Characterization of the subsets of human NKT-like cells and the expression of Th1/Th2 cytokines in patients with unexplained recurrent spontaneous abortion

The positive impact of targeted modulating food intolerance on immune-related recurrent pregnancy loss

BACKGROUND

It has been proven that immune disorders are one of the vital risk factors of recurrent pregnancy loss (RPL), and the presence of food intolerance seems to play an essential role in this. However, the impact of immune status induced by food intolerance on RPL has not been reported. This study utilized a targeted diet avoiding food intolerance as much as possible for each participant to investigate their effects on pregnancy outcomes in RPL patients with positive autoimmune markers.

METHODS

From January 2020 to May 2021, fifty-eight patients with RPL were enrolled. They were divided into two groups based on the presence of autoantibodies: the autoantibody-positive group (AP, n = 29) and the autoantibody-negative group (AN, n = 29). Their food-specific immunoglobulin (Ig) G antibodies for 90 foods were tested using enzyme-linked immunosorbent assay (ELISA). The levels of immune parameters and the presence of gastrointestinal discomforts (diarrhea or constipation, eczema, and mouth ulcers) were recorded before and after dietary conditioning, followed by the analysis of pregnancy outcomes.

RESULTS

Compared to the AN group, the patients in the AP group showed immune disorders at baseline, such as reduced levels of IL-4 and complement C3, and increased levels of IL-2 and total B cells. These parameters within the AP group were significantly improved after dietary conditioning that avoided food intolerance, while no significant changes were observed in the AN group. Patients in the AP group had significantly higher food-specific IgG antibodies for cow's milk (89.66% vs. 48.28%, p < .001), yolk (86.21% vs. 27.59%, p < .001), bamboo shoots (86.21% vs. 44.83%, p < .001) compared to those in the AN group. Additionally, gastrointestinal discomforts including diarrhea or constipation, eczema, and mouth ulcers were more common in the AP group than in the AN group. After 3-month dietary conditioning, these significantly improved characteristics were only observed in the AP group (p < .001). Finally, the baby-holding rate was higher in the AP group compared to the AN group (p < .05).

CONCLUSIONS

The RPL patients in the AN group did not exhibit immune disorders, whereas those in the AP group experienced immune disorders and gastrointestinal discomforts. For patient with positive autoantibodies, dietary intervention may mitigate immune disorders and gastrointestinal discomforts, presenting a promising approach to enhance pregnancy outcomes.

Immunologic insights in recurrent spontaneous abortion: Molecular mechanisms and therapeutic interventions

Recurrent spontaneous abortion refers to the occurrence of two or more spontaneous abortions before or during the early stages of pregnancy. The immune system plays a crucial role in the maintenance of pregnancy and embryo implantation. Various immune cells, cytokines, and immune regulatory pathways are involved in the complex immune balance required for a stable pregnancy. Studies suggest that immune abnormalities may be associated with some recurrent spontaneous abortion cases, particularly those involving the dysregulation of immune cell function, autoimmune responses, and placental immunity. In terms of treatment, interventions targeting immune mechanisms are crucial. Various therapeutic approaches, including immunomodulatory drugs, immunoadsorption therapies, and immunocellular therapies, are continually being researched and developed. These approaches aim to restore the immune balance, enhance the success rate of pregnancies, and provide more effective treatment options for patients with recurrent spontaneous abortion.

Role of maternal-fetal immune tolerance in the establishment and maintenance of pregnancy

ABSTRACT

Normal pregnancy is a contradictory and complicated physiological process. Although the fetus carries the human leukocyte antigen (HLA) inherited from the paternal line, it does not cause maternal immune rejection. As the only exception to immunological principles, maternal-fetal immune tolerance has been a reproductive immunology focus. In early pregnancy, fetal extravillous trophoblast cells (EVTs) invade decidual tissues and come into direct contact with maternal decidual immune cells (DICs) and decidual stromal cells (DSCs) to establish a sophisticated maternal-fetal crosstalk. This study reviews previous research results and focuses on the establishment and maintenance mechanism of maternal-fetal tolerance based on maternal-fetal crosstalk. Insights into maternal-fetal tolerance will not only improve understanding of normal pregnancy but will also contribute to novel therapeutic strategies for recurrent spontaneous abortion, pre-eclampsia, and premature birth.

A preliminary study unveils CISD2 as a ferroptosis-related therapeutic target for recurrent spontaneous abortion through immunological analysis and two-sample mendelian randomization

Recurrent spontaneous abortion (RSA) affects approximately 1 % of women striving for conception, posing a significant clinical challenge. This study aimed to identify a prognostic signature in RSA and elucidate its molecular mechanisms. Prognostic gene impacts were further assessed in HTR-8/SVneo and human primary extravillous trophoblast (EVT) cells in vitro experiments. A total of 6168 differentially expressed genes (DEGs) were identified, including 3035 upregulated and 3133 downregulated genes. WGCNA pinpointed 8 significant modules and 31 ferroptosis-related DEGs in RSA. Optimal clustering classified RSA patients into three distinct subgroups, showing notable differences in immune cell composition. Six feature genes (AEBP2, CISD2, PML, RGS4, SRSF9, STK11) were identified. The diagnostic model showed high predictive capabilities (AUC: 0.966). Mendelian randomization indicated a significant association between CISD2 levels and RSA (OR: 1.069, P-value: 0.049). Furthermore, the downregulation of CISD2 promotes ferroptosis in HTR-8/SVneo and human primary EVT cells. CISD2 emerged as a pivotal gene in RSA, serving as a ferroptosis-related therapeutic target. The diagnostic model based on gene expression and Mendelian randomization provides novel insights into the pathogenesis of RSA.

Identification of hub genes in placental dysfunction and recurrent pregnancy loss through transcriptome data mining: A meta-analysis

Recurrent pregnancy loss (RPL) is a condition characterized by the loss of two or more pregnancies before 20 weeks of gestation. The causes of RPL are complex and can be due to a variety of factors, including genetic, immunological, hormonal, and environmental factors. This transcriptome data mining study was done to explore the differentially expressed genes (DEGs) and related pathways responsible for pathogenesis of RPL using an Insilco approach. RNAseq datasets from the Gene Expression Omnibus (GEO) database was used to extract RNAseq datasets of RPL. Meta-analysis was done by ExpressAnalyst. The functional and pathway enrichment analysis of DEGs were performed using KEGG and BINGO plugin of Cytoscape software. Protein-protein interaction was done using STRING and hub genes were identified. A total of 91 DEGs were identified, out of which 10 were downregulated and 81 were upregulated. Pathway analysis indicated that majority of DEGs were enriched in immunological pathways (IL-17 signalling pathway, TLR-signalling pathway, autoimmune thyroid disease), angiogenic VEGF-signalling pathway and cell-cycle signalling pathways. Of these, 10 hub genes with high connectivity were selected (CXCL8, CCND1, FOS, PTGS2, CTLA4, THBS1, MMP2, KDR, and CD80). Most of these genes are involved in maintenance of immune response at maternal-fetal interface. Further, in functional enrichment analyses revealed the highest node size in regulation of biological processes followed by cellular processes, their regulation and regulation of multicellular organismal process. This in-silico transcriptomics meta-analysis findings could potentially contribute in identifying novel biomarkers and therapeutic targets for RPL, which could lead to the development of new diagnostic and therapeutic strategies for this condition.

Exploring Natural Killer Cell Testing in Embryo Implantation and Reproductive Failure: An Overview of Techniques and Controversies

The blastocyst nidation is the most crucial stage to a successful pregnancy, as the white cells work to promote a favorable endometrial microenvironment for this process. Intriguingly, this implantation window lasts, on average, 6 days in most regular women, and its quality is affected by many pathological conditions. Since the grounds of reproductive failure in healthy couples are still uncharted, studies have widely suggested a potential hostile role of the immune system in the equilibrium of the maternal-fetal interface. In recent years, natural killer cells have been the highlight as they represent the greatest lymphocyte in the uterus and have immune surveillance through cytotoxicity during the implantation window. This review explored the main techniques used for natural killer (NK) cell testing in the implantation window over the last 13 years on the PubMed® database. Of 2167 published articles potentially relevant for the review, only thirty-three were about cell evaluation in healthy women, met the inclusion criteria, and had their methodology critically analyzed. Here, we bring a summary from the study group and sample collection to evidence comments about their findings and correlations. Meanwhile, we also summarize the current relationship between NK cells and endometrial receptivity with reproductive failure to help enhance the possibilities for future research. In conclusion, our overview points out that restricted and unstandardized methods support the controversy between the NK population and unsuccessful embryo implantation, which is an obstacle to studying why healthy eggs do not thrive and finding a solution for one of the most controversial topics in human reproduction.

Association of recurrent implantation failure and recurrent pregnancy loss with peripheral blood natural killer cells and interferon-gamma level

OBJECTIVE

Fetal uterine survival depends on maintaining an immune balance between the mother and fetus. This study aimed to investigate the correlation of blood peripheral natural killer (NK) cells and interferon-gamma (IFN-γ) with recurrent recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL).

METHODS

In this case-control study, peripheral blood samples were obtained from three groups of RPL, RIF, and parous women without a history of abortion or infertility problems and analyzed by lymphocyte-based flow cytometry. Afterward, the levels of NK cells and IFN-γ were determined. All data were analyzed using one-way analysis of variance and nonparametric Kruskal-Wallis tests.

RESULTS

The level of IFN-γ in the RPL group was significantly higher than that in parous women and the RIF group (P<0.05), whereas its level in the RIF group was not significantly different from the control group (P>0.05). A significant correlation was found between the levels of IFN-γ and NK cells in the RPL group (r=0.481; P=0.02). However, no significant correlation was found between the levels of IFN-γ and the active NK cells in the RPL group (P=0.08). Moreover, no significant correlation was found between the levels of NK cells (whether activated or not) and IFN-γ in the RIF patients (P>0.05).

CONCLUSION

Immune dysfunction may not be involved in implantation failure during IVF but may be involved in recurrent miscarriage, probably by increasing IFN-γ levels.

The role of miRNA molecules in the miscarriage process

The etiology and pathogenesis of miscarriage, which is the most common pregnancy complication, have not been fully elucidated. There is a constant search for new screening biomarkers that would allow for the early diagnosis of disorders associated with pregnancy pathology. The profiling of microRNA expression is a promising research area, which can help establish the predictive factors for pregnancy diseases. Molecules of microRNAs are involved in several processes crucial for the development and functioning of the body. These processes include cell division and differentiation, programmed cell death, blood vessel formation or tumorigenesis, and the response to oxidative stress. The microRNAs affect the number of individual proteins in the body due to their ability to regulate gene expression at the post-transcriptional level, ensuring the normal course of many cellular processes. Based on the scientific facts available, this paper presents a compendium on the role of microRNA molecules in the miscarriage process. The expression of potential microRNA molecules as early minimally invasive diagnostic biomarkers may be evaluated as early as the first weeks of pregnancy and may constitute a monitoring factor in the individual clinical care of women in early pregnancy, especially after the first miscarriage. To summarize, the described scientific data set a new direction of research in the development of preventive care and prognostic monitoring of the course of pregnancy.

Pregnancy rates and clinical outcomes among women living with HIV enrolled in HPTN 052

HPTN 052 was a multi-country clinical trial of cART for preventing heterosexual HIV-1 transmission. The study allowed participation of pregnant women and provided access to cART and contraceptives. We explored associations between pregnancy and clinical measures of HIV disease stage and progression. Of 869 women followed for 5.70 (SD = 1.62) years, 94.7% were married/cohabitating, 96% initiated cART, and 76.3% had >2 past pregnancies. Of 337 women who experienced pregnancy, 89.3% were from countries with lower contraceptive coverage, 56.1% first started cART with PI-based regimens and 57.6% were 25-34 years old. Mean cART duration and condom use were similar among pregnant and nonpregnant individuals. Adjusting for confounders, viral load suppression (VLS) was not (aHR(CI) = 0.82(0.61, 1.08)) and CD4 was slightly associated with decreased rates of first pregnancy over time (aHR(CI) = 0.9(0.84, 0.95)); baseline VLS was associated with increased (aRR(CI) = 2.48(1.71, 3.59)) and baseline CD4 was slightly associated with decreased number of pregnancies (aRR(CI) = 0.9(0.85,0.96)) over study duration. Partner seroconversion was univariably associated with higher rates of first pregnancy (HR(CI) = 2.02(1.32,3.07)). Despite a background of higher maternal morbidity and mortality rates, our findings suggest that becoming pregnant does not pose a threat to maternal health in women with HIV when there is access to medical care and antiretroviral treatment.

Immune phenotype of the endometrium in patients with recurrent implantation failures after the transfer of genetically tested embryos in assisted reproductive technology programs

Recurrent implantation failures (RIF) in assisted reproduction programs are one of the most challenging problems. Among the factors that can adversely affect implantation, endometrial immune structural disorders may be one of the leading causes. The aim of our work was to study the immune features of the endometrium in women with RIF after genetically tested embryo transfer in comparison with fertile gestational carriers. Immune cells in endometrial samples were studied by flow cytometry and RNA expression of IL (interleukin)15, IL18, fibroblast growth factor-inducible 14 receptor (Fn14), and tumor necrosis factor-like weak inducer of apoptosis (TWEAK) by reverse polymerase chain reaction. In one-third of the cases, a unique immune profile of the endometrium, which we called the not transformed endometrial immune phenotype, was found. It is characterized by a combination of features, such as high expression of HLA-DR on natural killers (NK), increased fraction of CD16 + , and a decreased fraction of CD56bright endometrial NK. In addition, when compared to gestational carriers, patients with RIF had a greater discrepancy between IL18 mRNA expression data, reduced mean TWEAK and Fn14 levels, and increased IL18/TWEAK and IL15/Fn14 ratios. Immune abnormalities that were found in more than half of the patients (66.7 %) may be the cause of implantation failures in genetically tested embryo transfer programs.

Recent insight into autophagy and immunity at the maternal-fetal interface

Autophagy is a lysosomal degradation pathway that supports metabolic adaptation and energy cycling. It is essential for cell homeostasis, differentiation, development, and survival. Recent studies have shown that autophagy could influence immune responses by regulating immune cell functions. Reciprocally, immune cells strongly influence autophagy. Immune cells at the maternal-fetal interface are thought to play essential roles in pregnancy. Here, we review the induction of autophagy at the maternal-fetal interface and its role in decidualization and placental development. Additionally, we emphasize the role of autophagy in the immune microenvironment at the maternal-fetal interface, including innate immunity, adaptive immunity, and immune tolerance molecules. It also suggests new research directions and prospects.

Potential Therapeutic Effects of Human Amniotic Epithelial Cells on Gynecological Disorders Leading to Infertility or Abortion

The induction of feto-maternal tolerance, fetal non-immunogenicity, and the regulation of mother's immune system are essential variables in a successful pregnancy. Fetal membranes have been used as a source of stem cells and biological components in recent decades. Human amniotic epithelial cells (hAEC) have stem/progenitor characteristics like those found in the amniotic membrane. Based on their immunomodulatory capabilities, recent studies have focused on the experimental and therapeutic applications of hAECs in allograft transplantation, autoimmune disorders, and gynecological problems such as recurrent spontaneous abortion (RSA), recurrent implantation failure (RIF), and premature ovarian failure (POF). This review discusses some of the immunomodulatory features and therapeutic potential of hAECs in preventing infertility, miscarriage, and implantation failure by controlling the maternal immune system.

CD8+ and CD8- NKT Cells Exhibit Phenotypic Changes During Pregnancy

BACKGROUND

NKT cell population is a relatively well-characterized immune cell subset. Numerous publications have characterized the phenotypical features of its subpopulations even in human pregnancy. Nevertheless, there have not been studies investigating the distribution of the NKT cells based on the surface presence of the CD8 receptor.

METHODS

Thirty-four pregnant women from the first trimester, 30 from the second, and 36 from the third trimester of pregnancy in addition to 35 healthy non-pregnant women have been involved in the study. PBMCs were isolated from peripheral blood, CD8+ and CD8- NKT cells were then studied by flow cytometry using monoclonal antibodies. Immune checkpoint molecules and intracellular markers were also measured.

RESULTS

Substantial differences were revealed in the proportions of the NKT cell subpopulations in the healthy control cohort and the pregnant groups. By comparing the investigated groups, significant changes were detected in the expression levels of PD-L1, TIGIT, CD155, and NKG2D. Further associations were observed through examination of the relative expressions of TIGIT and CD226 in the CD8+ NKT subset.

CONCLUSION

Data suggest that the CD8+ NKT cells are under fine regulation during healthy human pregnancy.

The Update Immune-Regulatory Role of Pro- and Anti-Inflammatory Cytokines in Recurrent Pregnancy Losses

Recurrent pregnancy losses (RPL) is a common reproductive disorder with various underlying etiologies. In recent years, rapid progress has been made in exploring the immunological mechanisms for RPL. A propensity toward Th2 over Th1 and regulatory T (Treg) over Th17 immune responses may be advantageous for reproductive success. In women with RPL and animals prone to abortion, an inordinate expression of cytokines associated with implantation and early embryo development is present in the endometrium or decidua secreted from immune and non-immune cells. Hence, an adverse cytokine milieu at the maternal-fetal interface assaults immunological tolerance, leading to fetal rejection. Similar to T cells, NK cells can be categorized based on the characteristics of cytokines they secrete. Decidual NK (dNK) cells of RPL patients exhibited an increased NK1/NK2 ratio (IFN-γ/IL-4 producing NK cell ratios), leading to pro-inflammatory cytokine milieu and increased NK cell cytotoxicity. Genetic polymorphism may be the underlying etiologies for Th1 and Th17 propensity since it alters cytokine production. In addition, various hormones participate in cytokine regulations, including progesterone and estrogen, controlling cytokine balance in favor of the Th2 type. Consequently, the intricate regulation of cytokines and hormones may prevent the RPL of immune etiologies. Local or systemic administration of cytokines or their antagonists might help maintain adequate cytokine milieu, favoring Th2 over Th1 response or Treg over Th17 immune response in women with RPL. Herein, we provided an updated comprehensive review regarding the immune-regulatory role of pro- and anti-inflammatory cytokines in RPL. Understanding the roles of cytokines involved in RPL might significantly advance the early diagnosis, monitoring, and treatment of RPL.

Patterns of pregnancy loss among women living with and without HIV in Brazil, 2008-2018

BACKGROUND

Pregnancy loss is poorly understood, but infection may be a risk factor. Few studies have evaluated pregnancy loss among women living with HIV in the era of potent combination antiretroviral therapy.

OBJECTIVE

We hypothesize that maternal HIV and syphilis infection lead to increased risk of pregnancy loss, including both miscarriage and stillbirth. This study aimed to assess trends and possible predictors of spontaneous miscarriage and stillbirth among women living with HIV in a cohort of nearly 56,000 deliveries at a major referral institution in a city with the highest prevalence of HIV in Brazil.

STUDY DESIGN

Data from hospital records for women delivering from January 1, 2008 to December 31, 2018 were reviewed. Rates of stillbirth, miscarriage, and any pregnancy loss were compared using the Pearson chi-square test. Predictors of pregnancy loss were evaluated by robust univariate log-linear Poisson regression using a generalized estimating equations approach.

RESULTS

A total of 55,844 pregnancies were included in the analysis, with 54,308 pregnancies from 43,502 women without HIV and 1536 pregnancies from 1186 women living with HIV (seroprevalence of maternal HIV: 2.7%). Overall, 1130 stillbirths (2.0%) and 6558 miscarriages (11.7%) occurred. Any pregnancy loss was similar in both groups (13.8% in women without and 14.1% in women with HIV; P=.733). Stillbirth was higher among women living with HIV (3.4%) than among women without HIV (2.0%; P<.001), but there was no difference in overall miscarriage rates (10.7% in women with vs. 11.8% in women without HIV; P=.188). Women living with HIV had higher miscarriage rates between 12 and 20 weeks than women without HIV (34.8% vs 23.7%; P=.001), likely because of syphilis coinfection. Stillbirth rates were higher for women living with HIV from 2008 to 2014; however, a steady plateau was reached from 2014 to 2018, mirroring stillbirth rates in women without HIV. Maternal HIV infection did not increase the risk of miscarriage (relative risk, 0.90; 95% confidence interval, 0.77-1.05) or any pregnancy loss (relative risk, 1.00; 95% confidence interval, 0.88-1.15), but was associated with stillbirth (relative risk, 1.65; 95% confidence interval, 1.23-2.21). Maternal syphilis was associated with any pregnancy loss (relative risk, 1.24; 95% confidence interval, 1.11-1.38) and stillbirth (relative risk, 3.39; 95% confidence interval, 2.77-4.14), but not miscarriage (relative risk, 0.91; 95% confidence interval, 0.80-1.04).

CONCLUSION

In the era of combination antiretroviral therapy, there was no difference in miscarriage rates between women with and without HIV. HIV was associated with stillbirth risk but improved over time. Maternal syphilis was significantly associated with any pregnancy loss and stillbirth in all women. Syphilis is likely the main driver of pregnancy loss in women living with HIV in Brazil.

The peripheral and decidual immune cell profiles in women with recurrent pregnancy loss

Recurrent pregnancy loss (RPL) affects 1-2% of couples of reproductive age. Immunological analysis of the immune status in RPL patients might contribute to the diagnosis and treatment of RPL. However, the exact immune cell composition in RPL patients is still unclear. Here, we used flow cytometry to investigate the immune cell profiles of peripheral blood and decidual tissue of women who experienced RPL. We divided peripheral immune cells into 14 major subgroups, and the percentages of T, natural killer T (NKT)-like and B cells in peripheral blood were increased in RPL patients. The decidual immune cells were classified into 14 major subpopulations and the percentages of decidual T, NKT-like cells and CD11c^hi Mφ were increased, while those of CD56^hi decidual NK cells and CD11c^lo Mφ were decreased in RPL patients. The spearmen correlation analysis showed that the proportion of peripheral and decidual immune cells did not show significant correlations with occurrences of previous miscarriages. By using flow cytometry, we depicted the global peripheral and decidual immune landscape in RPL patients. The abnormalities of peripheral and decidual immune cells may be involved in RPL, but the correlations with the number of previous miscarriages need further verification.

Tumour necrosis factor inhibitor use during pregnancy is associated with increased birth weight of rheumatoid arthritis patients' offspring

OBJECTIVES

To study pregnancy outcomes in a closely monitored, well-defined cohort of women with rheumatoid arthritis (RA). In particular, pregnancy outcomes of women that used a TNFi during pregnancy.

METHODS

Patients were derived from a prospective study on pregnancy and RA (Preconception Counseling in Active RA study) and treated according to a treatment protocol aimed at minimal disease activity. Multivariate linear regression analysis was used to describe which variables influenced birth weight.

RESULTS

188 patients were included, 92 (48.9%) patients with RA used a TNFi during pregnancy. Disease Activity Score in 28 joints C reactive protein (DAS28CRP) was low at all time points during pregnancy (DAS28CRP in the third trimester: 2.17 (SD 0.73). TNFi use was not associated with an increase of adverse pregnancy outcomes such as low birth weight (<2500 g), (emergency) caesarian section, hypertensive disorders or congenital malformations. TNFi use resulted in less children born small-for-gestational age (p=0.05), however, did not increase the risk of large-for-gestational age (p=0.73). Mean birth weight was 173 g higher in women that used a TNFi during pregnancy (3.344 kg vs 3.171 kg, p=0.03). In the multivariate analysis, maternal age (β -0.023, 95% CI -0.040 to -0.0065, p=0.007), TNFi use (β 0.20, 95% CI 0.066, 0.34, p=0.004), diabetes mellitus (β 0.37, 95% CI 0.12, 0.63, p=0.004) and gestational age (β 0.18, 95% CI 0.15, 0.2, p<0.001) were statistically significant associated with birth weight.

CONCLUSIONS

This is the first study to show that TNFi use during pregnancy is associated with increased birth weight of offspring of women with well-controlled RA. The underlying mechanism of TNF-inhibition on birth weight and the long-term consequences for the offspring should be explored in future research.

Astilbin Improves Pregnancy Outcome in Rats with Recurrent Spontaneous Abortion by Regulating Th1/Th2 balance

OBJECTIVE

The purpose of this study was to investigate the effect of astilbin on pregnancy outcome in rats with recurrent spontaneous abortion (RSA).

METHODS

A total of 40 pregnant female Sprague Dawley rats were randomly divided into four groups: the control, model, astilbin, and prednisone groups. An RSA rat model was established by gavage with hydroxyurea and mifepristone. The number of surviving and reabsorbed embryos were counted on day 9 of gestation in each group. The rat serum was collected to detect the levels of IFN-γ, IL-2, IL-4, and IL-10 by enzyme-linked immunosorbent assay. The expressions of T-bet and GATA-3 in the decidual and placental tissues of the rats were determined by immunohistochemistry.

RESULTS

The absorptivity of embryos was significantly higher in the model group than in the control group. The levels of serum IFN-γ and IL-2 were significantly lower in the astilbin group than in the model group, while the levels of serum IL-4 and IL-10 were significantly higher. Astilbin treatment significantly increased GATA-3 expression, while it significantly reduced T-bet expression and the T-bet/GATA-3 ratio.

CONCLUSIONS

Astilbin has a therapeutic effect on RSA in rats by regulating the balance of Th1/Th2 in maternal circulation and likely in decidual tissue.

Association of Polymorphisms in miR146a, an Inflammation-Associated MicroRNA, with the Risk of Idiopathic Recurrent Spontaneous Miscarriage: A Case-Control Study

It has been established that microRNAs (miRNAs) are involved in the regulation of immune responses and serve as biomarkers of inflammatory diseases as well as recurrent spontaneous miscarriage (RSM). Herein, we aimed to study the relationship between three functional miR146a gene polymorphisms with idiopathic RSM (IRSM) susceptibility. We recruited 161 patients with IRSM and 177 healthy women with at least one live birth and without a history of abortion. Genotyping was performed using RFLP-PCR and ARMS-PCR methods. We found that the rs6864584 T/C decreased the risk of IRSM under dominant TT+TC vs. CC (OR = 0.029) and allelic C vs. T (OR = 0.028) contrast models. Regarding rs2961920 A/C and rs57095329 A/G polymorphisms, the enhanced risk of IRSM was observed under different genetic contrasted models, including the codominant CC vs. AA (OR = 2.81 for rs2961920) and codominant GG vs. AA (OR = 2.36 for rs57095329). After applying a Bonferroni correction, haplotype analysis revealed a 51% decreased risk of IRSM regarding the ACA genotype combination. This is the first study reporting that miR146a rs57095329 A/G, rs2961920A/C, and rs6864584 T/C polymorphisms are associated with the risk of IRSM in a southern Iranian population. Performing replicated case-control studies on other ethnicities is warranted to outline the precise effects of the studied variants on the risk of gestational trophoblastic disorders.

The Role of Dendritic Cell Subsets in Recurrent Spontaneous Abortion and the Regulatory Effect of Baicalin on It

Recurrent spontaneous abortion (RSA) is a relevant complication of pregnancy. Aberrant dendritic cell (DC) activities and differentiation have been identified to be involved in RSA, but the underlying mechanisms remain unclear. Baicalin from Radix Scutellariae possesses a wide range of pharmacological and biological activities. However, the effect of baicalin on DC function in RSA has not been investigated. Here, we analyzed the changes of peripheral and maternal-fetal interface DC subsets and function in patients and mice with RSA, respectively. Then, we further treated RSA mice with baicalin and analyzed the therapeutic effect and underlying mechanism. We found that DCs from the peripheral blood and decidua of RSA patients and the maternal-fetal of RSA mice were all polarized to conventional DCs, whose proportion was positively correlated with the mice embryo absorption rate. Moreover, DCs from RSA patients and mice showed increased expression of HLA-DR/MHC-II, CD80, and CD86 but decreased expression of CD274 and 33D1. Importantly, baicalin could alleviate embryo resorption of RSA mice by reversing conventional DCs to plasmacytoid DCs and functional molecule expression via inhibiting the STAT5-ID2 pathway. Our research further proved that DCs play an important role in the pathogenesis of RSA and baicalin might be used for treating RSA.

miR-146b-5p and miR-520h Expressions Are Upregulated in Serum of Women with Recurrent Spontaneous Abortion

Unexplained recurrent spontaneous abortion (URSA) is characterized by two or more consecutive pregnancy losses before the 20th week of gestation with unknown etiology. Dysregulation of microRNAs (miRNAs) expression has been reported in reproductive diseases. This study aimed to compare differentially expressed miRNAs in the serum samples between URSA patients and healthy individuals. URSA cases were confirmed by a gynecologist. Peripheral blood sample was‏ gathered from 9 URSA patients, 15 normal pregnant, and 10 non-pregnant women without abortion history. After separating serum, the expression levels of the miR-101-3p, miR-517c-3p, miR-146b-5p, miR-221-3p, and miR-520 h were measured by qRT-PCR assay. The circulating level of miR-520 h in URSA patients was significantly up-regulated compared with healthy pregnant (P < 0.01) and healthy non-pregnant (P = 0.002) women. Furthermore, miR-520 h expression was significantly different between healthy non-pregnant and pregnant women (P = 0.002). Statistical analysis indicated miR-146b-5p expression was significantly up-regulated in URSA patients compared to normal pregnant women (P = 0.018). However, the transcription level of miR-146b-5p was insignificantly different between normal non-pregnant women and the other two groups. Also, circulating levels of miR-101-3p, miR-221-3p, and miR-517c-3p were not significantly different in the studied groups. Statistical analysis showed significant correlations between both miR-221-3p and miR-517c-3p and other miRNAs (P < 0.05). The circulating levels of miR-520 h and miR-146b-5p could be considered biomarkers for URSA diagnosis. Also, miR-517c-3p and miR-221-3p might play a regulatory role in other miRNAs expressions during pregnancy. Previous work, in contrary to our findings, claims that the expression levels of miR-221-3p, miR-101-3p, and miR-517c-3p increased in plasma and tissue samples of patients with URSA. However, our research for the first time indicates that the expression level of miR-520 h and miR-146b-5p in the serum of these patients has increased. Future investigations are necessary to confirm these findings.

Manipulating CD4+ T Cell Pathways to Prevent Preeclampsia

Preeclampsia (PreE) is a placental disorder characterized by hypertension (HTN), proteinuria, and oxidative stress. Individuals with PreE and their children are at an increased risk of serious short- and long-term complications, such as cardiovascular disease, end-organ failure, HTN, neurodevelopmental disorders, and more. Currently, delivery is the only cure for PreE, which remains a leading cause of morbidity and mortality among pregnant individuals and neonates. There is evidence that an imbalance favoring a pro-inflammatory CD4+ T cell milieu is associated with the inadequate spiral artery remodeling and subsequent oxidative stress that prime PreE's clinical symptoms. Immunomodulatory therapies targeting CD4+ T cell mechanisms have been investigated for other immune-mediated inflammatory diseases, and the application of these prevention tactics to PreE is promising, as we review here. These immunomodulatory therapies may, among other things, decrease tumor necrosis factor alpha (TNF-α), cytolytic natural killer cells, reduce pro-inflammatory cytokine production [e.g. interleukin (IL)-17 and IL-6], stimulate regulatory T cells (Tregs), inhibit type 1 and 17 T helper cells, prevent inappropriate dendritic cell maturation, and induce anti-inflammatory cytokine action [e.g. IL-10, Interferon gamma (IFN-γ)]. We review therapies including neutralizing monoclonal antibodies against TNF-α, IL-17, IL-6, and CD28; statins; 17-hydroxyprogesterone caproate, a synthetic hormone; adoptive exogenous Treg therapy; and endothelin-1 pathway inhibitors. Rebalancing the maternal inflammatory milieu may allow for proper spiral artery invasion, placentation, and maternal tolerance of foreign fetal/paternal antigens, thereby combatting early PreE pathogenesis.

Alterations of Cytokine Profiles in Patients With Recurrent Implantation Failure

Serum cytokine profile and T helper (Th)1/Th2 cell balance are related to the success of embryo implantation, although not yet firmly linked to recurrent implantation failure (RIF), a repeated failure to achieve clinical pregnancy following multiple high-quality embryo transfer. In this prospective study, comprehensive bioinfomatic analysis and logistic regression analysis were used to compare the serum cytokine profiles of 41 RIF patients with those of 29 subjects with first-cycle successful pregnancy in the mid-luteal phase and to assess the alterations of cytokine profiles in patients with clinical pregnancy at five weeks post-transplantation. We found several elevated pro-inflammatory cytokines, decreased anti-inflammatory cytokines, and increased Th1/Th2 cytokine ratios in RIF patients compared to control subjects. Specifically, the receiver operating characteristic (ROC) curve generated using multiple indicators provides a high predictive value for diagnosing RIF (area under the curve [AUC] = 0.94, 95% confidence interval [CI] 0.87-1.00, P < 0.0001), with a sensitivity of 96.55% and a specificity of 87.50%. Meanwhile, at five weeks post-transplantation, patients in both groups diagnosed with clinical pregnancy exhibited increased levels of several cytokines compared with pre-pregnancy levels, and a gradual shift in Th1/Th2 balance toward Th2. These findings suggest that inflammatory serum cytokines and the predominance of Th1 cells likely contribute to RIF and possibly reflect the immune environment at the maternal-fetal interface, suggesting their value as outcome indicators in assisted reproductive therapy.

Th17/Regulatory T cells ratio evolution: A prospective study in a group of healthy pregnant women

During pregnancy, the maternal immune system is challenged to tolerate a semi-allogenic fetus. A shift toward a tolerogenic profile is essential to ensure a healthy fetal and placental development. One of the most important mechanisms involved in the maternal immune tolerance towards the fetal antigens is expressed in the activity of the regulatory T (Treg) and Th17 cells. The behavior and equilibrium of these two T lymphocyte populations were rarely studied in normal healthy pregnancies through the beginning of gestation to the postpartum period. We conducted a prospective longitudinal observational study where peripheral blood lymphocyte subsets were analyzed in each trimester of pregnancy and postpartum period in a group of healthy pregnant women. Our study observed a consistent reduction in peripheric Treg cell count through all pregnancy while the Th17 cell count remained stable. The Th17/Treg ratio increases significantly throughout pregnancy to the postpartum period. These changes could be justified by the migration of the immunotolerant Treg cells to the maternal decidua and lead to the establishment of a systemic pro-inflammatory profile by the end of pregnancy. This data could explain why systemic syndromes like preeclampsia develop in susceptible women during the second half of pregnancy or why many autoimmune disorders flourish in the first weeks postpartum.

The Role of Type I and Type II NKT Cells in Materno-Fetal Immunity

NKT cells represent a small but significant immune cell population as being a part of and bridging innate and adaptive immunity. Their ability to exert strong immune responses via cytotoxicity and cytokine secretion makes them significant immune effectors. Since pregnancy requires unconventional maternal immunity with a tolerogenic phenotype, investigation of the possible role of NKT cells in materno-fetal immune tolerance mechanisms is of particular importance. This review aims to summarize and organize the findings of previous studies in this field. Data and information about NKT cells from mice and humans will be presented, focusing on NKT cells characteristics during normal pregnancy in the periphery and at the materno-fetal interface and their possible involvement in female reproductive failure and pregnancy complications with an immunological background.

Danggui-Yimucao Herb Pair Can Protect Mice From the Immune Imbalance Caused by Medical Abortion and Stabilize the Level of Serum Metabolites

Unintended pregnancy is a situation that every woman may encounter, and medical abortion is the first choice for women, but abortion often brings many sequelae. Angelica sinensis Radix (Danggui) and Leonuri Herba (Yimucao) are widely used in the treatment of gynecological diseases, which can regulate menstrual disorders, amenorrhea, dysmenorrhea, and promote blood circulation and remove blood stasis, but the mechanism for the treatment of abortion is not clear. We determined the ability of Danggui and Yimucao herb pair (DY) to regulate the Th1/Th2 paradigm by detecting the level of progesterone in the serum and the expression of T-bet and GATA-3 in the spleen and uterus. Then, we detected the level of metabolites in the serum and enriched multiple metabolic pathways. The arachidonic acid pathway can directly regulate the differentiation of Th1/Th2 cells. This may be one of the potential mechanisms of DY in the treatment of abortion.

Phenotypic characterization of NKT-like cells and evaluation of specifically related cytokines for the prediction of unexplained recurrent miscarriage

Problem

Immune system dysregulation is a major cause of unexplained recurrent miscarriage (URM). Women with URM need screening for their pregnancy microenvironment and immune regulators, to prevent spontaneous abortion.

Method of study

In this study we evaluated NKT-like cell subsets in peripheral venous blood of women with URM using flow cytometry. The expression levels of specifically related Th1 cytokines (IFN-γ and IL-2), Th2 cytokine (IL-4), and Th17 cytokines (IL-17), were measured using enzyme-linked immunosorbent assay.

Results

The percentage of CD16+CD56+NKT-like (Double Positive NKT-like; DPNKT-like) cell subset, and the levels of IL-2 and IFN-γ were significantly elevated in blood of non-pregnant and pregnant patients with URM compared with the healthy control groups, and these parameters were significantly increased after pregnancy in the same patients with URM. Based on the prevalence of the candidate immunological factors in patients with URM, the prognostic significance of the NKT-like cell subsets, IFN-γ and IL-2 profiles were evaluated as potential predictors of URM. A cut-off point of 2.55% for DPNKT-like cell subset in the blood and cut-off values of 39.5 and 20.5 pg/ml for the levels of IFN-γ and IL-2, respectively could be used for the prediction of the risk of spontaneous abortion. To the best of our knowledge, this is the first study that described the prognostic significance of the aforementioned immunological parameters before and after pregnancy, and highlighted the correlation of NKT-like cells and the candidate Th1 cytokines with pregnancy loss in women with URM.

Conclusions

DPNKT-like cells, IFN-γ and IL-2 patient profiles could be used as markers to predict the risk of miscarriage in patients with URM.

•

Disturbance in the immune system's regulators is an essential factor for recurrent miscarriage.

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There is an urgent need for women who have suffered pregnancy loss to identify specific immune regulators that underline recurrent miscarriage, to prevent and control miscarriage.

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CD16+CD56+NKT-like cells, Interferon-γ and Interleukin-2 patient profile could be utilized as biomarkers to predict risk of miscarriage in women who have suffered spontaneous miscarriage.

DNA Methylation and Recurrent Pregnancy Loss: A Mysterious Compass?

Recurrent pregnancy loss (RPL) is a common and severe pathological pregnancy, whose pathogenesis is not fully understood. With the development of epigenetics, the study of DNA methylation, provides a new perspective on the pathogenesis and therapy of RPL. The abnormal DNA methylation of imprinted genes, placenta-specific genes, immune-related genes and sperm DNA may, directly or indirectly, affect embryo implantation, growth and development, leading to the occurrence of RPL. In addition, the unique immune tolerogenic microenvironment formed at the maternal-fetal interface has an irreplaceable effect on the maintenance of pregnancy. In view of these, changes in the cellular components of the maternal-fetal immune microenvironment and the regulation of DNA methylation have attracted a lot of research interest. This review summarizes the research progress of DNA methylation involved in the occurrence of RPL and the regulation of the maternal-fetal immune microenvironment. The review provides insights into the personalized diagnosis and treatment of RPL.

In vitro fertilization-embryo transfer in patients with unexplained recurrent pregnancy loss

Background:

Empiric therapy for patients with unexplained recurrent pregnancy loss (URPL) is not precise. Some patients will ask for assisted reproductive technology due to secondary infertility or advanced maternal age. The clinical outcomes of URPL patients who have undergone in vitro fertilization-embryo transfer (IVF-ET) require elucidation. The IVF outcome and influencing factors of URPL patients need further study.

Methods:

A retrospective cohort study was designed, and 312 infertile patients with URPL who had been treated during January 2012 to December 2015 in the Reproduction Center of Peking University Third Hospital were included. By comparing clinical outcomes between these patients and those with tubal factor infertility (TFI), the factors affecting the clinical outcomes of URPL patients were analyzed.

Results:

The clinical pregnancy rate (35.18% vs. 34.52% in fresh ET cycles, P = 0.877; 34.48% vs. 40.27% in frozen-thawed ET cycles, P = 0.283) and live birth rate (LBR) in fresh ET cycles (27.67% vs. 26.59%, P = 0.785) were not significantly different between URPL group and TFI group. URPL group had lower LBR in frozen-thawed ET cycles than that of TFI group (23.56% vs. 33.56%, P = 0.047), but the cumulative LBRs (34.69% vs. 38.26%, P = 0.368) were not significantly different between the two groups. The increased endometrial thickness (EMT) on the human chorionic gonadotropin day (odds ratio [OR]: 0.848, 95% confidence interval [CI]: 0.748–0.962, P = 0.010) and the increased number of eggs retrieved (OR: 0.928, 95% CI: 0.887–0.970, P = 0.001) were protective factors for clinical pregnancy in stimulated cycles. The increased number of eggs retrieved (OR: 0.875, 95% CI: 0.846–0.906, P < 0.001), the increased two-pronucleus rate (OR: 0.151, 95% CI: 0.052–0.437, P < 0.001), and increased EMT (OR: 0.876, 95% CI: 0.770–0.997, P = 0.045) in ET day were protective factors for the cumulative live birth outcome.

Conclusion:

After matching ages, no significant differences in clinical outcomes were found between the patients with URPL and the patients with TFI. A thicker endometrium and more retrieved oocytes increase the probability of pregnancy in fresh transfer cycles, but a better normal fertilization potential will increase the possibility of a live birth.

Biology and pathology of the uterine microenvironment and its natural killer cells

Tissues are the new frontier of discoveries in immunology. Cells of the immune system are an integral part of tissue physiology and immunity. Determining how immune cells inhabit, housekeep, and defend gut, lung, brain, liver, uterus, and other organs helps revealing the intimate details of tissue physiology and may offer new therapeutic targets to treat pathologies. The uterine microenvironment modulates the development and function of innate lymphoid cells [ILC, largely represented by natural killer (NK) cells], macrophages, T cells, and dendritic cells. These immune cells, in turn, contribute to tissue homeostasis. Regulated by ovarian hormones, the human uterine mucosa (endometrium) undergoes ~400 monthly cycles of breakdown and regeneration from menarche to menopause, with its fibroblasts, glands, blood vessels, and immune cells remodeling the tissue into the transient decidua. Even more transformative changes occur upon blastocyst implantation. Before the placenta is formed, the endometrial glands feed the embryo by histiotrophic nutrition while the uterine spiral arteries are stripped of their endothelial layer and smooth muscle actin. This arterial remodeling is carried out by invading fetal trophoblast and maternal immune cells, chiefly uterine NK (uNK) cells, which also assist fetal growth. The transformed arteries no longer respond to maternal stimuli and meet the increasing demands of the growing fetus. This review focuses on how the everchanging uterine microenvironment affects uNK cells and how uNK cells regulate homeostasis of the decidua, placenta development, and fetal growth. Determining these pathways will help understand the causes of major pregnancy complications.

Pro- and Anti-Inflammatory Cytokines in the First Trimester-Comparison of Missed Miscarriage and Normal Pregnancy

The advantage in response of Th2 over Th1 is observed in normal pregnancy in peripheral blood. A disturbance of this balance can lead to symptoms of miscarriage and pregnancy loss. The aim of this study was to evaluate the pro- and anti-inflammatory cytokines in sera of women who were diagnosed with missed miscarriage in the first trimester and to compare this systemic immune response to the response in women with normal pregnancy. The study group consisted of 61 patients diagnosed with missed miscarriage. In total, 19 healthy women with uncomplicated first trimester created the control group. Cytokines were determined in the maternal serum by ELISA. The analysis included INF-γ, TNF-α, Il-1β, Il-4, Il-5, Il-6, Il-9, Il-10, Il-13 and TGF-β1. Th1 cytokine levels in the study group reached slightly higher values for INF-γ, Il-1β and slightly lower for IL-6 and TNF-α. In turn, Th2 cytokine levels in the study group were slightly higher (Il-9, Il-13), significantly higher (Il4, p = 0.015; Il-5, p = 0.0003) or showed no differences with the control group (Il-10). Slightly lower concentration involved only TGF-β1. Analysis of the correlation between levels of pro- and anti-inflammatory cytokines resulted in some discrepancies, without showing predominance of a specific immune response. The results did not confirm that women with missed miscarriage had an advantage in any type of immune response in comparison to women with normal pregnancy.

Association of gastrointestinal parasite burden, serum cytokines and hormones concentrations, and pregnancy in Angus-cross beef cows

The objective was to elucidate the relationships among gastrointestinal (GI) parasite load, serum cytokines (Th 1 - Interleukin (IL) 2, Interferon (IFN) γ and Tumor necrosis factor (TNF) α; Th 2- IL4, IL6, and IL10) levels, hormones (progesterone, cortisol, 8-epi-prostaglandin F2 alpha (isoprostane), prolactin, substance-p, and prostaglandin F metabolites) concentrations, and pregnancy in beef cattle. Angus-cross beef cows (n = 700; age, 3-8 y) were blocked by age and body condition score (BCS, 1-9), and were randomly assigned to treatment (n = 350, TRT, 50 mg of eprinomectin/50 kg BW, im) or control (n = 350, CON, no treatment) on Day -30. Cows were synchronized using Controlled Internal Drug Release insert (CIDR) + CO-Synch protocol and artificially inseminated at a fixed time on Day 0 (66 h after CIDR removal). Fecal samples were collected to determine fecal egg count per gram (FEG, McMaster method) on Days -30, -23, -16, -7, 7, 0, 16 and 23, and blood samples were collected on Days -7, 0, 7, 16 and 23. Serum cytokines were determined on Days -7, 0, 7, 16 and 23, and circulating hormones were measured on Day 16. BCS were recorded on Day 16 following artificial insemination (AI), and pregnancy status was diagnosed on Day 30 and 60. Pregnancy/AI varied among treatment groups on Day 30 [TRT, 62.0% (217/350); CON, 54.9% (192/350) (P = 0.05)] and Day 60 [TRT, 60.9% (213/350); CON, 51.7% (181/350) (P < 0.05)]. Pregnancy loss between 30 and 60 days for TRT and CON groups were 1.8% (4/217) and 5.7% (11/192), respectively (P < 0.05). The BCS on Day 16 did not differ among treatment groups (P> 0.1). Four groups of 40 cows were selected based on their pregnancy status and treatment: pregnant, TRT; non-pregnant, TRT; pregnant, CON; and non-pregnant, CON to compare the mean FEG, cytokines, and hormones levels. The FEG and cytokine concentrations were significantly (P < 0.05) influenced by treatment, pregnancy status, day, treatment by pregnancy status, and treatment by day. Day 16 hormone concentrations were considerably influenced by treatment, pregnancy status, and treatment by pregnancy. Although FEG on Day -30 did not differ among the groups (P> 0.1), it was lower in treated, pregnant cows compared with cows in other three groups from Day -23 onwards (P < 0.05). Overall and pairwise comparisons showed that serum concentrations of Type 1 cytokines, IL2, IFNγ, and TNFα were lower (P < 0.05) from gestational Day 7 onwards in treated, pregnant cows compared with cows in other three groups. In contrast, serum concentrations of Type 2 cytokines, IL4, IL6 and IL10 were greater (P < 0.05) from gestational Day 7 onwards in treated, pregnant cows compared with cows in other groups. Serum concentrations of progesterone was greater and other hormones were lower for pregnant cows in TRT group compared to cows in other groups on gestational Day 16. In conclusion, GI parasite load was reduced; Th 1 cytokines levels were decreased; Th 2 cytokines concentrations were increased; progesterone level was increased; and cortisol, substance-P, prolactin, isoprostane, and PGFM were decreased in pregnant, TRT cows. These changes also resulted in an increase in P/AI. It is plausible that direct and bidirectional host-parasite interactions mediated by cytokines and hormones may have promoted maternal tolerance of an immunologically diverse conceptus and the establishment of pregnancy.

The Effects of LIT and MLR-Bf on Immune Biomarkers and Pregnancy Outcomes in Women With Previous Early Recurrent Miscarriage: A Retrospective Study

Background: Immunological failure during pregnancy is considered one of the etiologies of recurrent miscarriage (RM). The decreased production of mixed lymphocyte reaction-blocking factors (MLR-Bf) may play a major role in this condition. Lymphocyte immunotherapy (LIT), which induces the production of MLR-Bf, has been used in treating RM patients since 1984. However, the effectiveness of LIT is currently being heatedly debated. In addition to that, possible changes to the maternal immune system upon induced MLR-Bf production by LIT remains unclear. Objectives: To explore the possible impacts that MLR-Bf may have on the expression of immune biomarkers and pregnancy outcomes, and deduce whether the prevention of miscarriages is possible with LIT or MLR-Bf in RM patients. Materials and Methods: Women with previous early RM (eRM) were enrolled in this retrospective study after they got pregnant again. LIT was implemented before pregnancy and during the first trimester. MLR-Bf and immune biomarkers were checked as the clinical routine. Patients were followed up until 12 gestational weeks. Levels of immune biomarkers and successful pregnancy rates were compared between MLR-Bf^- group and MLR-Bf⁺ group stratified by LIT. Independent associations between LIT, or MLR-Bf, and miscarriage were estimated. All data management and analysis were conducted using SPSS 20.0. Results: A total of 1,038 patients, 497 MLR-Bf^- (49 cases accepted LIT), and 541 MLR-Bf⁺(463 cases induced by LIT) were included in the study. Percentage of lymphocytes, the ratio of CD4+ T cells/lymphocytes, and levels of some rheumatoid biomarkers (anti-U1-nRNP, anti-SAA-52kd, and anti-CENOP B) were statistically higher in MLR-Bf⁺ group than in MLR-Bf^- group among women without LIT. With LIT treatment the successful pregnancy rate was statistically higher in MLR-Bf⁺ group than in MLR-Bf^- group (66.7% vs. 51.0%, P = 0.028) among women with LIT. Meanwhile, LIT was estimated to have an independent negative association with miscarriage. Conclusion: Upon LIT treament levels of immune biomarkers were different in women with and without MLR-Bf when stratified by whether they received LIT. Not MLR-Bf, but LIT, has an independent protective effect on miscarriage.

Relationship Between Pregnancy and Acute Disseminated Encephalomyelitis: A Single-Case Study

The relationship between pregnancy and autoimmune diseases is unclear. This study investigated the possible role of local immune changes and the activation state of the HMGB1/TLR4/Nf-κB/IL-6 pathway at the maternal–fetal interface during pregnancy in the pathogenesis of acute disseminated encephalomyelitis (ADEM). Clinical data and blood samples of a patient with ADEM were collected to observe the dynamic changes in lymphocyte populations after an abortion. The expression of HMGB1, TLR4, Nf-κB, AQP4, IL-2, IL-4, IL-6, and TNF-α in the fetal membrane and placenta was compared between the patient with pregnancy-related ADEM and a woman with a normal pregnancy using Real-time qPCR and western blotting (WB). The patient was diagnosed with ADEM in the early stage of pregnancy after showing limb weakness symptoms. In the third month of gestation, the symptoms worsened, with a disturbance of consciousness and breathing. After the abortion, the patient relapsed with vertigo and visual rotation. Analysis of lymphocyte subsets by flow cytometry showed that B lymphocytes increased, while natural killer T lymphocytes decreased. WB and Real-time qPCR showed that the expression levels of HMGB1, TLR4, Nf-κB, AQP4, and IL-6 in the fetal membrane and placenta were higher in the patient with pregnancy-related ADEM than in the woman with a normal pregnancy, while those of IL-2 were lower in the patient than in the woman with a normal pregnancy. The local immune changes and the activation of the HMGB1/TLR4/Nf-κB/IL-6 pathway at the maternal–fetal interface may be related to the pathogenesis of ADEM.

Sinomenine Improves Embryo Survival by Regulating Th1/Th2 Balance in a Mouse Model of Recurrent Spontaneous Abortion

Background

This study aims to explore the effect of Sinomenine (SIN) on pregnancy outcomes of recurrent spontaneous abortion (RSA) in a mouse model.

Material/Methods

Thirty female CBA/J mice were allocated into 3 groups randomly, then mated with BALB/c mice (CBA/J×BALB/c) as normal-pregnancy group (n=10), or mated with DBA/2 mice (CBA/J×DBA/2) as RSA model (n=10), or CBA/J×DBA/2 mice treated with SIN as RSA+SIN group (n=10). The number of surviving and reabsorbed embryos in each group were counted on day 13.5 of gestation. The mouse serum was collected to determine the levels of interferon-γ (IFN)-γ and IL-4 by ELISA. Immunohistochemistry, qRT-PCR and immunoblotting were used to determine the location, mRNA and protein expressions of IFN-γ, IL-4, T-bet and GATA3 in the decidual and placental tissue.

Results

In the RSA group, the amount of reabsorbed embryo was significantly higher than that in the normal-pregnancy group. However, SIN treatment showed a rescue effect on spontaneous abortion in RSA mice. IFN-γ, IL-4, T-bet, and GATA3 were all expressed in placental tissues and mainly located in the cytoplasm. The RSA group demonstrated higher expression levels of IFN-γ and T-bet than in the RSA+SIN and normal-pregnancy groups. Although RSA and RSA+SIN groups showed lower expression levels of IL-4 and GATA3 than in the normal-pregnancy group, there was no significant difference between RSA and RSA+SIN groups regarding IL-4 and GATA expression levels.

Conclusions

SIN treatment demonstrates a therapeutic effect on spontaneous abortion in RSA mice, possibly through regulating the balance of Th1/Th2 in maternal circulation and decidual tissues.

Recent insights into the impact of immune dysfunction on reproduction in autoimmune thyroiditis

Autoimmune thyroiditis (AIT) is a common organ-specific autoimmune disease with a high incidence among women of childbearing age. Recent studies have reported that women with AIT are more susceptible to infertility, miscarriage and preterm birth. It has been investigated that abnormal changes in maternal immune system and maternal-fetal interface can dampen the immune tolerance between mother and fetus, which underlie the pathogenesis of adverse pregnancy outcomes. Hence, we summarize the immunological changes related to adverse reproductive outcomes in AIT and highlight the respective contributions of both humoral and cellular immune dysfunctions to pregnancy failures. Moreover, the direct impacts of AIT on maternal-fetal immune activation and biological influences to trophoblasts are discussed as well. All these associations require confirmation in larger studies, and the pathogenic mechanisms need to be better understood, which might provide useful information for clinical diagnosis and therapy of AIT.

Definition and Multiple Factors of Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) is usually defined as three or more spontaneous abortions prior to 20-28 weeks gestation. RSA affects approximately 2-5% of all women of childbearing age, and it brings tremendous psychological and psychiatric trauma to the women and also results in economic burden. The causes could be female age, anatomical and chromosomal abnormalities, genetic, endocrinological, placental anomalies, infection, smoking and alcohol consumption, psychological factor, exposure to environmental factors such as heavy metal, environment pollution, and radiation.

Cytokine imbalance at materno-embryonic interface as a potential immune mechanism for recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a prominent reproductive disease that distresses about 2%-5% of couples. RPL is the loss of two or more successive spontaneous pregnancies prior to the 20th week of embryo development. The commencement of pregnancy necessitates implantation of the embryo into responsive maternal decidua synchronized with the process of placentation, decidual and myometrial trophoblast incursion as well as refashioning of spiral blood arteries of uterus. The collapse of any of the processes fundamental for pregnancy success may result into an array of pregnancy problems including spontaneous pregnancy loss. Endometrium of human female manufactures an extensive range of cytokines during the proliferative and secretory stage of the menstrual cycle. These endometrial cytokines are thought as major players for making the uterus ready for embryo implantation and placental development during pregnancy. Decidual cytokines regulate the invasion of trophoblast and remodeling of spiral arteries as well as take part in immune suppression to accomplish the pregnancy. Deterrence of maternal rejection of embryo needs a regulated milieu, which takes place essentially at the embryo-maternal interface and the tissues of the uterus. The reasons of RPL remain anonymous in a large number of cases that lead to difficulties in management and severe trauma in couples. Cytokine modulatory therapies have been shown promising for preventing RPL. Further study of novel factors is wanted to establish more effective RPL treatment protocols. The present study aims to review the outcome of cytokine breach at materno-embryonic interface and the efficacy of cytokine modulatory therapies in RPL.

Visualizing Dynamic Changes at the Maternal-Fetal Interface Throughout Human Pregnancy by Mass Cytometry

During healthy pregnancy, a balanced microenvironment at the maternal-fetal interface with coordinated interaction between various immune cells is necessary to maintain immunological tolerance. While specific decidual immune cell subsets have been investigated, a system-wide unbiased approach is lacking. Here, mass cytometry was applied for data-driven, in-depth immune profiling of the total leukocyte population isolated from first, second, and third trimester decidua, as well as maternal peripheral blood at time of delivery. The maternal-fetal interface showed a unique composition of immune cells, different from peripheral blood, with significant differences between early and term pregnancy samples. Profiling revealed substantial heterogeneity in the decidual lymphoid and myeloid cell lineages that shape gestational-specific immune networks and putative differentiation trajectories over time during gestation. Uncovering the overall complexity at the maternal-fetal interface throughout pregnancy resulted in a human atlas that may serve as a foundation upon which comprehension of the immune microenvironment and alterations thereof in pregnancy complications can be built.

miR-146a-5p improves the decidual cytokine microenvironment by regulating the toll-like receptor signaling pathway in unexplained spontaneous abortion

Spontaneous abortion (SA) is a common pregnancy failure, but the cause of numerous cases remains unexplained. Decidual immune cells (DICs)-mediated cytokine microenvironment is involved in pregnancy and regulated by many microRNAs, but whether microRNA-146a-5p (miR-146a) regulate the decidual cytokine microenvironment and the potential mechanisms in unexplained SA pathogenesis have rarely been reported. In this study, the levels of cytokines and miR-146a in healthy and unexplained SA deciduae were first investigated, and the correlation between them was analyzed. Then, the effect of miR-146a inhibitor on cytokines was assessed in healthy deciduae-derived DICs. Third, the downstream targets and related molecular mechanisms of miR-146a were analyzed by bioinformatics, and the levels of the predicted targets in deciduae were assessed, followed by the correlation analysis between the levels of miR-146a and the targets. Finally, the effect of miR-146a on the predicted targets and inflammatory cytokines was validated in unexplained SA deciduae-derived DICs. As a result, decreased miR-146a correlated with the cytokine disorder in unexplained SA deciduae, and inhibition of miR-146a promoted pro-inflammatory response in healthy deciduae-derived DICs. One hundred four target genes and related molecular mechanisms of miR-146a were predicted, among which the toll-like receptor (TLR) pathway might be associated with the decidual cytokine regulation. Upregulation of miR-146a inhibited the expression of the predicted molecules enriched in the TLR pathway and improved the cytokine disorder in unexplained SA deciduae-derived DICs. Collectively, miR-146a improves the decidual cytokine microenvironment by regulating the TLR pathway in unexplained SA, providing novel potential targets for further therapeutic research.

The role of maternal-foetal interface inflammation mediated by NLRP3 inflammasome in the pathogenesis of recurrent spontaneous abortion

INTRODUCTION

Approximately half of the recurrent spontaneous abortions (RSAs) that remain unidentified to date may be closely related to inflammation. Our previous study found excessive NLRP3 inflammasomes in RSA patients. Here, we investigated further the role of inflammasomes in the maternal-foetal interface of RSA patients.

METHODS

Villous and decidual tissues were collected during uterine curettage. The trophoblast cell line TEV-1 was cultured with lipopolysaccharide (LPS) or low molecular weight heparin (LMWH), and then the macrophage cell line RAW264.7 was treated with trophoblast media. The expression and localisation of inflammasomes in tissues and cells were detected, and the migration and proliferation of cells were analysed.

RESULTS

A significantly increased expression of inflammasomes was observed in RSA tissues compared with those in the normal group, and it was more obvious in villous tissues than in decidual tissues. In TEV-1 cells, after LPS stimulation, the expression of inflammasomes was increased, but the cell activity was decreased, whereas in RAW264.7, both expression of inflammasomes and cell activity were increased in the LPS group. In addition, LMWH could inhibit the action of LPS in above cells.

DISCUSSION

In patients experiencing RSA, abnormal inflammatory response might be mediated by NLRP3 inflammasomes on the maternal-foetal interface, which may reduce trophoblast activity and promote macrophage activity, leading to early embryo implantation failure. LMWH is expected to treat RSA patients by blocking this process.

Expression of trophoblast derived prostaglandin E2 receptor 2 (EP2) is reduced in patients with recurrent miscarriage and EP2 regulates cell proliferation and expression of inflammatory cytokines

BACKGROUD

Prostaglandin E2 (PGE2), an inflammatory mediator, modulates cytokines, regulates immune responses in reproductive processes and stimulates inflammatory reactions via the prostaglandin E2 receptor 2 (EP2). However, the regulatory effects of EP2 signaling on trophoblasts and its role in unexplained recurrent miscarriage (uRM) remains unclear.

PATIENTS AND METHODS

A total of 19 placentas from patients with a history of more than two consecutive pregnancy losses of unknown cause (uRM group) and placentas of 19 healthy patients following a legal termination of their pregnancy were used for PGE2 receptor (EP1, EP2 and EP4) expression analyses via immunohistochemistry. Double immunofluorescence was also used to identify EP2 expressing cells in the decidua. Finally, HTR-8/SVneo cells were used to clarify the role of EP2 in in vitro experiments.

RESULTS

The expression of EP2 and EP4 was found to be reduced in the syncytiotrophoblast and decidua of uRM patients. A selective EP2 receptor antagonist (PF-04,418,948) reduced the proliferation and secretion of ß-hCG, inhibited interleukin -6 (IL-6) and interleukin-8 (IL-8) and up-regulated the production of the tumor necrosis factor-α (TNF-α) and plasminogen activator inhibitor type 1 (PAI-1) in HTR-8/SVneo cells in vitro.

CONCLUSION

PGE2-EP2 signaling pathway may represent a novel therapy option for uRM. The involvement of EP2 in uRM acts perhaps via inflammatory cytokines and indicates that the PGE2-EP2 signaling pathway might represent an unexplored etiology for uRM.

Got your mother in a whirl: The role of maternal T cells and myeloid cells in pregnancy

Appropriate development of the placenta is required for healthy pregnancy to occur. After implantation of the fertilized blastocyst, fetal trophoblasts invade the endometrium and myometrium of the mother's uterus to establish placentation. In this process, fetal trophoblasts encounter maternal immune cells. In this review, we focus on the role of maternal T cells and myeloid cells (macrophages, dendritic cells) in pregnancy and their interaction with trophoblasts. To retain immunologic tolerization, trophoblasts evade immune recognition by T cells and produce factors that modulate their phenotype and function. On top of that, the local environment at the maternal-fetal interface favors expansion of regulatory T cells. Macrophages and dendritic cells are essential in maintaining a healthy pregnancy. They produce soluble factors and act as antigen-presenting cells, thereby interacting with T cells. Herein, M2 macrophages, immature dendritic cells, CD4⁺ Th2 cells, and regulatory T cells represent an axis that maintains a local immune tolerant environment. We consider outstanding issues concerning these cell types and their pathways, which need to be addressed in future investigations. Data from recent single-cell sequencing experiments of the placental bed, to study heterogeneity of maternal immune cells and to predict cell-cell interactions, are discussed. Novel ways for long-term culturing of primary trophoblasts allow for cell-cell interaction studies in a functional way. Future directions should include study of the functionality of currently known and newly identified decidual immune cell subsets in healthy and complicated pregnancies, and their interaction with and modulation by trophoblast cells.

The expression of intracellular cytokines of decidual natural killer cells in unexplained recurrent pregnancy loss

OBJECTIVE

This study aims to investigate the expression levels of TNF-α, IFN-γ, IL-4, and IL-10 in dNK cells and determine whether or not the MAPK signal pathway is involved in the regulation of cytokine secretion by dNK cells at the maternal-fetal interface.

METHODS

In this study, we collected decidua specimens from patients with apparently normal pregnant and unexplained recurrent pregnancy loss (URPL) and extracted dNK cells by enzymatic digestion. Then the expression of cytokines were analyzed by flow cytometry and Real-Time PCR respectively.

RESULTS

The secretions of both IFN-γ and TNF-α in dNK cells in URPL were significantly higher than those in normal pregnancy. Furthermore, p38/MAPK inhibitors can inhibit the secretion of four cytokines in normal pregnancy, while in URPL cases, p38/MAPK inhibitors only significantly inhibit the secretion of IL-4 and IFN-γ. ERK inhibitors had no effect on the expression of all four cytokines and JNK/MAPK inhibitors varied on different cytokines.

CONCLUSION

URPL is associated with a NK1 cytokine profile. MAPK signaling pathway is involved in the regulation of cytokine secretion by decidual NK cells at maternal-fetal interface.

Functional significance of lymphocytes in pregnancy and lymphocyte immunotherapy in infertility: A comprehensive review and update

During pregnancy, the fetal-maternal interface underlies several dynamic alterations to permit the fetus to be cultivated and developed in the uterus, in spite of being identifies by the maternal immune system. A large variety of decidual leukocyte populations, including natural killer cells, NKT cells, innate lymphoid cells, dendritic cells, B cells, T cells, subpopulations of helper T cells play a vital role in controlling the trophoblast invasion, angiogenesis as well as vascular remodeling. In contrast, several regulatory immunosuppressive mechanisms, including regulatory T cells, regulatory B cells, several cytokines and mediators are involved in maintain the homeostasis of immune system in the fetal-maternal interface. Nonetheless, aberrant alterations in the balance of immune inflammatory or immunosuppressive arms have been associated with various pregnancy losses and infertilities. As a result, numerous strategies have been developed to revers dysregulated balance of immune players to increase the chance of successful pregnancy. Lymphocyte immunotherapy has been developed through utilization of peripheral white blood cells of the husband or others and administered into the mother to confer an immune tolerance for embryo's antigens. However, the results have not always been promising, implying to further investigations to improve the approach. This review attempts to clarify the involvement of lymphocytes in contributing to the pregnancy outcome and the potential of lymphocyte immunotherapy in treatment of infertilities with dysregulated immune system basis.

Physiological and pathological regulation of autophagy in pregnancy

Autophagy exists widely in eukaryotic cells and is regulated by a variety of molecular mechanisms. Its physiological functions include providing energy, maintaining cell homeostasis, and promoting apoptosis of abnormal cells. At present, the regulation of autophagy in tumor, degenerative disease, and cardiovascular disease has attracted much attention. Gradually, the role of autophagy in pregnancy tends to be valued. The previous literature has shown that autophagy can influence the occurrence and maintenance of pregnancy from three aspects: embryo (affecting the process of fertilization and embryonic development and the function of trophoblast cells), maternal (decidualization), and maternal-to-fetal immune crosstalk. Undoubtedly, abnormalities in autophagy levels are associated with a variety of pregnancy complications, such as preeclampsia, fetal growth restriction, and preterm delivery which have been proven by human, animal, and in vitro experiments. The regulation of autophagy is expected to be a target for the treatment of these pregnancy complications. This article reviews the research on autophagy, especially about its physiological and pathological regulation during pregnancy.

Maternal Obesity and the Uterine Immune Cell Landscape: The Shaping Role of Inflammation

Inflammation is often equated to the physiological response to injury or infection. Inflammatory responses defined by cytokine storms control cellular mechanisms that can either resolve quickly (i.e., acute inflammation) or remain prolonged and unabated (i.e., chronic inflammation). Perhaps less well-appreciated is the importance of inflammatory processes central to healthy pregnancy, including implantation, early stages of placentation, and parturition. Pregnancy juxtaposed with disease can lead to the perpetuation of aberrant inflammation that likely contributes to or potentiates maternal morbidity and poor fetal outcome. Maternal obesity, a prevalent condition within women of reproductive age, associates with increased risk of developing multiple pregnancy disorders. Importantly, chronic low-grade inflammation is thought to underlie the development of obesity-related obstetric and perinatal complications. While diverse subsets of uterine immune cells play central roles in initiating and maintaining healthy pregnancy, uterine leukocyte dysfunction as a result of maternal obesity may underpin the development of pregnancy disorders. In this review we discuss the current knowledge related to the impact of maternal obesity and obesity-associated inflammation on uterine immune cell function, utero-placental establishment, and pregnancy health.

The Role of Analysis of NK Cell Subsets in Peripheral Blood and Uterine Lavage Samples in Evaluation of Patients with Recurrent Implantation Failure

OBJECTIVE

In this study, we aimed to determine the role of analyses of NK cell subsets in peripheral blood and uterine lavage samples in evaluation of patients with unexplained RIF.

METHODS

This retrospective single-institution case-control study included two different cohorts between 2017-2019. First cohort included patients examined with peripheral blood samples for evaluation of possible immunologic problems in patients with unexplained recurrent implantation failure; in the study period, a total of 75 consecutive patients with RIF (study group; n: 42) or infertile patients without RIF (control group; n: 33) were included. Second cohort included those patients whose uterine samples were assessed for immunologic problems; RIF (study group ; n: 16) or infertile patients without RIF (control group; n: 25).

RESULTS

In the first cohort, the percentage of NK cells (CD3-CD16⁺56⁺) is statistically significantly lower (9.8 vs. 12.6, respectively, p: 0.038) in the study group than those of the controls whereas there was no statistical significance in the absolute number of NK cells (CD3-CD16⁺56⁺). In the second cohort, the only remarkable finding in uterine lavage samples was significantly increased uNKs cells (CD3-CD16^dim56^bright) percentages in controls (9.95 vs 12.7, respectively, p: 0.026) compared to those of study group.

CONCLUSION

Our data shows that the analysis of NK cell subtypes in peripheral blood does not seem appropriate to investigate the patients with RIF and we suggest that uterine lavage samples instead of peripheral blood samples be implemented and evaluated.

Vitamin D Effects on the Immune System from Periconception through Pregnancy

Vitamin D is a well-known secosteroid and guardian of bone health and calcium homeostasis. Studies on its role in immunomodulatory functions have expanded its field in recent years. In addition to its impact on human physiology, vitamin D influences the differentiation and proliferation of immune system modulators, interleukin expression and antimicrobial responses. Furthermore, it has been shown that vitamin D is synthesized in female reproductive tissues and, by modulating the immune system, affects the periconception period and reproductive outcomes. B cells, T cells, macrophages and dendritic cells can all synthesize active vitamin D and are involved in processes which occur from fertilization, implantation and maintenance of pregnancy. Components of vitamin D synthesis are expressed in the ovary, decidua, endometrium and placenta. An inadequate vitamin D level has been associated with recurrent implantation failure and pregnancy loss and is associated with pregnancy-related disorders like preeclampsia. This paper reviews the most important data on immunomodulatory vitamin D effects in relation to the immune system from periconception to pregnancy and provides an insight into the possible consequences of vitamin D deficiency before and during pregnancy.

Noncoding RNAs in Unexplained Recurrent Spontaneous Abortions and Their Diagnostic Potential

Unexplained recurrent spontaneous abortion (URSA) is defined as the loss of two or more consecutive pregnancies before the 20th week of gestation with normal findings on routine screening tests. Our understanding of the cellular and molecular pathogenesis of URSA is still far from complete. Noncoding RNAs (ncRNAs) play a pivotal role in transcription and expression. The functions of ncRNAs may also improve understanding of URSA pathogenesis. Because of their stability in the circulatory system and at the maternal-fetal interface, it may be possible to use ncRNAs as biomarkers for certain disease states. Here, we provide a narrative review of the current state of knowledge about ncRNAs associated with URSA. The possibility of developing a diagnostic tool using ncRNAs is discussed. The underlying mechanisms of how ncRNAs may lead to the onset of URSA are explored in this review.