Causal Relationship Between Circulating Immune Cells and Recurrent Spontaneous Abortion: A Bidirectional Mendelian Randomization Study.

BACKGROUND: Recurrent spontaneous abortion (RSA) is a serious and common complication of pregnancy caused by multiple factors. The etiology remains incompletely understood, but immunologic factors play important roles. Here, we aimed to evaluate whether circulating immune cells causally impacted RSA. METHODS: In this study, we conducted a comprehensive two-sample Mendelian randomization (MR) study to determine the causal association between the 731 immunophenotypes of human peripheral blood lymphocytes and the number of spontaneous abortions as well as recurrent miscarriage. Sensitivity analyses were performed to assess and minimize heterogeneity and horizontal pleiotropy. Reverse MR analysis was used to assess reverse causality. RESULTS: After Bonferroni-correction, eight immunophenotypes were significantly associated with the number of spontaneous abortions: FSC-A on CD4+ T cell (beta = -0.051, 95% CI = [-0.085, -0.017], P-value = 0.004), CD8 on HLA DR+ CD8+ T cell (beta = -0.040, 95% CI = [-0.067, -0.014], P-value = 0.003), HLA DR on CD33dim HLA DR+ CD11b- (beta = -0.021, 95% CI = [-0.036, -0.005], P-value = 0.010), HLA DR+ T cell Absolute Count (beta = 0.022, 95% CI = [0.006, 0.037], P-value = 0.008), HLA DR+ T cell % lymphocyte (beta = 0.026, 95% CI = [0.010, 0.041], P-value = 0.001), HLA DR+ T cell % T cell (beta = 0.023, 95% CI = [0.007, 0.039], P-value = 0.004), HLA DR+ CD4+ T cell % lymphocyte (beta = 0.034, 95% CI = [0.007, 0.060], P-value = 0.012), and HLA DR on B cell (beta = 0.012, 95% CI = [0.003, 0.021], P-value = 0.010). In addition, we identified two immunophenotypes associated with recurrent miscarriage: HLA DR on B cell (OR = 0.854, 95% CI = [0.757, 0.964], P-value = 0.011), and CD19 on naive-mature B cell (OR = 4.595, 95% CI = [1.674, 12.617], P-value = 0.003). There was no evidence of heterogeneity, horizontal pleiotropy and reverse causality. CONCLUSIONS: Our study demonstrated a tight link between adaptive immune cells and RSA through genetic means, thus providing potential therapeutic targets or novel diagnostic biomarkers.

Maternal-fetal immunity and recurrent spontaneous abortion.

Recurrent Spontaneous Abortion (RSA) is a common pregnancy complication, that has multifactorial causes, and currently, 40%-50% of cases remain unexplained, referred to as Unexplained RSA (URSA). Due to the elusive etiology and mechanisms, clinical management is exceedingly challenging. In recent years, with the progress in reproductive immunology, a growing body of evidence suggests a relationship between URSA and maternal-fetal immunology, offering hope for the development of tailored treatment strategies. This article provides an immunological perspective on the pathogenesis, diagnosis, and treatment of RSA. On one hand, it comprehensively reviews the immunological mechanisms underlying RSA, including abnormalities in maternal-fetal interface immune tolerance, maternal-fetal interface immune cell function, gut microbiota-mediated immune dysregulation, and vaginal microbiota-mediated immune anomalies. On the other hand, it presents the diagnosis and existing treatment modalities for RSA. This article offers a clear knowledge framework for understanding RSA from an immunological standpoint. In conclusion, while the "layers of the veil" regarding immunological factors in RSA are gradually being unveiled, our current research may only scratch the surface. In terms of immunological etiology, effective diagnostic tools for RSA are currently lacking, and the efficacy and safety of immunotherapies, primarily based on lymphocyte immunotherapy and intravenous immunoglobulin, remain contentious.

The microbiome in recurrent pregnancy loss - A scoping review.

Recurrent pregnancy loss (RPL) is a troubling condition that affects couples worldwide. Despite extensive research efforts, many RPL cases remain unexplained, highlighting the need for novel approaches to unravel its underlying mechanisms. Recent advances in microbiome research have shed light on the potential role of the microbiome in reproductive health and outcomes. Based on a systematic literature research, this review aims to comprehensively explore the current understanding of the microbiome's involvement in RPL, focusing on the vaginal, endometrial, and gut microbiomes. Evidence from the available studies is examined to explain the relationship between the microbiome and RPL. Furthermore, we discuss the diagnostic potential of the microbiome, therapeutic interventions, and future directions in microbiome research for RPL. Understanding the complex interactions between the microbiome and reproductive health holds promise for developing targeted interventions to help patients today diagnosed as unexplained.

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.

HLA allele frequency of HLA-A, -B, -C, -DRB1 and -DQB1 in Indian recurrent implantation failure and recurrent pregnancy loss couples - A retrospective study.

The maternal-fetal interaction has been hypothesized to involve the human leucocyte antigen (HLA). It has been suggested that excessive HLA antigen sharing between spouses is a mechanism causing maternal hyporesponsiveness to paternal antigens encountered during pregnancy and thus leading to a miscarriage. Participants in this retrospective study are RIF and RPL couples who visited Gunasheela Surgical and Maternity Hospital, Bangalore, India from November 2019 to September 2022. A total of 40 couples with RIF and 195 couples with RPL are included in the study. We observed that the DQB1*02:01:01 allele is associated with an increase in risk of both RIF and RPL, while the C*12:02:01 allele increases risk of only RPL. On the contrary, DQB1*02:02:01 and DQB1*06:03 alleles appear to be protective against both RPL and RIF. In addition, the C*07:02:01 allele was observed to be protective against RPL. In conclusion, C*12:02:01 and DQB1*02:01:01 could play a major role in RPL which is consistent with other studies, while DQB1*02:01:01 is the risk allele in our RIF group. The protective alleles C*07:02:01 in the RPL group, DQB1*02:02:01, and DQB1*06:03 in both RIF and RPL, were discovered for the first time. Allele frequencies will vary in population-based studies depending on the ethnicities of the cohort. Meta-analysis and antibody testing will provide additional insights on whether and how this data can be adopted into clinical practices.

Immunological parameters of maternal peripheral blood as predictors of future pregnancy outcomes in patients with unexplained recurrent pregnancy loss.

INTRODUCTION: Unexplained recurrent pregnancy loss (URPL), affecting approximately 1%-5% of women, exhibits a strong association with various maternal factors, particularly immune disorders. However, accurately predicting pregnancy outcomes based on the complex interactions and synergistic effects of various immune parameters without an automated algorithm remains challenging. MATERIAL AND METHODS: In this historical cohort study, we analyzed the medical records of URPL patients treated at Xiangya Hospital, Changsha, China, between January 2020 and October 2022. The primary outcomes included clinical pregnancy and miscarriage. Predictors included complement, autoantibodies, peripheral lymphocytes, immunoglobulins, thromboelastography findings, and serum lipids. Least absolute shrinkage and selection operator (LASSO) analysis and logistic regression analysis was performed for model development. The model's performance, discriminatory, and clinical applicability were assessed using area under the curve (AUC), calibration curve, and decision curve analysis, respectively. Additionally, models were visualized by constructing dynamic and static nomograms. RESULTS: In total, 502 patients with URPL were enrolled, of whom 291 (58%) achieved clinical pregnancy and 211 (42%) experienced miscarriage. Notable differences in complement, peripheral lymphocytes, and serum lipids were observed between the two outcome groups. Moreover, URPL patients with elevated peripheral NK cells (absolute counts and proportion), decreased complement levels, and dyslipidemia demonstrated a significantly increased risk of miscarriage. Four models were developed in this study, of which Model 2 demonstrated superior performance with only seven predictors, achieving an AUC of 0.96 (95% CI: 0.93-0.99) and an accuracy of 0.92. A web-based platform was established to visually present model 2 and to facilitate its utilization by clinicians in outpatient settings (available from: https://yingrongli.shinyapps.io/liyingrong/). CONCLUSIONS: Our findings suggest that the implementation of such prediction models could serve as valuable tools for providing comprehensive information and facilitating clinicians in their decision-making processes.

Angiogenic factors and the lectin pathway of complement in women with secondary recurrent pregnancy loss.

The poor remodeling of placental spiral arteries seen in preeclampsia is also discussed to contribute to recurrent pregnancy loss (RPL) preceded by abnormal angiogenesis and excessive complement activation. Low levels of Mannose-binding-lectin (MBL), a pattern recognition molecule (PRM) of the lectin pathway, have been found in women with RPL. We propose that pregnancy loss is connected to defective angiogenesis with reperfusion damage in the placenta and decreased levels of PRM in the lectin pathway in women with RPL. In this cohort study, we investigate the angiogenic factors and the lectin complement pathway in early pregnancy and their time-dependent relationship with pregnancy outcomes in 76 women with secondary RPL (sRPL) who have at least four prior pregnancy losses and a live birth. We evaluated levels of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Vascular Endothelial Growth Factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PRMs, MBL, ficolin-1, -2, -3 and an additional soluble PRM, Pentraxin-3, during the 5th, 6th, and 7th gestational weeks. Our results showed that, compared to live births, pregnancies that ended in loss were associated with elevated VEGF levels and decreased levels of the Ang-2/Ang-1 ratio. Also, increasing levels of ficolin-2 were significantly associated with pregnancy loss, with MBL showing no association. Our research suggests that women with sRPL may have inadequate placentation with impaired angiogenesis in pregnancies ending in a loss.

Systemic Inflammation Response Index and Systemic Immune-inflammation Index for Prediction of Pregnancy Loss: a Case-control Study.

The systemic inflammation response index (SIRI) and systemic immune inflammation index (SII) have recently been investigated as new prognostic markers for obstetric morbidities. However, there are few studies on their predictive role in patients with pregnancy loss. Predicting miscarriages may be useful to support and prevent selected cases.The aim of this study was to investigate the role of SIRI and SII in the prediction of pregnancy loss. A total of 800 patients were included in the retrospective case-control study at a tertiary hospital.Group 1 consisted of 200 patients who had a pregnancy loss for the first time; group 2 consisted of 200 patients with recurrent pregnancy loss; the control group consisted of 400 patients who had a healthy pregnancy. The groups were compared in terms of maternal characteristics, SIRI and SII. Receiver operating characteristic analysis was performed to determine optimal cut-off values for SIRI and SII in predicting pregnancy loss. SIRI and SII were higher in the group with recurrent pregnancy loss than in the control group (p < 0.001).SIRI was higher in the first pregnancy loss group than in the control group (p < 0.001).To predict recurrent pregnancy loss, optimal cut-off values were 1.57 (80% sensitivity, 70% specificity) and 924.12 (74% sensitivity, 57% specificity) for SIRI and SII, respectively. For first pregnancy loss prediction, the optimal cut-off value was 1.38 for SIRI, with 75% sensitivity and 60% specificity. SIRI and SII may be used as inflammatory markers to predict recurrent pregnancy loss. High SIRI values can also help to predict first pregnancy loss.

Bibliometric analysis of the global trends in immune-related recurrent pregnancy loss research over the last two decades.

PROBLEM: A comprehensive analysis was conducted to explore the scientific output on immune-related recurrent pregnancy loss (RPL) and its key aspects. Despite the lack of clear explanations for most RPL cases, immune factors were found to play a significant role. METHOD OF STUDY: The study utilized a bibliometric approach, searching the Web of Science Core Collection database for relevant literature published between 2004 and 2023. RESULTS: The collected dataset consisted of 2228 articles and reviews, revealing a consistent increase in publications and citations over the past two decades. The analysis identified the United States and China as the most productive countries in terms of RPL research. Among the institutions, Fudan University in China emerged as the top contributor, followed by Shanghai Jiaotong University. Kwak-kim J was the most prolific author, while Christiansen Ob had the highest number of co-citations. The top 25 co-cited references on diagnosis, treatment, and mechanisms formed the foundation of knowledge in this field. By examining keyword co-occurrence and co-citations, the study found that antiphospholipid syndrome and natural killer cells were the primary areas of focus in immune-related RPL research. Additionally, three emerging hotspots were identified: chronic endometritis, inflammation, and decidual macrophages. These aspects demonstrated increasing interest and research activity within the field of immune-related RPL. CONCLUSIONS: Overall, this comprehensive bibliometric analysis provided valuable insights into the patterns, frontiers, and focal points of global scientific output related to immune-related RPL.

Pyroptosis is involved in the immune microenvironment regulation of unexplained recurrent miscarriage.

Unexplained recurrent miscarriage (URM) is a common pregnancy complication with few effective therapies. Moreover, little is known regarding the role of pyroptosis in the regulation of the URM immune microenvironment. To address this issue, gene expression profiles of publicly available placental datasets GSE22490 and GSE76862 were downloaded from the Gene Expression Omnibus database. Pyroptosis-related differentially expressed genes were identified and a total of 16 differentially expressed genes associated with pyroptosis were detected, among which 1 was upregulated and 15 were downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that the functionally enriched modules and pathways of these genes are closely related to immune and inflammatory responses. Four hub genes were identified: BTK, TLR8, NLRC4, and TNFSF13B. BTK, TLR8, and TNFSF13B were highly connected with immune cells, according to the correlation analysis of four hub genes and 20 different types of immune cells (p < 0.05). The four hub genes were used as research objects to construct the interaction networks. Chorionic villus tissue was used for quantitative real-time polymerase chain reaction and western blot to confirm the expression levels of hub genes, and the results showed that the expression of the four hub genes was significantly decreased in the chorionic villus tissue in the URM group. Collectively, the present study indicates that perhaps pyroptosis is essential to the diversity and complexity of the URM immune microenvironment, and provides a theoretical basis and research ideas for subsequent target gene verification and mechanism research.

JPT2 Affects Trophoblast Functions and Macrophage Polarization and Metabolism, and Acts as a Potential Therapeutic Target for Recurrent Spontaneous Abortion.

Recurrent spontaneous abortion (RSA) is a pregnancy-related condition with complex etiology. Trophoblast dysfunction and abnormal macrophage polarization and metabolism are associated with RSA; however, the underlying mechanisms remain unknown. Jupiter microtubule-associated homolog 2 (JPT2) is essential for calcium mobilization; however, its role in RSA remains unclear. In this study, it is found that the expression levels of JPT2, a nicotinic acid adenine dinucleotide phosphate-binding protein, are decreased in the villous tissues of patients with RSA and placental tissues of miscarried mice. Mechanistically, it is unexpectedly found that abnormal JPT2 expression regulates trophoblast function and thus involvement in RSA via c-Jun N-terminal kinase (JNK) signaling, but not via calcium mobilization. Specifically, on the one hand, JPT2 deficiency inhibits trophoblast adhesion, migration, and invasion by inhibiting the JNK/atypical chemokine receptor 3 axis. On the other hand, trophoblast JPT2 deficiency contributes to M1 macrophage polarization by promoting the accumulation of citrate and reactive oxygen species via inhibition of the JNK/interleukin-6 axis. Self-complementary adeno-associated virus 9-JPT2 treatment alleviates embryonic resorption in abortion-prone mice. In summary, this study reveals that JPT2 mediates the remodeling of the immune microenvironment at the maternal-fetal interface, suggesting its potential as a therapeutic target for RSA.

Inflammation in recurrent miscarriage - a comprehensive perspective from uterine microenvironment and immune cell imbalance to therapeutic strategies.

Recurrent miscarriage, poses a significant challenge for many couples globally, the causes of which are not fully understood. Recent studies have shown the intricate link between uterine inflammation and recurrent miscarriages. While inflammation is essential during early pregnancy stages, especially in embryo implantation, an imbalance can lead to miscarriage. Key inflammatory mediators and an imbalance in immune cells can significantly alter and contribute to recurrent miscarriages. Lifestyle factors like smoking and obesity exacerbate inflammatory responses, increasing miscarriage risks. Understanding the interaction between the uterine environment, immune cell imbalances, and recurrent miscarriages is essential for devising effective treatments. This paper presents the latest data on inflammation's role in recurrent miscarriage, emphasizing the significance of diagnosing chronic endometritis and immune imbalances, offering practical recommendations for treatment and diagnosis.

T Cell Subsets and the Expression of Related MicroRNAs in Patients with Recurrent Early Pregnancy Loss.

This study explored the role of T cell subsets and the expression of related microRNAs in patients with recurrent early pregnancy loss (EPL). Fifty patients with EPL loss between May 2018 and May 2021 were randomly selected as the EPL group, and 50 pregnant women with normal pregnancies or normal delivery outcomes were randomly selected as the control group. The expression levels of T cell subset-related markers and T cell subset-related miRNAs, in addition to the frequencies of T cell subsets, in peripheral blood of the two groups were analyzed. In terms of T cell-related markers, the results showed that the expression levels of the transcriptional regulator TBX-21 (T-bet) and interferon regulatory factor 4 (IRF4) were significantly upregulated in peripheral blood of the patients in the EPL group (P < 0.05), whereas the expression levels of GATA binding protein 3 (GATA3) and glucocorticoid-induced tumor necrosis factor receptor (GITR) were significantly downregulated (P < 0.05). In the EPL group, the expression of mir-106b, mir-93, and mir-25 was upregulated (1.51 ± 0.129, 1.43 ± 0.132, and 1.73 ± 0.156, respectively) in regulatory T (Treg) cell-related T cell subsets, whereas the expression of miR-146a and miR-155 was downregulated (P < 0.05). The frequencies of Treg and exhausted T cells in the EPL group were significantly lower than those in the control group (P < 0.05). The cell frequencies of T helper 17 (Th17) cells and exhausted Treg cells in the EPL group were significantly higher than those in the control group (P < 0.05). In conclusion, immune cells and associated miRNA profiles can be used as prognostic biomarkers for the treatment of human reproductive disorders, such as EPL.

Increased cytotoxic natural killer cells in the endometrium alone cannot be considered the immunological cause of recurrent miscarriage.

OBJECTIVE: To study the distribution and gene expression of endometrial immune cell populations, especially natural killer (NK) subsets, between assisted reproductive technology patients and healthy donors and explore a possible relationship of these results with patients' killer cell immunoglobulin-like receptor (KIR) genotypes and KIR-human antigen leukocyte-C (HLA-C) binding. DESIGN: Prospective observational cohort study. SETTING: Clinic and university laboratories. PATIENT(S): Participants included 39 women with recurrent miscarriages who had undergone in vitro fertilization cycles with donated oocytes and 21 healthy oocyte donors with proven fertility. INTERVENTION(S): Endometrial biopsy samples were collected from both patients and donors, and the KIR genotypes of the assisted reproductive technology patients were analyzed. MAIN OUTCOME MEASURE(S): Endometrial gene expression (cluster of differentiation [CD] antigens and anti-inflammatory and proinflammatory interleukins) and the number and percentage of regulatory T and NK cell populations in patients and donors were determined. Subsequently, the results obtained were categorized in the group of patients by KIR genotype. Killer cell immunoglobulin-like receptor-HLA-C binding was also examined in patients, considering their KIRs. RESULT(S): A higher percentage of CD56dimCD16+ NK cells were observed in patients than those in healthy donors. Nevertheless, when categorizing patients by KIR genotype and comparing the KIR AA (35.9%), AB (43.6%), and BB (20.5%) groups, no statistically significant difference was observed in either endometrial gene expression or any of the immune cell populations analyzed. Finally, no differences in binding between KIR and HLA-C molecules were registered among these 3 sets of patients. CONCLUSION(S): The reported increase in the number of NK cells with a cytotoxic profile in the endometrium of women with a history of recurrent miscarriages cannot alone explain these events because no relationship is observed between such cellular increase and the KIR genotypes, which individually, and in combination with the different HLA-C alleles, have also been associated, by previous studies, with negative reproductive outcomes. CLINICAL TRIAL REGISTRATION NUMBER: 1405-MAD-025-JG.

The association of IL-3, IL-17A, and IL 27 serum levels with susceptibility to toxoplasmosis in recurrent abortion of Iraqi women.

Cytokines are a group of immunomodulatory proteins leading to a variety of immune reactions in the human; these cytokines play a significant role in the development of appropriate immune responses against T. gondii. This study aims to reveal the association of toxoplasmosis with serum levels of IL-3, IL-17A, and IL-27 in aborted women. The blood samples of patients and controls were collected from Al-Alawiya Maternity Teaching Hospital/Baghdad/Iraq from 2019 to 2020 for detecting anti-T. gondii antibodies (IgG and IgM) and the level of interleukins by ELISA. The results of TORCH by rapid test for recurrent abortion recorded 25.3% seropositive for anti-Toxoplasma antibodies, and 31.5% seropositive for one or more cases of TORCH test (Cytomegalovirus, Rubella, and Herpes). Whereas the results for anti-T. gondii IgG and IgM antibodies were shown elevated positivity percentages by ELISA test; these percentages were 56.2% in recurrent abortion women with significant differences (P < 0.05). The results suggested that the IL-3 serum concentration of pregnant women, recurrent abortion, and recurrent abortion with toxoplasmosis was declined versus healthy women with significant differences (p < 0.05). However, the results revealed that the concentration of IL-17A in recurrent abortion, and recurrent abortion with toxoplasmosis elevated versus healthy women and pregnant women with significant difference (p < 0.05). Whereas the results indicated that the IL-27 serum concentration elevated with significant differences in recurrent abortion with toxoplasmosis group compared to healthy women, pregnant women, and recurrent abortion. Interestingly, the serum levels for IL-27 increased comparing to the levels of IL-3 and IL-17A in all groups with significant differences (P < 0.05). In conclusion, it appeared in this study that the role of IL-3, IL-17A, and IL-27 in the maternal immune response during infections can lead to abortion.

Characterisation of peri-implantation endometrial Treg and identification of an altered phenotype in recurrent pregnancy loss.

Recurrent Pregnancy Loss (RPL) affects 2-4% of couples, and with increasing numbers of pregnancy losses the risk of miscarrying a euploid pregnancy is increased, suggesting RPL is a pathology distinct from sporadic miscarriage that is due largely to lethal embryonic aneuploidy. There are a number of conditions associated with RPL including unspecified "immune" pathologies; one of the strongest candidates for dysregulation remains T regulatory cells as depletion in the very early stages of pregnancy in mice leads to pregnancy loss. Human endometrial Treg and conventional CD4T cells were isolated during the peri-implantation period of the menstrual cycle in normal women. We identified an endometrial Treg transcriptomic signature and validated an enhanced regulatory phenotype compared to peripheral blood Treg. Parous women had an altered endometrial Treg transcriptome compared to nulliparity, indicating acquired immune memory of pregnancy within the Treg population, by comparison endometrial conventional CD4T cells were not altered. We compared primary and secondary RPL to nulliparous or parous controls respectively. Both RPL subgroups displayed differentially expressed Treg gene transcriptomes compared to controls. We found increased cell surface S1PR1 and decreased TIGIT protein expression by Treg in primary RPL, confirming the presence of altered Treg in the peri-implantation RPL endometrium.

Mesenchymal stem cell therapy attenuates complement C3 deposition and improves the delicate equilibrium between angiogenic and anti-angiogenic factors in abortion-prone mice.

Immunological disorders are one of the main causes of recurrent spontaneous abortions (RSA). A rapidly expanding body of evidence indicates that excessive activation of the complement system is critically involved in the development of miscarriages. In the CBA/J × DBA/2 murine model of recurrent miscarriage, exaggerated and unrestrained complement activation is reported to be the underlying cause of angiogenic factor imbalance and persistent inflammation. We have previously shown that mesenchymal stem cell (MSC) therapy can significantly reduce the abortion rate in abortion-prone mice through regulating the feto-maternal immune response. In the present study, we hypothesized that MSCs might improve the balance of angiogenic factors at the feto-maternal unit of CBA/J × DBA/2 mice by restraining complement activation and deposition. To explore this hypothesis, autologous adipose tissue-derived mesenchymal stem cells (AD-MSCs) were administered intra-peritoneally to abortion-prone mice on the 4.5th day of gestation. Control mice received PBS as vehicle. On day 13.5 of pregnancy, deposition of the complement component C3 and expression levels of Crry, CFD (adipsin), VEGF, PlGF and FLT-1 were measured at the feto-maternal interface by immunohistochemistry and real-time PCR, respectively. Decidual cells were also cultured in RPMI 1640 medium for 48 h and VEGF and sFLT-1 protein levels were quantified in supernatants using enzyme-linked immunosorbent assay (ELISA). Our results indicated that MSC therapy significantly reduced C3 deposition and adipsin transcription in the fetal-maternal interface of abortion-prone mice. Furthermore, administration of MSCs robustly upregulated the mRNA expression levels of Crry, VEGF, PlGF and FLT-1 in the placenta and decidua of CBA/J × DBA/2 mice. Consistently, the in vitro results demonstrated that decidual cells obtained from MSC-treated dams produced increased concentrations of VEGF in culture supernatants, with concomitant decreased levels of sFLT-1 protein. Here, we show for the first time that adoptive transfer of MSCs rectifies the disturbed balance of angiogenic factors observed at the feto-maternal unit of CBA/J × DBA/2 mice, in part at least, through inhibiting excessive complement activation and promoting the production of angiogenic factors. Collectively, these alterations seem to play a pivotal role in reducing the abortion rate and improving the intrauterine condition for the benefit of the fetus.

Association between genetic polymorphism of IL-27 (rs153109) and toxoplasmosis in Iraqi women with recurrent abortion.

Single nucleotide polymorphisms (SNPs) are predictive markers for diseases, also cytokines are undergoing genetic controls and their genetic polymorphisms have a functional role in regulating the levels of cytokine gene expression. This study aims to reveal the association of toxoplasmosis with serum levels and SNP of IL-27 in aborted women. Total, 200 blood samples of patients and controls were collected from Al-Alawiya Maternity Teaching Hospital/Baghdad/Iraq from 2019­2020 for detecting the level of IL-27 by ELISA while the allelic discrimination method was used for SNP IL-27 (rs153109). The results indicated the IL-27 serum concentration elevated with significant differences in recurrent abortion with toxoplasmosis group compared to healthy women, pregnant women, and recurrent abortion. Also, recurrent abortion had significant differences compared to healthy women and pregnant women (P<0.05). Moreover, SNP results of IL-27 showed no significant association between patients and controls. Considering the distribution of serum levels for IL-27 by SNP, it was observed that IL-27 serum levels for TT, TC, and CC genotypes elevated in the patient group versus the control group. In addition, it was observed elevation serum level of IL-27 for the genotypes TT, TC, and CC in recurrent abortion with toxoplasmosis in contrast to healthy women, pregnant women, and recurrent abortion (P<0.05). Also, in recurrent abortion, the level of IL-27 for TC, and CC genotype showed significant differences comparing to healthy and pregnant women (P<0.05). In conclusion, the level of IL-27 in recurrent abortion women with toxoplasmosis was higher than the recurrent abortion women, which may be due to the inflammatory response to toxoplasmosis. SNP of IL-27 has not represented as a risk factor in recurrent abortion women with toxoplasmosis.