR are novel markers of inflammation. They are related to various gynecological and obstetric conditions including spontaneous abortion, preeclampsia. These markers are also associated with assisted reproductive technology success in fresh cycles.What the results of this study add? This is the first study to investigate the association of these markers with FET cycles. Our results have shown that cycles that ended in biochemical miscarriage had a significantly higher NLR compared with cycles continuing as a clinical pregnancy. An NLR value above 2.48 was predictive of biochemical miscarriage following AC-FET.What the implications are of these findings for clinical practice and/or further research? A high NLR level might have a significant value for the identification of patients at risk of biochemical miscarriage. Future research should assess the impact of anti-inflammatory agents on pregnancy outcomes in patient populations where systemic inflammation is documented by CBC inflammatory markers.

Temporal changes in cyclinD-CDK4/CDK6 and cyclinE-CDK2 pathways: implications for the mechanism of deficient decidualization in an immune-based mouse model of unexplained recurrent spontaneous abortion

BACKGROUND

Deficient endometrial decidualization has been associated with URSA. However, the underlying mechanism is poorly understood. This study aimed to investigate the temporal cytokine changes and the involvement of CyclinD-CDK4/6 and CyclinE-CDK2 pathways in the regulation of the G1 phase of the cell cycle during decidualization in a murine model of URSA.

METHODS

Serum and decidual tissues of mice were collected from GD4 to GD8. The embryo resorption and abortion rates were observed on GD8 and the decidual tissue status was assessed. In addition, PRL, Cyclin D, CDK6, CDK4, Cyclin E, CDK2 expression in mice were measured.

RESULTS

URSA mice showed high embryo resorption rate and PRL, Cyclin D, Cyclin E CDK2, CDK4, CDK6 down-regulation during decidualization. The hyperactivated Cyclin D-CDK4/CDK6 and cyclin E/CDK2 pathways inhibit the decidualization process and leading to deficient decidualization.

CONCLUSION

Insufficient decidualization is an important mechanism of URSA. which is related to the decrease of Cyclin D、Cyclin E、 CDK2、CDK4 and CDK6 in decidualization process of URSA.

Deoxynivalenol exposure during pregnancy has adverse effects on placental structure and immunity in mice model

Deoxynivalenol (DON), a highly prevalent food contaminant, is known to induce reproductive and immunotoxicity in humans upon exposure. The present study focused on the consequences of exposure to DON during pregnancy for placental barrier and immune function, as well as fetal survival. Female mice received diets contaminated with DON (6.25 and 12.5 mg/kg of diet), starting immediately after mating until the end of the experiment. On day 17 of pregnancy the animals were killed, and maternal and fetal samples were collected for further analysis. Feeding on DON-contaminated diets decreased fetal survival, and DON was detected at significant levels in the fetus. Placentae from DON-exposed mice revealed a reduction in expression of junctional proteins, ZO-1, E-cadherin and claudins, upregulation of AHR mRNA expressions, and increase in IFN-ꝩ, IL-6 and IL-4 production. In conclusion, results of this study demonstrate harmful effects of DON on the course of pregnancy and fetal survival, which might be due to immunological changes in maternal immune organs and placenta. Altogether, these data underline the importance of the quality of maternal diet during pregnancy as they clearly demonstrate the potential harmful effects of a commonly present food-contaminant.

Correlation of TNF-α, IFN-γ and TGF-β Expression with In-vitro Fertilization Success Rates in Women with Recurrent Implantation Failure Undergoing Treatment with Intra-lipid Infusion

This study aimed at assessing the correlations between gene expression of TNF-a, IFN-g, TGF-β in peripheral lymphocytes from women suffering from repeated implantation failure before and after intravenous Intra-lipid (IL) therapy, and correlation between changes in gene expression with IL infusion and success rate of IVF cycles. Twenty-three women complaining of unexplained infertility without history of autoimmune disorders, or immunodeficient diseases were included. All women included aged <40 years, BMI <28 with history of recurrent IVF cycles failure, seeking medical advice for new IVF trial. All were average responders to induction of ovulation (≥5 oocytes in each cycle) with good quality embryos transferred to uterus at proper time. Included women received 200 ml of 10% IL slowly intravenous. Two venous blood samples were taken from all candidates, one before IL infusion and the second was at day of embryo transfer. The current study detected a significant reduction of expression in TNF-a and increased expression of TGF-β, while non-significant reduction in expression of IFN-g after treatment. Significant associations between reduction of TNF-α, IFN-g expression and positive clinical and ongoing pregnancy were observed, while increased TGF-β expression was associated with only positive ongoing pregnancy. In conclusion, IL therapy might have a positive impact on IVF pregnancy rates via alterations in peripheral cytokines expression mainly reduction of TNF-a mRNA expression and increased TGF-b mRNA expression.

A combination of immune cell types identified through ensemble machine learning strategy detects altered profile in recurrent pregnancy loss: a pilot study

OBJECTIVE

To compare the immunologic profiles of peripheral and menstrual blood (MB) of women who experience recurrent pregnancy loss and women without pregnancy complications.

DESIGN

Explorative case-control study. Cross-sectional assessment of flow cytometry-derived immunologic profiles.

SETTING

Academic medical center.

PATIENT(S)

Women who experienced more than 2 consecutive miscarriages.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Flow cytometry-based immune profiles of uterine and systemic immunity (recurrent pregnancy loss, n = 18; control, n = 14) assessed by machine learning classifiers in an ensemble strategy, followed by recursive feature selection.

RESULT(S)

In peripheral blood, the combination of 4 cell types (nonswitched memory B cells, CD8+ T cells, CD56bright CD16- natural killer [NKbright] cells, and CD4+ effector T cells) classified samples correctly to their respective cohort. The identified classifying cell types in peripheral blood differed from the results observed in MB, where a combination of 6 cell types (Ki67+CD8+ T cells, (Human leukocyte antigen-DR+) regulatory T cells, CD27+ B cells, NKbright cells, regulatory T cells, and CD24HiCD38Hi B cells) plus age allowed for assigning samples correctly to their respective cohort. Based on the combination of these features, the average area under the curve of a receiver operating characteristic curve and the associated accuracy were >0.8 for both sample sources.

CONCLUSION(S)

A combination of immune subsets for cohort classification allows for robust identification of immune parameters with possible diagnostic value. The noninvasive source of MB holds several opportunities to assess and monitor reproductive health.

Antiphospholipid antibodies in women with recurrent embryo implantation failure: A systematic review and meta-analysis

OBJECTIVE

Antiphospholipid antibodies (aPL) are related to poor pregnancy outcomes, but their effect on embryo implantation is unclear. We aimed to assess the prevalence of different aPL in women with recurrent implantation failure (RIF).

METHODS

We searched studies in PubMed (MEDLINE), Scopus and Cochrane Library. Quality of studies was scored by the Newcastle-Ottawa Scale and risk of bias assessment by items described in RevMan5 software. Statistical analyses were made using random-effects model and presented as pooled Odds Ratio (OR), 95% confidence interval (CI). Heterogeneity was assessed by I²% and D²%.

RESULTS

This systematic review and meta-analysis included 17 studies and showed a high degree of variability in aPL positivity in RIF. In the latter, the risk of bias assessment suggested unclear bias on study performance with a median sample size and interquartile range for RIF patients and fertile women of 96 (57-417) and 100 (60.5-202.5), respectively. Among the criteria aPL, IgG anticardiolipin autoantibodies (OR 5.02, 95% CI [1.95, 12.93]) were associated with RIF. Within the non-criteria aPL, anti-β2 glycoprotein I-IgA (OR 64.8, 95% CI [9.74, 431.0]), and antiphosphatidylglycerol-IgG and IgM (OR 10.74, 95% CI [5.25, 22.0]; OR 4.26, 95% CI [1.76,10.31]; respectively) were associated with RIF, too.

CONCLUSIONS

Anticardiolipin-IgG is a prevalent autoantibody in women with RIF. Three other non-criteria aPL, aβ2GP I-IgA, aPG-IgG and aPG-IgM also present a positive rate in RIF. Overall, these results advise about testing them as indicators of RIF risk in women seeking IVF treatment.

A Review of Roles of Uterine Artery Doppler in Pregnancy Complications

The invasion of trophoblasts into the uterine decidua and decidual vessels is critical for the formation of placenta. The defects of placentation are related to the etiologies of preeclampsia (PE), fetal growth restriction (FGR), and small-for-gestational age (SGA) neonates. It is possible to predict significant vascular events during pregnancy through uterine artery Doppler (UAD). From the implantation stage to the end of pregnancy, detecting changes in uterine and placental blood vessels can provide a favorable diagnostic instrument for pregnancy complications. This review aims to collect literature about the roles of UAD in pregnancy complications. We consider all relevant articles in English from January 1, 1983 to October 30, 2021. Predicting pregnancy complications in advance allows practitioners to carry out timely interventions to avoid or lessen the harm to mothers and neonates. Administering low-dose aspirin daily before 16 weeks of pregnancy can significantly reduce the incidence of pregnancy complications. From early pregnancy to late pregnancy, UAD can combine with other maternal factors, biochemical indicators, and fetal measurement data to identify high-risk population. The identification of high-risk groups can also lessen maternal mortality. Besides, through moderate risk stratification, stringent monitoring for high-risk pregnant women can be implemented, decreasing the incidence of adversities.

circRNA-DURSA regulates trophoblast apoptosis via miR-760-HIST1H2BE axis in unexplained recurrent spontaneous abortion

Unexplained recurrent spontaneous abortion (URSA) is one of the most intractable clinical challenges in reproduction. As a specific type of endogenous non-coding RNA, circular RNAs (circRNAs) have great pre-clinical diagnostic and therapeutic values in diseases. Recently, thousands of circRNAs were detected in human pre-implantation embryos, indicating that circRNAs potentially have important regulatory functions. However, the roles of circRNAs in URSA remain largely unknown. In this study, we elucidated deregulated circRNA expression and distinct competing endogenous RNA (ceRNA) networks by comparing URSA placental villus with that of patients with normal pregnancy using microarrays. We characterized a distinct circRNA, circRNA-0050703, which is downregulated in URSA placental villus (thus we named it circRNA-DURSA). Silencing of circRNA-DURSA results in trophoblast cell apoptosis in vitro. Furthermore, mechanistic dissection revealed that circRNA-DURSA exerts its effects by competitively binding to miR-760, which post-transcriptionally targets HIST1H2BE. Additionally, after circRNA-DURSA silencing in vivo, the numbers of implanted embryos decreased significantly. These results reveal the regulatory roles of circRNA-DURSA in trophoblasts and identified a distinct circRNA-DURSA/miR-760/HIST1H2BE axis as potentially important diagnostic and therapeutic targets for URSA treatment.

Progesterone stimulates histone citrullination to increase IGFBP1 expression in uterine cells

Peptidylarginine deiminases (PAD) enzymes were initially characterized in uteri, but since then little research has examined their function in this tissue. PADs post-translationally convert arginine residues in target proteins to citrulline and are highly expressed in ovine caruncle epithelia and ovine uterine luminal epithelial (OLE)-derived cell line. Progesterone (P4) not only maintains the uterine epithelia but also regulates the expression of endometrial genes that code for proteins that comprise the histotroph and are critical during early pregnancy. Given this, we tested whether P4 stimulates PAD-catalyzed histone citrullination to epigenetically regulate expression of the histotroph gene insulin-like growth factor binding protein 1 (IGFBP1) in OLE cells. 100 nM P4 significantly increases IGFBP1 mRNA expression; however, this increase is attenuated by pre-treating OLE cells with 100 nM progesterone receptor antagonist RU486 or 2 µM of a pan-PAD inhibitor. P4 treatment of OLE cells also stimulates citrullination of histone H3 arginine residues 2, 8, and 17 leading to enrichment of the ovine IGFBP1 gene promoter. Since PAD2 nuclear translocation and catalytic activity require calcium, we next investigated whether P4 triggers calcium influx in OLE cells. OLE cells were pre-treated with 10 nM nicardipine, an L-type calcium channel blocker, followed by stimulation with P4. Using fura2-AM imaging, we found that P4 initiates a rapid calcium influx through L-type calcium channels in OLE cells. Furthermore, this influx is necessary for PAD2 nuclear translocation and resulting citrullination of histone H3 arginine residues 2, 8, and 17. Our work suggests that P4 stimulates rapid calcium influx through L-type calcium channels initiating PAD-catalyzed histone citrullination and an increase in IGFBP1 expression.

Clinical consequences of defective decidualization

Decidualization is characterized by a series of genetic, metabolic, morphological, biochemical, vascular and immune changes occurring in the endometrial stroma in response to the implanting embryo or even before conception and involves the stromal cells of the endometrium. It is a fundamental reproductive event occurring in mammalian species with hemochorial placentation. A growing body of experimental and clinical evidence strongly suggests that defective or disrupted decidualization contributes to the establishment of an inappropriate maternal-fetal interface. This has relevant clinical consequences, ranging from recurrent implantation failure and recurrent pregnancy loss in early pregnancy to several significant complications of advanced gestation. Moreover, recent evidence indicates that selected diseases of the endometrium, such as chronic endometritis and endometriosis, can have a detrimental impact on the decidualization response in the endometrium and may help explain some aspects of the reduced reproductive outcome associated with these conditions. Further research efforts are needed to fully understand the biomolecular mechanisms ans events underlying an abnormal decidualization response. This will permit the development of new diagnostic and therapeutic strategies aimed to improve the likelihood of achieveing a successful pregnancy.

Understanding the natural selection of human embryos: blastocyst quality modulates the inflammatory response during the peri-implantation period

PROBLEM

Decidualized cells display an active role during embryo implantation sensing blastocyst quality, allowing the implantation of normal developed blastocysts and preventing the invasion of impaired developed ones. Here, we characterized the immune microenvironment generated by decidualized cells in response to soluble factors secreted by blastocysts that shape the receptive milieu.

METHOD OF STUDY

We used an in vitro model of decidualization based on the Human Endometrial Stromal Cells line (HESC) differentiated with medroxiprogesterone and dibutyryl-cAMP, then treated with human blastocysts-conditioned media (BCM) classified according to their quality.

RESULTS

Decidualized cells treated with BCM from impaired developed blastocysts increased IL-1β production. Next, we evaluated the ability of decidualized cells to modulate other mediators associated with menstruation as chemokines. Decidualized cells responded to stimulation with BCM from impaired developed blastocysts increasing CXCL12 expression and CXCL8 secretion. The modulation of these markers was associated with the recruitment and activation of neutrophils, while regulatory T cells recruitment was restrained. These changes were not observed in the presence of BCM from normal developed blastocysts.

CONCLUSION

Soluble factors released by impaired developed blastocysts induce an exacerbated inflammatory response associated with neutrophils recruitment and activation, providing new clues to understand the molecular basis of the embryo-endometrial dialogue.

Relationship between common interleukin 1-beta gene polymorphisms and the risk of gestational disorders: An updated meta-analysis

Background: To quantitatively estimate the relationship between IL-1β -511C>T, -31T>C, and +3954C>T polymorphisms and risk of gestational disorders. Methods: In this meta-analysis, eligible publications were searched in Web of Knowledge, MEDLINE, PubMed, Scopus, and Google Scholar databases (updated April 2020), using appropriate or relevant keywords. Case-control population-based reports were included if provided with genotypic frequencies of both studied groups. Statistical analyses were performed using the MetaGenyo web tool software, where a P value less than 0.05 indicated a significant association. For the assessment of between-study variations, heterogeneity analysis was applied with the I² statistics. Results: A total of thirteen studies were included. We observed a significant association between IL-1β-31T>C polymorphism and reduced risk of gestational disorders under codominant CT vs. CC [OR= 0.74, CI (0.59-0.92)], and dominant CT+TT vs. CC [OR= 0.74, CI (0.60-0.91)] contrasted genetic models. The stratified analysis considering the disease type showed that the 511C>T variant, under the recessive CC vs. CT+TT model, enhanced the risk of preterm birth by 1.29 fold. Conclusion: Our results failed to support an association between two IL-1β polymorphisms, 511C>T and +3954C>T, with the overall risk of gestational disorders. In contrast, the 31T>C variant reduced the incidence of such diseases. Further studies are encouraged to get more precise estimates of effect sizes.

Interleukin-1 beta is significantly upregulated in the decidua of spontaneous and recurrent miscarriage placentas

BACKGROUND

Pregnancy is an extraordinarily complex immunological process. For successful pregnancy maintenance the maternal immune system must adapt to and tolerate the semi-allogenic fetus at the fetomaternal interface of the placenta. This balance is regulated by cytokines with a predominant T helper 2 (Th-2) system and a suppressed inflammatory T helper 1 (Th-1) response. This study investigates the role of the Th-1 pro-inflammatory cytokine Interleukin-1 beta (IL-1β) and its role in early pregnancy loss.

PATIENTS AND METHODS

In order to identify differences in IL- β levels a TaqMan® Human Cytokine Network Array, with placental tissue obtained from patients with healthy pregnancies (n = 15) and recurrent miscarriage (n = 15), was carried out. Protein expression of IL-1β in the decidua of healthy pregnancies (n = 15), spontaneous (n = 18) and recurrent miscarriages (n = 15), was investigated by immunohistochemistry. The identification of IL-1β expressing cells in the decidua was done with double-immunofluorescence.

RESULTS

Gene expression analysis identified a nearly 54-times higher expression of IL-1β in placental tissue of patients suffering from recurrent abortion. Immunohistochemistry confirmed a significant upregulation of IL-1β in the decidua of recurrent miscarriage specimens (p = 0.01) as well as in the decidua of women with spontaneous abortion (p = 0.001). Double-immunofluorescence identified decidual stoma cells as IL-1β expressing cells.

CONCLUSION

Significant upregulation of IL-1β may be associated with an imbalanced immune system and a procoagulant state that could be responsible for early pregnancy loss. These results provide new evidence of the complex interplay of IL-1β at the fetomaternal interface and its crucial role in miscarriage processes.

Daidzein supplementation enhances embryo survival by improving hormones, antioxidant capacity, and metabolic profiles of amniotic fluid in sows

Daidzein (DAI) is a kind of natural isoflavonic phytoestrogen with estrogenic activity. However, little is known about its influence on early fetal growth in mammalian animals. The current study aimed to explore the characteristics of amniotic fluid exposure to dietary DAI using ¹H NMR-based metabolomics and biochemical analysis. Here, we found that DAI supplementation at a dose of 200 mg kg^-1 significantly enhanced the number of viable embryos at the early gestation stage (P < 0.05). DAI significantly elevated the concentrations of estrogen (E) and insulin-like growth factor-I (IGF-I) in the amniotic fluid (P < 0.05). Moreover, DAI tended to increase the concentration of progesterone, but decrease the concentration of tumor necrosis factor α (TNF-α) in the amniotic fluid (0.05 < P < 0.10). Interestingly, the activity of glutathione peroxidase (GSH-Px) was higher in the DAI group than in the CON group (P < 0.05). An ¹H NMR-based metabolomics analysis identified and quantified more than 30 compounds in the amniotic fluid, and some critical metabolites such as arginine, creatine, and citrate were found to be significantly elevated upon DAI supplementation (P < 0.05). Importantly, the metabolic pathways involved in arginine and proline metabolisms were found to be significantly affected by DAI. Collectively, dietary DAI may improve embryo survival by improving hormones, antioxidant capacity, and metabolic profiles in the maternal amniotic fluid.

Endometrial uNK cell counts do not predict successful implantation in an IVF population

STUDY QUESTION

Are uterine natural killer (uNK) cell numbers and their distribution relative to endometrial arterioles altered in women with recurrent implantation failure (RIF) compared to women with embryo implantation success (IS)?

SUMMARY ANSWER

uNK cell numbers and their distribution relative to endometrial arterioles are not significantly different in women with RIF compared to women in whom embryo implantation occurs successfully following IVF.

WHAT IS ALREADY KNOWN

uNK cells are regulators of decidual angiogenesis and spiral arteriole remodelling during early pregnancy. Although some studies have shown that uNK cell numbers may be altered in women with RIF, the methods used to measure uNK cell numbers have proven inconsistent, making reproduction of these results difficult. It is unclear, therefore, whether the results reported so far are reproducible. Moreover, it is not known how uNK cell numbers may impact IVF outcomes. Despite the lack of conclusive evidence, uNK cell numbers are often evaluated as a prognostic criterion in women undergoing assisted reproductive procedures.

STUDY DESIGN, SIZE, DURATION

Endometrial pipelle biopsies were collected 6-8 days post-LH surge in natural cycles from women with RIF (n = 14), women with IS (n = 11) and women with potential RIF at the time of the study (PRIF; n = 9) from 2013 to 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

uNK cells (i.e. CD56+ and/or CD16+ phenotypes) and their distribution relative to endometrial arterioles were investigated by standard immunohistochemistry protocols and quantified using Aperio ScanScopeXT images digitized by ImageJ and deconvoluted into binary images for single cell quantification using a Gaussian Blur and Yen algorithm.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no significant difference in the cell density of CD56+ or CD16+ uNK cells in women with RIF compared to women with IS or PRIF. There was a higher proportion of uNK cells in the distal regions compared to the regions closest to the arterioles in all patient groups. Further, we identified a significant reduction in uNK cell density in women who had a previous pregnancy compared to those who had not, regardless of their current implantation status.

LARGE SCALE DATA

Not applicable.

LIMITATIONS, REASONS FOR CAUTION

Spiral arterioles could not always be accurately identified by digital image analysis; therefore, all endometrial arterioles were selected and analysed. Patient numbers for the study were low. However, as the clinical phenotypes of each patient were well defined, and endometrial dating was accurately determined by three independent pathologists, differences between patient groups with respect to the uNK numbers and distribution should have been measurable if uNK cell counts were to be useful as a prognostic marker of RIF.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings demonstrate that CD56+ and CD16+ uNK cell numbers are not significantly different in women with RIF in a typical cohort of women undergoing IVF. Further, prior pregnancy was associated with a significantly reduced number of uNK cells in both the RIF and IS patient groups, suggestive of a long-term pregnancy induced suppression of uNK cells. Combined, these findings do not support the clinical value of using uNK cell numbers as a prognostic indicator of implantation success with IVF treatment.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for this work was provided by Royal Women's Hospital Foundation. P.P. was supported by an NHMRC Early Career Fellowship [TF 11/14] and W.T.T. was supported by an NHMRC Postgraduate Scholarship [1055814]. The authors do not have any competing interests with this study.

Reduced frequency and functional defects of CD4+CD25highCD127low/- regulatory T cells in patients with unexplained recurrent spontaneous abortion

BACKGROUND

Unexplained recurrent spontaneous abortion (URSA) is defined as two or more consecutive pregnancy losses, generally of unknown cause; it is related to a failure of fetal-maternal immunological tolerance. Regulatory T cells (Tregs) exert immunosuppressive effects, which are essential to maintain fetal-maternal immunological tolerance and regulate immune balance. In this study, we used the specific cell-surface phenotype of CD4⁺CD25^highCD127^low/- Tregs to investigate the number and suppressive function of Tregs isolated from the peripheral blood of patients with URSA with the aim of expanding our understanding of their role in URSA.

METHODS

We isolated a relatively pure population of peripheral CD4⁺CD25^highCD127^low/- Tregs and CD4⁺CD25^- responder T cells (Tresps) from the patients with URSA and normal fertile nonpregnant control women via fluorescence-activated cell sorting. We compared the frequency, suppressive capacity, and forkhead box transcription factor P3 (FOXP3) expression of Tregs in the peripheral blood between patients with URSA and normal controls.

RESULTS

The frequency of CD4⁺CD25^highCD127^low/- Tregs in the peripheral blood was lower in URSA patients than in the controls (P < 0.05). The mean fluorescence intensity of FOXP3 and FOXP3 mRNA expression in Tregs was also significantly lower in the URSA patients (P < 0.01). Tregs suppressed the activity of autologous Tresps stimulated with anti-CD3/CD28 beads in a concentration-dependent manner, with the strongest suppression occurring in cocultures with a 1:1 Treg:Tresp ratio in both groups; however, patient-derived Tregs exhibited a poorer capacity to suppress the proliferation of autologous Tresps than the Tregs from normal controls (P < 0.01). Moreover, Tregs isolated from URSA patients inhibited the proliferation of Tresps from normal controls less potently than the Tregs from normal controls (P < 0.01), and Tresps from URSA patients were less effectively suppressed by autologous Tregs than by those from normal controls (P < 0.01). Tresp activity were intact in both groups.

CONCLUSIONS

We observed a lower frequency of peripheral CD4⁺CD25^highCD127^low/- Tregs with lower FOXP3 expression in the peripheral blood of URSA patients. In addition, highly purified Tregs from patients with URSA exhibited impaired suppressive effects. The defect in immune regulation in URSA patients appears to be primarily related to impaired Tregs, and not to increased resistance of Tresps to suppression. Our findings reveal a potential novel therapeutic target for URSA.

Evaluation of T cell cytokines and their role in recurrent miscarriage

Recurrent miscarriage (RM) is defined as two or more consecutive pregnancy losses that affect approximately 5% of conceived women worldwide. RM is a multi-factorial reproductive problem and has been associated with parental chromosomal abnormalities, embryonic chromosomal rearrangements, uterine anomalies, autoimmune disorders, endocrine dysfunction, thrombophilia, life style factors, and maternal infections. However, the exact cause is still undecided in remaining 50% of cases. Immunological rejection of the embryo due to exacerbated maternal immune reaction against paternal embryonic antigens has been set forth as one of the significant reason for RM. The accurate means that shield the embryo during normal pregnancy from the attack of maternal immune network and dismissal are inadequately implicit. However, it is suggested that the genetically irreconcilable embryo escapes maternal immune rejection due to communication among many vital cytokines exuded at maternal-embryonic interface both by maternal and embryonic cells. Previous investigations suggested the Th1/Th2 dominance in altered immunity of RM patients, according to which the allogenic embryo flees maternal T cell reaction by inclining the Th0 differentiation toward Th2 pathway resulting into diminished pro-inflammatory Th1 immunity. However, recently pro-inflammatory Th17 cells and immunoregulatory Treg cells have been discovered as essential immune players in RM besides Th1/Th2 components. Cytokines are believed to develop a complicated regulatory network so as to establish a state of homeostasis between the semi-allogenic embryo and the maternal immune system. However, an adverse imbalance among cytokines at maternal-embryonic interface perhaps due to their gene polymorphisms may render immunoregulatory means not enough to re-establish homeostasis and thus may collapse pregnancy.

Uterine Dendritic Cells Modulation by Mesenchymal Stem Cells Provides A Protective Microenvironment at The Feto-Maternal Interface: Improved Pregnancy Outcome in Abortion-Prone Mice

Objective

Dendritic cells (DCs) as major regulators of the immune response in the decidua play a pivotal role in establishment and maintenance of pregnancy. Immunological disorders are considered to be the main causes of unexplained recurrent spontaneous abortions (RSAs). Recently, we reported that mesenchymal stem cells (MSCs) therapy could improve fetal survival and reduce the abortion rate in abortion-prone mice, although the precise mechanisms of this action are poorly understood. Since MSCs have been shown to exert immunomodulatory effects on the immune cells, especially DCs, this study was performed to investigate the capability of MSCs to modulate the frequency, maturation state, and phenotype of uterine DCs (uDCs) as a potential mechanism for the improvement of pregnancy outcome.

Materials and Methods

In this experimental study, adipose-derived MSCs were intraperitoneally administered to abortion-prone pregnant mice on the fourth day of gestation. On the day 13.5 of pregnancy, after the determination of abortion rates, the frequency, phenotype, and maturation state of uDCs were analyzed using flow cytometry.

Results

Our results indicated that the administration of MSCs, at the implantation window, could significantly decrease the abortion rate and besides, increase the frequency of uDCs. MSCs administration also remarkably decreased the expression of DCs maturation markers (MHC-II, CD86, and CD40) on uDCs. However, we did not find any difference in the expression of CD11b on uDCs in MSCs-treated compared to control mice.

Conclusion

Regarding the mutual role of uDCs in establishment of a particular immunological state required for appropriate implantation, proper maternal immune responses and development of successful pregnancy, it seems that the modulation of uDCs by MSCs could be considered as one of the main mechanisms responsible for the positive effect of MSCs on treatment of RSA.

Down-regulation of miR-378a-3p induces decidual cell apoptosis: a possible mechanism for early pregnancy loss

STUDY QUESTION

Do microRNAs (miRNAs) contribute to human early pregnancy loss (EPL)?

SUMMARY ANSWER

miR-378a-3p expression is regulated by progesterone and is down-regulated in ducidua of EPL patients which may contribute to decidual apoptosis through Caspase-3 activation.

WHAT IS KNOWN ALREADY

A variety of miRNAs have been demonstrated to be associated with the development of decidualization and placental formation. However, little has been reported on the roles of miRNA in the pathogenesis of EPL.

STUDY DESIGN, SIZE, DURATION

Normal and EPL decidual tissues were collected from patients with normal pregnancies undergoing elective termination of gestation, and from patients with EPL, respectively.

PARTICIPANTS/MATERIALS, SETTING, METHODS

miRNA microarrays were used to identify the differentially expressed miRNAs between normal and EPL decidua, and miRNA expression was confirmed by qRT-PCR, qRT-PCR, western blotting and luciferase reporter assays were employed to validate the downstream targets of miR-378a-3p. The effects of miR-378a-3p were evaluated using miR-378a-3p-transfected decidual cells.

MAIN RESULTS AND THE ROLE OF CHANCE

Of note, 32 up-regulated miRNAs and 38 down-regulated miRNAs were identified by microarray analysis when comparing EPL to normal decidua. MiR-378a-3p was significantly down-regulated in the EPL decidua and was found to inversely regulate the expression of Caspase-3 by directly binding to its 3'-UTRs. In decidual cells, transfection of miR-378a-3p mimics resulted in the inhibition of cell apoptosis and in the increase of cell proliferation through Caspase-3 suppression. Moreover, we found that progesterone could induce the expression of miR-378a-3p in decidual cells.

LIMITATIONS, REASONS FOR CAUTION

This study focused on the function of miR-378a-3p and its target Caspase-3, however, numerous other targets and miRNAs may also be responsible for the pathogenesis of EPL. Therefore, further studies are required to elucidate the role of miRNAs in EPL.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings indicate that miR-378a-3p may contribute to the development of EPL, and that it could serve as a new potential predictive and therapeutic target of progesterone-treatment for EPL.

STUDY FUNDING/COMPETING INTEREST

This study was supported by National Basic Research Program of China (No.2012CB944900); National Science Foundation of China (No.31471405 and 81490742, No.81361120246); The National Science and Technology Support Program (No.2012BA132B00). Authors declare no competing interests.

Opposing roles of inter-α-trypsin inhibitor heavy chain 4 in recurrent pregnancy loss

Background

The mechanism behind an increased risk of recurrent pregnancy loss (RPL) remains largely unknown. In our previous study, we identified that inter-α-trypsin inhibitor heavy chain 4 (ITI-H4) is highly expressed at a modified molecular weight of 36 kDa in serum derived from RPL patients. Yet, the precise molecular mechanism and pathways by which the short form of ITI-H4 carries out its function remain obscure.

Methods

Human sera and peripheral blood mononucleated cells (PBMCs) were collected from patients and normal controls to compare the expression levels of ITI-H4 and plasma kallikrein (KLKB1). Flow cytometric assay was performed to measure inflammatory markers in sera and culture supernatants. Furthermore, to investigate the functions of the two isoforms of ITI-H4, we performed migration, invasion, and proliferation assays.

Findings

In the current study, we showed that ITI-H4 as a biomarker of RPL could be regulated by KLKB1 through the IL-6 signaling cascade, indicating a novel regulatory system for inflammation in RPL. In addition, our study indicates that the two isoforms of ITI-H4 possess opposing functions on immune response, trophoblast invasion, and monocytes migration or proliferation.

Interpretation

The ITI-H4 (∆N⁶⁸⁸) might be a crucial inflammatory factor which contributes to the pathogenesis of RPL. Moreover, it is expected that this study would give some insights into potential functional mechanisms underlying RPL.

Fund

This study was supported by the Ministry of Health & Welfare of the Republic of Korea (HI18C0378) through the Korea Health Industry Development Institute.

Immunomodulatory effects of human amniotic epithelial cells on naive CD4+ T cells from women with unexplained recurrent spontaneous abortion

INTRODUCTION

Immune imbalance at the maternal-fetal interface plays a fundamental role in the pathogenesis of unexplained recurrent spontaneous abortion (URSA). Human amniotic epithelial cells (hAECs) possess pregnancy-friendly immunomodulatory effects. Here, we investigated how function of naive CD4⁺ T cells from URSA patients is affected by hAECs.

METHODS

Phenotypic characteristics of hAECs were determined by flow cytometry and their effect on proliferation of allogeneic peripheral blood mononuclear cells (PBMCs) was evaluated by a BrdU cell proliferation assay. Naive CD4⁺ T cells were isolated from 25 URSA patients and 5 healthy women and co-cultured with hAECs. Immunomodulatory effects of hAECs on cytokines profile, proliferation of stimulated CD4⁺ T cells and induction of regulatory T cells (Tregs) were assessed by ELISA and flow cytometry, respectively. Functional competency of Tregs was evaluated in an allogeneic mixed lymphocyte reaction (MLR) system.

RESULTS

hAECs did not elicit allogeneic proliferative responses of PBMCs, inhibited proliferation of naive CD4⁺ T cells, induced production of Th2 and suppressed production of Th1 and Th17 cytokines. hAECs showed the ability to induce differentiation of Tregs and production of transforming growth factor-beta1 (TGF-β1) and interleukin-10 (IL-10). This ability was found to be superior in control subjects compared to URSA patients. Indeed, Tregs generated in the presence of hAECs expressed higher levels of CTLA-4 compared to Tregs generated in their absence and restrained the proliferation of autologus PBMCs in MLR system.

CONCLUSION

Based on these findings, hAECs can be considered as one potential candidate in immunotherapy of patients with URSA.

Pregnancy complicated with PFAPA (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) syndrome: a case report

Background

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome has been considered as a childhood syndrome. The underlying etiology of PFAPA syndrome is unclear however, currently considered as auto-immune inflammatory disease. Recently, a few cases of adult-onset of PFAPA syndrome have been reported. However, there is no report about the successful management of pregnancy complicated with PFAPA syndrome.

Case presentation

The patient was a 31-year-old woman who developed recurrent episodes of high fever associated with cervical adenitis, pharyngitis and vomiting started 9 months after a delivery. She was diagnosed with PFAPA syndrome and cimetidine 800 mg/day was initiated. Since then, these symptoms got better. Cimetidine treatment was discontinued since she became pregnant (6 weeks of pregnancy). Except one febrile episode at 8 weeks gestation, she did not develop a febrile episode during pregnancy.

Peripheral blood Th1/Th2 ratio was decreased from the first trimester to the second trimester of pregnancy. Then again, the ratio was steadily elevated during the third trimester. At 38 weeks, she delivered a live born infant without any complication. Two months after delivery, she developed PFAPA syndrome again and cimetidine treatment was re-initiated. However, febrile episodes were not controlled well, and Th1/Th2 ratio was further elevated compared to pregnancy status. Colchicine 0.5 mg once a day was initiated. Symptoms were diminished and Th1/Th2 ratio was gradually decreased.

Conclusion

There was no case report of pregnancy complicated with PFAPA syndrome, though there were several reports of adult-onset PFAPA cases without pregnancy. The current case may be the first case report of a successful pregnancy complicated with PFAPA. In this case, PFAPA symptoms were ameliorated during pregnancy, but reappeared after delivery. We speculate that PFAPA syndrome, a Th1 type immune disorder, might be improved due to the Th1 to Th2 shifting, which was induced by pregnancy. It is necessary to investigate further about PFAPA syndrome with pregnancy and Th1/Th2 immune responses in the future.

Efficacy of Different Treatment Regimens for Antiphospholipid Syndrome-related Recurrent Spontaneous Abortion

Background:

Antiphospholipid syndrome (APS)-related immune factors are considered as an important cause of recurrent spontaneous abortion (RSA). Anticoagulant and anti-inflammatory treatments are believed to effectively improve adverse pregnancy outcomes by affecting the abnormal autoimmune response of the maternal-fetal interface. The aim of this study was to observe the clinical characteristics and treatment outcomes of anticoagulant regimens and anti-inflammatory plus anticoagulation regimens for APS-related RSA.

Methods:

APS-related RSA cases from September 2011 to September 2016 at Peking University Third Hospital were retrospectively analyzed. The patients were assigned to study group (anti-inflammation plus anticoagulation) and control group (simple anticoagulation). The incidence of repeat abortion, the incidence of placental dysfunction, the gestational weeks of pregnancy, and the mean weight of the fetus were observed.

Results:

The pregnancy and neonatal outcome indicators of the repeat pregnancy loss rate (11.11% vs. 22.70%), placental dysfunction-related diseases (6.35% vs. 15.60%), the mean birth weight of infants born after 24 weeks gestation (3152.41 ± 844.67 g vs. 2765.76 ± 816.40 g), full-term delivery weight (3456.28 ± 419.79 g vs. 3076.18 ± 518.79 g), the proportions of low birth weight infants (12.70% vs. 21.98%), and small for gestational age (6.35% vs. 14.18%) differed significantly between the study and control groups (all P < 0.05). The incidence of preterm delivery, term delivery, and stillbirth was not significantly different between the two groups, and there was no significant difference between the study and control groups in gestational age at birth (37.6 ± 3.3 weeks vs. 36.9 ± 3.2 weeks; P > 0.05).

Conclusion:

The anti-inflammatory and anticoagulation regimen is more effective than the simple anticoagulation regimen in the treatment of APS recurrent abortion.

Diminished Frequency of Menstrual and Peripheral Blood NKT-Like Cells in Patients With Unexplained Recurrent Spontaneous Abortion and Infertile Women

Systemic monitoring of immune system may not precisely outline the local immune status in the uterus. This survey is a continuation of our previous studies on potential usefulness of menstrual blood (MB) immunophenotyping as a tool for investigation of immunological disturbances in pregnancy-related disorders. Peripheral blood (PB) and MB from healthy fertile (n = 15), unexplained recurrent spontaneous abortion (URSA; n = 15), and unexplained infertile women (n = 8) were collected simultaneously in the second day of their menstrual cycle and frequency of natural killer T (NKT)-like cell subpopulations were assessed by flow cytometry. Menstrual blood of all experimental groups contained higher percentage of TCRαβ⁺, CD45RO⁺, and CD16^- NKT-like cells compared to corresponding PB. Frequency of MB NKT-like cells in unexplained infertile participants was lower than fertile and URSA groups. Compared to normal participants, patients with URSA had lower frequency of PB TCRαβ⁺ and higher CD16⁺, while in infertile woman frequencies of PB CD45RO⁺, CD45RO^-, CD16^-, IL17⁺, and MB CD45RO⁺ NKT-like cells were lower. Although, PB and MB seemingly have the same histological nature, our results showed that MB contained different composition of NKT-like subsets with different cytokine profiles and could be viewed as one potential biological sample for evaluation of patients with infertility and URSA.

VEGF may contribute to macrophage recruitment and M2 polarization in the decidua

It is increasingly evident that cytokines and growth factors produced in the decidua play a pivotal role in the regulation of the local immune microenvironment and the establishment of pregnancy. One of the major growth factors produced in the decidua is vascular endothelial growth factor (VEGF), which acts not only on endothelial cells, but also on multiple other cell types, including macrophages. We sought to determine whether decidua-derived VEGF affects macrophage recruitment and polarization using human endometrial/decidual tissue samples, primary human endometrial stromal cells (ESCs), and the human monocyte cell line THP1. In situ hybridization was used for assessment of local VEGF expression and immunohistochemistry was used for identification and localization of CD68-positive endometrial macrophages. Macrophage migration in culture was assessed using a transwell migration assay, and the various M1/M2 phenotypic markers and VEGF expression were assessed using quantitative real-time PCR (qRT-PCR). We found dramatic increases in both VEGF levels and macrophage numbers in the decidua during early pregnancy compared to the secretory phase endometrium (non-pregnant), with a significant increase in M2 macrophage markers, suggesting that M2 is the predominant macrophage phenotype in the decidua. However, decidual samples from preeclamptic pregnancies showed a significant shift in macrophage phenotype markers, with upregulation of M1 and downregulation of M2 markers. In THP1 cultures, VEGF treatment significantly enhanced macrophage migration and induced M1 macrophages to shift to an M2 phenotype. Moreover, treatment with conditioned media from decidualized ESCs induced changes in macrophage migration and polarization similar to that of VEGF treatment. These effects were abrogated by the addition of a potent VEGF inhibitor. Together these results suggest that decidual VEGF plays a significant role in macrophage recruitment and M2 polarization, and that inhibition of VEGF signaling may contribute to the shift in macrophage polarity observed in different pregnancy disorders, including preeclampsia.

Low-dose lymphocyte immunotherapy rebalances the peripheral blood Th1/Th2/Treg paradigm in patients with unexplained recurrent miscarriage

BACKGROUND

The published results regarding lymphocytes immunotherapy for unexplained recurrent miscarriage (uRM) patients are conflicting due to different screening criteria and therapeutic protocols. The objective of the present study is to evaluate the effectiveness of immunotherapy using low-dose lymphocytes in patients with uRM and Th1/Th2/Treg paradigm disorders.

METHODS

Sixty-four uRM patients who received low-dose lymphocytes immunotherapy served as the immunotherapy group, while the other 35 women who did not receive the treatment served as the control group. The proportions of peripheral blood Th1 cells, Th2 cells and Treg cells; and the concentration of TGF-β1 in serum were detected by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively, before and after the immunotherapy.

RESULTS

The proportion of Th1 cells was significantly decreased while the proportions of Th2 cells and Treg cells were significantly increased in immunotherapy group patients after treatment. In addition, the concentration of TGF-β1 in serum was significantly higher after immunotherapy than before. Forty-three uRM patients achieved pregnancy after receiving immunotherapy and 5 patients underwent miscarriages in the immunotherapy group (11.6%, 5/43), while 8 of the 23 pregnant patients experienced a miscarriage in the control group (34.8%, 8/23; p < 0.05).

CONCLUSIONS

Low-dose lymphocyte immunotherapy is beneficial for restoring balance in the Th1/Th2/Treg paradigm and improving pregnancy outcome in uRM patients.

TRIAL REGISTRATION

NCT03081325 . ClinicalTrials.gov . Retrospectively registered July 2015.

Mesenchymal Stem Cell Therapy Prevents Abortion in CBA/J × DBA/2 Mating

Immunological disorders are among the main causes of recurrent spontaneous abortions (RSAs). Mesenchymal stem cells (MSCs) have been shown to modulate various aspects of immune responses. It seems that MSCs may improve the immunological conditions in immune-mediated RSA. The aim of this study is the reduction of resorption in RSA mouse model through MSCs therapy. The adipose-derived MSCs were administered intraperitoneal to pregnant CBA/J mice on day 4.5 of gestation in abortion-prone matting. On day 13.5 of pregnancy, abortion rates were calculated and transforming growth factor-β (TGF-β), interleukin 10 (IL-10), interferon γ (IFN-γ), and tumor necrosis factor α (TNF-α) gene expression in deciduas were evaluated by real-time polymerase chain reaction (PCR). The level of TGF-β in serum was also determined by enzyme linked immunosorbent assay (ELISA) method. The obtained results showed that MSCs therapy could reduce the abortion rate significantly in test group compared to controls. MSCs therapy also caused a significant upregulation of TGF-β and IL-10 and downregulation of IFN-γ and TNF-α genes expression in deciduas. However, the levels of TGF-β didn't change in mice sera. Due to the significant decrease in abortion rate, we concluded that MSCs therapy could modulate the immune responses in fetomaternal interface and protect fetus from undesirable immune responses. So, these cells might be considered as a new therapeutic for spontaneous pregnancy loss. The local upregulation of TGF-β and IL-10 and downregulation of IFN-γ and TNF-α gene expression in decidua could be considered as one possible mechanism of immune regulation, which could protect the fetus.

Vitamin D-metabolic enzymes and related molecules: Expression at the maternal-conceptus interface and the role of vitamin D in endometrial gene expression in pigs

Vitamin D is a secosteroid hormone with many varied functions including regulation of blood calcium levels, cell proliferation, immunity, and reproduction in mammals. Vitamin D is activated by 25-hydroxylase (CYP2R1) and 1-alpha-hydroxylase (CYP27B1) and is degraded by 24-hydroxylase (CYP24A1). Vitamin D is transported by vitamin D-binding protein (group-specific component, GC) through the bloodstream and regulates cellular actions by binding to vitamin D receptor (VDR). In this study, we determined the expression and regulation of vitamin D-related molecules and the role of vitamin D at the maternal-conceptus interface in pigs. Vitamin D-metabolizing enzymes CYP2R1, CYP27B1, and CYP24A1, vitamin D binding protein GC, and vitamin D receptor VDR were expressed in the endometrium in a pregnancy stage-specific manner as well as in conceptus and chorioallantoic tissues during pregnancy. VDR protein was localized to endometrial and trophoblastic cells. Concentrations of calcitriol, the active form of vitamin D, in the endometrial tissues were higher during early pregnancy than in mid- to late pregnancy, while plasma concentrations of calcitriol were highest during late pregnancy. Furthermore, calcitriol affected the expression of several genes related to conceptus implantation, vitamin D metabolism, calcium ion regulation, PG metabolism, and calcium-binding proteins in endometrial tissue explants. These results show that CYP2R1, CYP27B1, CYP24A1, GC, and VDR were expressed at the maternal-conceptus interface, endometrial calcitriol levels were regulated during pregnancy, and calcitriol modulated the expression of endometrial genes, suggesting that calcitriol may play an important role in the establishment and maintenance of pregnancy by regulating endometrial function in pigs.

Uterine CD56dim and CD16+ Cells in Refractory Antiphospholipid Antibody-Related Pregnancy Loss and Chromosomally Intact Abortuses: A Case-Control Study

AIM

To evaluate the role of uterine natural killer (uNK) CD56^dim and CD16⁺ cells in patients with refractory antiphospholipid, antibody-mediated, recurrent, pregnancy loss.

SETTINGS AND DESIGN

A case-control study was conducted between 2012 and 2015 at a university hospital.

PATIENTS AND METHODS

A group of 118 women with a history of antiphospholipid antibody syndrome experiencing fetal loss in spite of low dose aspirin (LDA) and low molecular weight heparin (LMWH) treatment in the current pregnancy were included in this study. A group of 32 patients undergoing an elective termination of viable pregnancies before 20 weeks were taken as controls. Suction evacuation was performed to collect abortus specimens, and uterine wall curettage was performed to collect decidua specimens, which were then stained using monoclonal antibodies specific to CD56 and CD16.

STATISTICS

Statistical analyses were performed using the Statistical Package for the Social Sciences version 18 software. Chi-square and Fisher exact tests were used for making comparison between the groups.

RESULTS

Abnormal fetal karyotype was found in nine (9/97) cases of the study group, which means that abnormal karyotype accounts for only 9.3% of the causes of failure of treatment. Abnormal karyotype was found in four cases of the control group. Only cases with normal karyotyping were subjected to decidual uNK cells analysis. We found that CD56^dim and CD16⁺ were found in the decidua of 79 cases (79/97), which means that aberrant natural killer cells expression might account for 81.4% of the cases of refractory antiphospholipid antibody (APA)-mediated recurrent pregnancy loss.

CONCLUSION

CD56^dim and CD16⁺ uNK cells might be correlated with refractory APA-mediated recurrent pregnancy loss.

Inflammation-induced fetal growth restriction in rats is associated with increased placental HIF-1α accumulation

Introduction

Hypoxia-inducible factor 1-alpha (HIF-1α) is the oxygen-sensitive subunit of the transcription factor HIF-1, and its expression is increased in placentas from pregnancies complicated by pre-eclampsia (PE). Fetal growth restriction (FGR) and PE often share a common pathophysiology; however, it is unknown whether increased placental HIF-1α occurs in FGR. We previously demonstrated that aberrant maternal inflammation in rats resulted in altered utero-placental perfusion and FGR, both of which were prevented by administration of the nitric oxide mimetic glyceryl trinitrate (GTN). Our aim here was to determine whether abnormal maternal inflammation causing FGR is linked to placental HIF-1α accumulation and whether GTN administration could prevent increases in placental HIF-1α.

Methods

Levels of inflammatory factors in maternal plasma were measured using a multiplex assay after an injection of low-dose lipopolysaccharide (LPS) to rats on gestational day (GD) 13.5. Following three additional daily LPS injections from GD14.5–16.5, GD17.5 placentas were harvested for HIF-1α immunolocalisation; serial sections were also stained for the hypoxia marker pimonidazole. A subset of rats received LPS injections along with GTN delivered continuously (25 μg/h via a transdermal patch) on GD12.5-GD17.5.

Results

Within two hours of LPS administration, levels of maternal pro-inflammatory cytokines were increased compared with saline-treated controls. GD17.5 placentas of growth-restricted fetuses exhibited increased HIF-1α accumulation; however, this did not correlate with pimonidazole staining for which no differences were observed between groups. Furthermore, the LPS-mediated increases in maternal inflammatory cytokine levels and placental HIF-1α accumulation did not occur in rats treated with GTN.

Discussion

Our results demonstrate that inflammation-induced FGR is associated with increased placental HIF-1α accumulation; however, expression of this transcription factor may not correlate with regions of hypoxia in late-gestation placentas. The GTN-mediated attenuation of placental HIF-1α accumulation in LPS-treated rats provides insight into the mechanism by which GTN improves inflammation-induced complications of pregnancy.

Smoking, HIV, and risk of pregnancy loss

OBJECTIVE

Cigarette smoking during pregnancy increases risks of poor pregnancy outcomes including miscarriage and stillbirth (pregnancy loss), but the effect of smoking on pregnancy loss among HIV-infected women has not been explored. Here, investigated the impact of smoking on risk of pregnancy loss among HIV-positive and HIV-negative women, and estimated the potential impact of realistic smoking cessation interventions on risk of pregnancy loss among HIV-positive women.

DESIGN

We analyzed pregnancy outcomes in HIV-positive and HIV-negative participants in the Women's Interagency HIV Study between 1994 and 2014.

METHODS

We estimated effects of current smoking at or immediately before pregnancy on pregnancy loss; we controlled for confounding using regression approaches, and estimated potential impact of realistic smoking cessation interventions using a semiparametric g-formula approach.

RESULTS

Analysis examined 1033 pregnancies among 659 women. The effect of smoking on pregnancy loss differed dramatically by HIV status: adjusted for confounding, the risk difference comparing current smokers to current nonsmokers was 19.2% (95% confidence limit 10.9-27.5%) in HIV-positive women and 9.7% (95% confidence limit 0.0-19.4%) in HIV-negative women. These results were robust to sensitivity analyses. We estimated that we would need to offer a realistic smoking cessation intervention to 36 women to prevent one pregnancy loss.

CONCLUSION

Smoking is a highly prevalent exposure with important consequences for pregnancy in HIV-positive pregnant women in the United States, even in the presence of potent highly active antiretroviral therapy. This evidence supports greater efforts to promote smoking cessation interventions among HIV-positive women, especially those who desire to become pregnant.

Association between Genetic Polymorphisms in Interleukin Genes and Recurrent Pregnancy Loss - A Systematic Review and Meta-Analysis

Interleukins are a group of immunomodulatory proteins that mediate a variety of immune reactions in the human body. To investigate the association between interleukin gene polymorphisms and recurrent pregnancy loss (RPL), we reviewed 21 studies from MEDLINE, EMBASE, OVID SP and PubMed to evaluate RPL-related interleukin gene polymorphisms. Meta-analysis was performed on 12 of the polymorphisms, and a review included the others. Our integrated results indicated that IL-1β (-511C/T) (P = 0.02, 95% CI 0.77[0.62,0.96]), IL-6 (-634C/G) (P<0.001, 95% CI 2.91[2.01,4.22]), IL-10 (-1082G/A, -819T/C) (P = 0.01, 95% CI 0.80[0.67,0.96]; P<0.01, 95% CI 0.66[0.49,0.89]), and IL-18 (-137G/C, -105G/A) (P<0.01, 95% CI 1.69[1.24,2.31]; P = <0.01, 95% CI 1.41[1.17,1.70]) consistently associated with RPL after meta-analysis. IL-17A rs2275913 and IL-17F rs763780, IL-21 rs2055979 and rs13143866, IL-1β (-31C/T), IL-6 (-2954G/C), and IL-10 (-536A/G) were reported only once as having a significant association with RPL. The potential mechanism underlying miscarriage and these polymorphisms and future research directions are also discussed.

Citrullination regulates the expression of insulin-like growth factor-binding protein 1 (IGFBP1) in ovine uterine luminal epithelial cells

There are five peptidylarginine deiminase (PAD) isozymes designated as PADs 1, 2, 3, 4 and 6, and many are expressed in female reproductive tissues. These enzymes post-translationally convert positively charged arginine amino acids into neutral citrulline residues. Targets for PAD-catalyzed citrullination include arginine residues on histone tails, which results in chromatin decondensation and changes in gene expression. Some of the first studies examining PADs found that they are localized to rodent uterine epithelial cells. Despite these findings, the function of PAD-catalyzed citrullination in uterine epithelial cells is still unknown. To address this, we first examined PAD expression in uterine cross-sections from pregnant ewes on gestation day 25 (d25). Immunohistochemistry revealed that the levels of PADs 2 and 4 are robust in luminal and glandular epithelia compared with those of PADs 1 and 3. As PADs 2 and 4 have well-characterized roles in histone citrullination, we next hypothesized that PADs citrullinate histones in these uterine cells. Examination of caruncle lysates from pregnant ewes on gestation d25 and an ovine luminal epithelial (OLE) cell line shows that histone H3 arginine residues 2, 8, 17 and 26 are citrullinated, but histone H4 arginine 3 is not. Using a pan-PAD inhibitor, we next attenuated histone citrullination in OLE cells, which resulted in a significant decrease in the expression of insulin-like growth factor-binding protein 1 (IGFBP1) mRNA. As IGFBP1 is important for the migration and attachment of the trophectoderm to uterine endometrium, our results suggest that PAD-catalyzed citrullination may be an important post-translational mechanism for the establishment of pregnancy in ewes.

Evaluation of serum concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-10, and nitric oxide (NO) during the estrous cycle, early pregnancy and abortion in goats

The aim of this study was to establish the serum concentrations, ranges, and trends of Th1 type cytokine (tumor necrosis factor (TNF)-α and interleukin (IL)-2), Th2 type cytokine (IL-10), and nitric oxide (NO) during the estrous cycle, early pregnancy and abortion in goats. Boer goats (n=25) having symptoms of normal estrous cycles were selected, 20 were mated and 15 conceived a pregnancy, and the remaining five were not mated and served as estrous controls. On the Day 60 of pregnancy, all 15 pregnant goats were induced to abort the pregnancy by intramuscular injection of prostaglandin (PG). Serum samples were collected on Days 1, 7, 14, and 19 of the estrous cycle, at Days 0, 10, 20, 30, 40, 50, and 60 of pregnancy, and at Days 1, 3, 8, 10 over the period when abortion were occurring. Results of the present study indicated that during the estrous cycle the balance between Th1 and Th2 cytokines slightly shifted toward Th1 cytokine production (TNF-α and IL-2). The NO may have a direct positive role in inducing a Th1 response. During early pregnancy, TNF-α and IL-2 serum concentrations markedly increased from Days 0 to 10, and gradually decreased from Days 10 to 60, while IL-10 and NO serum concentrations remained elevated from Days 0 to 60. The increased concentrations of IL-10 and decreased concentrations of TNF-α and IL-2 are characteristic of a Th2-enhanced response, which may be related to increased concentrations of NO. These changes may be essential to maintain a normal pregnancy. In addition, the serum concentrations of TNF-α, IL-2 and NO at Days 1, 3, 8 and 10 of the period of induced abortion were markedly greater than that on Day 60 of pregnancy. Conversely, IL-10 concentrations at these four time points of abortion were markedly less than that on Day 60 of pregnancy. After abortion, the Th2 response shifted to a Th1-enhanced response. Thus, NO concentrations increase and the Th1-enhanced response may function synergistically to be involved in physiologic responses that lead to abortion of the pregnancy. It is concluded that the serum concentrations of the Th1/Th2 cytokine and NO changed temporally as the estrous cycle, pregnancy and abortion progressed advanced. A Th2-enhanced state promoted normal pregnancy, while increased concentrations of Th1 were observed during the period of fetal abortion. The concentrations of NO varied in regulation of the Th1/Th2 cytokine concentration balance during the three phases (estrous cycle, pregnancy, and fetal abortion) of goats.

EPHB4, a down stream target of IFN-γ/STAT1 signal pathway, regulates endothelial activation possibly contributing to the development of preeclampsia

PROBLEM

Preeclampsia is characterized by endothelial activation and excessive inflammation, of which interferon (IFN)-γ is a potent inducer. Eph receptor B4 (EPHB4) also involved in endothelial activation in inflammation. Their role and relationship in preeclampsia remain unclear.

METHOD OF STUDY

Intercellular adhesion molecular (ICAM)-1 was employed as the hallmark of endothelial activation. The serum levels of IFN-γ and the expression of EPHB4 and ICAM-1 were assessed by ELISA, qRT-PCR and WB, respectively. Primary human umbilical vein endothelial cells (HUVECs) were treated with IFN-γ of different concentration or for different times to determine the effect of IFN-γ on EPHB4 and ICAM-1 expression. Overexpression and shRNA constructs, chromatin immunoprecipitation (ChIP) and luciferase assays were conducted to clarify the regulation mechanism of IFN-γ/STAT1 on EPHB4 resulting in HUVECs activation. Endothelial-trophoblast co-culture model was used to illustrate the role of EPHB4 in the process of activated endothelial cells resisting trophoblast invasion.

RESULTS

IFN-γ, EPHB4 and ICAM-1 expression were elevated in preeclampsia. IFN-γ induced HUVECs activation through EPHB4 expression. ChIP and luciferase assays revealed that IFN-γ promoted EPHB4 transcription by STAT-1 binding to EPHB4 promoter. EPHB4 probably involved in resisting trophoblasts displacement by IFN-γ-activated HUVECs.

CONCLUSION

This study uncovered the character of EPHB4-regulating endothelial activation in the pathogenesis of preeclampsia.

A shift in the balance of T17 and Treg cells in menstrual blood of women with unexplained recurrent spontaneous abortion

To determine usefulness of menstrual blood for assessment of differential frequency of T cell subsets, peripheral blood (PB) and menstrual blood (MB) from healthy fertile (n=15), unexplained recurrent spontaneous abortion (URSA) women (n=15) and unexplained infertile women (n=8) were collected in the second day of menstrual bleeding. Frequency of T cell subsets was measured by flow cytometry. URSA and unexplained infertile patients had higher frequency of TCRαβ(+)CD3(+)CD56(-) and CD45RO(+) T cells as well as CD45RO(+)/CD45RO(-) ratio in PB as compared to MB. Frequency of CD3(+)TCRγδ(+) cells in PB of unexplained infertile and MB of URSA patients were significantly lower than that in fertile group. In all groups MB contained higher percentage of CD4(+)CD25(+)Foxp3(+) regulatory and lower percentages of CD16(+) T cells compared to PB. T17 cells (CD3(+)CD56(-)IL-17(+)) was found to be significantly higher in MB of only fertile and unexplained infertile subjects and not URSA patients in comparison with PB. Compared to PB, only fertile women had higher T17:Treg ratio in their MB. URSA women had significantly lower MB T17 cells and T17:Treg ratio compared to those in fertile and unexplained infertile women. Based on the findings presented here, we speculate that MB has its own unique immune milieu which is not solely continuation of the immune environment of secretory endometrium. Indeed, immunophenotyping of MB immune cells could potentially be a useful tool for investigation of immunological disturbances in pregnancy-related disorders.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG (S1-Level, AWMF Registry No. 015/050, December 2013)

Purpose: Official guideline coordinated and published by the German Society of Gynecology and Obstetrics (DGGG). Aim of the guideline was to standardize the diagnosis and treatment of patients with recurrent miscarriage (RM). Recommendations were proposed, based on the current national and international literature and the experience of the involved physicians. Consistent definitions, objective assessments and standardized therapy were applied. Methods: Members of the different involved societies developed a consensus in an informal process based on the current literature. The consensus was subsequently approved by the heads of the scientific societies. Recommendations: Recommendations for the diagnosis and treatment of patients with RM were compiled which took the importance of established risk factors such as chromosomal, anatomical, endocrine, hemostatic, psychological, infectious and immunological disorders into consideration.

Uterine blood flow indices, antinuclear autoantibodies and unexplained recurrent miscarriage

OBJECTIVE

To study the correlation between 2D and 3D uterine flow indexes and the presence or the absence of antinuclear antibodies (ANA) in women with unexplained recurrent miscarriage (uRM).

METHODS

Fifty-two subjects (26 uRM and 26 control women) underwent 2D Doppler measurement of pulsatility index and resistance index of the uterine arteries in both the follicular and midluteal phase of the cycle. Additionally, 3D ultrasonography determination of vascularisation index, flow index, and vascularisation flow index was carried out with the aid of the VOCAL technique. Serum assay for the presence of ANA was performed in all women.

RESULTS

Pulsatility index of ANA+ uRM women was higher than that of ANA- uRM women and control ANA+ and ANAwomen, both in the follicular and in the midluteal phase of the cycle. Vascularisation index in ANA- uRM women was significantly higher than that in ANA+ control women. Flow index in uRM ANA+ women was significantly lower than that of each of the other groups.

CONCLUSION

ANA might be involved in uRM by determining an impairment in uterine blood flow hemodynamic, particularly in uterine blood flow intensity and uterine artery impedance.

Association between IL-6 -174 G/C, IL-6 -634 G/C, and IFN-γ +874 A/T polymorphisms and susceptibility to recurrent pregnancy loss: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether interleukin-6 (IL-6) -174 G/C, IL-6 -634 G/C, and interferon-γ (IFN-γ) +874 A/T polymorphisms are associated with susceptibility to recurrent pregnancy loss (RPL).

METHODS

We conducted a literature search using PubMed and EMBASE databases and performed a meta-analysis using fixed- or random-effects models.

RESULTS

A total of 15 articles met the study inclusion criteria. When all study subjects were considered together, meta-analysis showed no association between RPL and the IL-6 -174 GG + GC genotype (odds ratio [OR] = 0.794, 95 % confidence interval [CI] = 0.542-1.163, p = 0.236). However, stratification of the data by ethnicity indicated an association between this genotype and RPL in non-Caucasians (OR = 0.528, 95 % CI = 0.302-0.925, p = 0.028), but not in Caucasian populations. Moreover, meta-analysis revealed an association between RPL and the IL-6 -634 GG + GC genotype in all study subjects (OR = 0.556, 95 % CI = 0.383-0.806, p = 0.002), while stratification by ethnicity revealed a negative association between this genotype and RPL in Asian (OR = 0.545, 95 % CI = 0.371-0.800, p = 0.002) but not Middle Eastern populations. Furthermore, a relationship between the IFN-γ +874 A allele and RPL was identified in non-Caucasians (OR = 1.403, 95 % CI = 1.133-1.734, p = 0.002), but not in Caucasians.

CONCLUSIONS

This meta-analysis demonstrates that IL-6 -174 G/C, IL-6 -634 G/C, and IFN-γ +874 A/T polymorphisms are associated with susceptibility to RPL, particularly in non-Caucasians.