Joining the immunological dots in recurrent miscarriage

Recurrent Pregnancy Loss: Immunological aetiologies and associations with mental health

Recurrent pregnancy loss (RPL) is an obstetric condition estimated to affect 2-4% of childbearing individuals globally. Due to its varied nature, medical societies globally differ in their diagnostic criteria. Its aetiologies are numerous, ranging from anatomic abnormalities to endocrine and immunological factors. Autoimmune factors can attribute to approximately 20% of cases and include dysregulation of immune cells, cytokine production and antiphospholipid syndrome. Treatment pathways vary by aetiology; however, many cases remain unexplained, adding an additional level of complexity to this condition. Due to its recurrent nature, this type of pregnancy loss has profound impacts on mental health during subsequent pregnancies. While some aspects of RPL have been widely investigated, there continues to be a gap in research, such as its impacts on non-birthing parents and specific sociodemographic groups.

Impact of the adenosine receptor A2BR expressed on myeloid cells on immune regulation during pregnancy

During pregnancy, the maternal immune system must carefully balance protection against pathogens with tolerance toward the semiallogeneic fetus. Dysfunctions of the immune system can lead to severe complications such as preeclampsia, fetal growth restriction, or pregnancy loss. Adenosine plays a role in physiological processes and plasma-level increase during pregnancy. The adenosine receptor A2B (A2BR), which is expressed on both, immune and nonimmune cells, is activated by high adenosine concentrations, achieved during pregnancy. We investigated the impact of A2BR expressed on myeloid cells on immune regulation during pregnancy using a mouse model with myeloid deficiency for A2BR. We demonstrate systemic changes in myeloid and lymphoid cell populations during pregnancy in A2BR-KO (Adora2B923f/f-LysMCre) mice with increased monocytes, neutrophils, and T cells but decreased B cells as well as altered T-cell subpopulations with decreased Th1 cells and Tregs and increased Th17 cells. Lack of A2BR on myeloid cells caused an increased systemic expression of IL-6 but decreased systemic accumulation and function of MDSC and reduced numbers of uterine natural killer cells. The pregnancy outcome was only marginally affected. Our results demonstrate that A2BR on myeloid cells plays a role in immune regulation during pregnancy, but the clinical impact on pregnancy remains unclear.

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.

Association of XIST/miRNA155/Gab2/TAK1 cascade with the pathogenesis of anti-phospholipid syndrome and its effect on cell adhesion molecules and inflammatory mediators

Anti-phospholipid syndrome (APS) is an autoimmune disease characterized by thrombosis and miscarriage events. Still, the molecular mechanisms underlying APS, which predisposes to a wide spectrum of complications, are being explored. Seventy patients with primary and secondary APS were recruited, in addition to 35 healthy subjects. Among APS groups, the gene expression levels of XIST, Gab2, and TAK1 were higher along with declined miRNA155 level compared with controls. Moreover, the sera levels of ICAM-1, VCAM-1, IL-1ꞵ, and TNF-α were highly elevated among APS groups either primary or secondary compared with controls. The lncRNA XIST was directly correlated with Gab2, TAK1, VCAM-1, ICAM-1, IL-1ꞵ, and TNF-α. The miRNA155 was inversely correlated with XIST, Gab2, and TAK1. Moreover, ROC curve analyses subscribed the predictive power of the lncRNA XIST and miRNA155, to differentiate between primary and secondary APS from control subjects. The lncRNA XIST and miRNA155 are the upstream regulators of the Gab2/TAK1 axis among APS patients via influencing the levels of VCAM-1, ICAM-1, IL1ꞵ, and TNF-α which propagates further inflammatory and immunological streams. Interestingly, the study addressed that XIST and miRNA155 may be responsible for the thrombotic and miscarriage events associated with APS and provides new noninvasive molecular biomarkers for diagnosing the disease and tracking its progression.

Comprehensive molecular expression profiling of SARS-CoV-associated factors in the endometrium across the menstrual cycle and elevated susceptibility in women with recurrent pregnancy loss

Objective: To evaluate the dynamic expression profiling alterations of SARS-CoV-2-associated molecules within the fertile human endometrium throughout the menstrual cycle. Furthermore, to explore the inherent vulnerability of the endometrium to SARS-CoV-2 infection among women experiencing recurrent pregnancy failure, including both recurrent implantation failures (RIF) and recurrent pregnancy losses (RPL). Method: The present study employed multiple datasets to investigate the expression patterns of SARS-CoV-2-associated genes. Firstly, a single-cell RNA-sequencing dataset comprising endometrial samples from 19 healthy women across the menstrual cycle was utilized. Additionally, two microarray datasets encompassing 24 women with RIF, and 24 women with RPL during the peri-implantation phase were included. To complement these analyses, immunohistochemical (IHC) staining was performed on endometrial samples collected from 30 women with RIF, 30 women with RPL, and 20 fertile controls recruited specifically during the implantation period. Results: The investigation revealed a moderate expression percentage of CTSL (22%), TMPRSS4 (15%), FURIN (16%) and MX1 (9%) in endometrium. Conversely, the expression percentages of ACE2 (1%) and TMPRSS2 (4%) were relatively low. Notably, the expression of BSG exhibited an increment towards the window of implantation, reaching its peak during the middle secretary phase. Furthermore, a significant reduction (p < 0.05) in TMPRSS2 expression was observed in the RIF group compared to the control group. While the expression of BSG was significantly increased (p < 0.05) in the RPL group, findings that were corroborated by the IHC staining results. Conclusion: The findings of this study indicate a noteworthy upregulation of BSG expression in the endometrium of women with RPL. These results suggest an augmented susceptibility of endometrium to SARS-CoV-2 infection, potentially contributing to unfavorable pregnancy outcomes.

Intracellular Lipid Accumulation Drives the Differentiation of Decidual Polymorphonuclear Myeloid-Derived Suppressor Cells via Arachidonic Acid Metabolism

Decidual polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are essential to immune tolerance during pregnancy. A reduction in the number of these cells is associated with unexplained recurrent pregnancy loss (URPL). In our previous study, we reported that PMN-MDSCs are a group of mature neutrophils that are activated by the decidua microenvironment. In the present study, we show that the decidua microenvironment induces substantial lipid accumulation in neutrophils during their differentiation to PMN-MDSCs. Lower levels of lipid accumulation are detected in PMN-MDSCs from URPL patients, and the amount of lipid in the PMN-MDSCs is positively correlated with the proportion of PMN-MDSCs. Next, we demonstrate that decidua-derived IL6 with the presence of arachidonic acid upregulates fatty acid-binding protein 5 (FABP5) via the phosphorylation of signal transducer and activator of transcription 3 (STAT3). Fy -60ABP5 then continuously stimulates intracellular lipid accumulation. Increased intracellular lipid accumulation mediates arachidonic acid metabolism, a pathway that is significantly activated by the induction of the decidua microenvironment, to stimulate the synthesis of prostaglandin E2 (PGE2) and finally induce the differentiation of PMN-MDSCs. To summarize, decidua-derived IL6 facilitates the differentiation of PMN-MDSCs from neutrophils via the pSTAT3/FABP5/PGE2 pathway. Defects in the process may result in impaired differentiation and dysfunction of PMN-MDSCs in URPL. These findings enhance our understanding of the physiological mechanisms of immune tolerance in pregnancy and provide therapeutic options for URPL.

Undifferentiated Connective Tissue Disease in Pregnancy: A Topic Yet to be Explored

Undifferentiated connective tissue disease (UCTD) is characterized by signs and symptoms suggestive of a connective tissue disease (CTD), but not fulfilling criteria for a specific CTD. Although UCTD is probably the most common rheumatic disease diagnosed in pregnant women, data about disease course during pregnancy and perinatal outcomes are very limited. Compared to other CTDs, UCTD seems to have milder clinical manifestations in pregnancy. Its natural history is related to disease activity at conception. In fact, if the disease is in a state of remission or minimal activity at conception, pregnancy outcomes are generally good. On the contrary, patients who become pregnant in a moment of high disease activity and/or who have multiple antibodies positivity show an increased risk of disease flares, evolution to a definite CTD and obstetric complications, such as fetal growth restriction, preeclampsia and preterm birth. Therefore, a preconception assessment is essential in women with UCTD to evaluate maternal and fetal risks, to initiate interventions to optimize disease activity, and to adjust medications to those that are least harmful to the fetus. The aim of the present study was to review the available literature about pregnancy course, maternal and fetal outcomes and therapeutic approaches of pregnant women with UCTD.

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.

A three-arm, multicenter, open-label randomized controlled trial of hydroxychloroquine and low-dose prednisone to treat recurrent pregnancy loss in women with undifferentiated connective tissue diseases: protocol for the Immunosuppressant regimens for LIving FEtuses (ILIFE) trial

Background

Undifferentiated connective tissue disease (UCTD) is known to induce adverse pregnancy outcomes and even recurrent spontaneous abortion (RSA) by placental vascular damage and inflammation activation. Anticoagulation can prevent pregnancy morbidities. However, it is unknown whether the addition of immune suppressants to anticoagulation can prevent spontaneous pregnancy loss in UCTD patients. The purpose of this study is to evaluate the efficacy of hydroxychloroquine (HCQ) and low-dose prednisone on recurrent pregnancy loss for women with UCTD.

Methods

The Immunosuppressant for Living Fetuses (ILIFE) Trial is a three-arm, multicenter, open-label randomized controlled trial with the primary objective of comparing hydroxychloroquine combined with low-dose prednisone and anticoagulation with anticoagulation alone in treating UCTD women with recurrent spontaneous abortion. The third arm of using hydroxychloroquine combined with anticoagulant for secondary comparison. A total of 426 eligible patients will be randomly assigned to each of the three arms with a 1:1:1 allocation ratio. The primary outcome is the rate of live births. Secondary outcomes include adverse pregnancy outcomes and progression of UCTD.

Discussion

This is the first multi-center, open-label, randomized controlled trial which evaluates the efficacy of immunosuppressant regimens on pregnancy outcomes and UCTD progression. It will provide evidence on whether the immunosuppressant ameliorates the pregnancy prognosis in UCTD patients with RSA and the progression into defined connective tissue disease.

Trial registration

ClinicalTrials.gov NCT03671174. Registered on 14 September 2018.

Weighted gene correlation network analysis reveals novel regulatory modules associated with recurrent early pregnancy loss

At present, the etiology and pathogenesis of recurrent early pregnancy loss (REPL) are not completely clear. Therefore, identifying the underlying diagnostic and prognostic biomarkers of REPL can provide new ideas for the diagnosis and treatment of REPL. The chip data of REPL (GSE63901) were downloaded from the NCBI Gene Expression Omnibus (GEO) database. Weighted Gene Co-Expression Network Analysis (WGCNA) was used to construct a co-expression module for studying the relationship between gene modules and clinical features. In addition, functional analysis of hub genes in modules of interest was performed. A total of 23 co-expression modules were identified, two of which were most significantly associated with three clinical features. The MEbrown module was positively correlated with cyclin E level and the out-of-phase trait while the MEred module was positively correlated with the effect of progesterone. We identified 17 hub genes in the MEred module. The functional enrichment analysis indicated that such hub genes were mainly involved in pathways related to cellular defense response and natural killer (NK) cell-mediated cytotoxicity. In the MEbrown module, we identified 19 hub genes, which were mainly enriched in cell adhesion molecule production, regulation of cellular response to growth factor stimulus, epithelial cell proliferation, and transforming growth factor-β (TGF-β) signaling pathway. In addition, the hub genes were validated by using other datasets and three true hub genes were finally obtained, namely DOCK2 for the MEred module, and TRMT44 and ERVMER34-1 for the MEbrown module. In conclusion, our results screened potential biomarkers that might contribute to the diagnosis and treatment of REPL.

Detecting the Effects of Early-Life Exposures: Why Fecundity Matters

Prenatal exposures have meaningful effects on health across the lifecourse. Innovations in causal inference have shed new light on these effects. Here, we motivate the importance of innovation in the characterization of fecundity, and prenatal selection in particular. We argue that such innovation is crucial for expanding knowledge of the fetal origins of later life health. Pregnancy loss is common, responsive to environmental factors, and closely related to maternal and fetal health outcomes. As a result, selection into live birth is driven by many of the same exposures that shape the health trajectories of survivors. Lifecourse effects that are inferred without accounting for these dynamics may be significantly distorted by survival bias. We use a set of Monte Carlo simulations with realistic parameters to examine the implications of prenatal survival bias. We find that even in conservatively specified scenarios, true fetal origin effects can be underestimated by 50% or more. In contrast, effects of exposures that reduce the probability of prenatal survival but improve the health of survivors will be overestimated. The absolute magnitude of survival bias can even exceed small effect sizes, resulting in inferences that beneficial exposures are harmful or vice-versa. We also find reason for concern that moderately sized true effects, underestimated due to failure to account for selective survival, are missing from scientific knowledge because they do not clear statistical significance filters. This bias has potential real-world costs; policy decisions about interventions to improve maternal and infant health will be affected by underestimated program impact.

Myeloid-derived suppressor cells depletion may cause pregnancy loss via upregulating the cytotoxicity of decidual natural killer cells

PROBLEM

Maternal immune system tolerance to the semiallogeneic fetus is critical for a successful pregnancy. Studies have shown that myeloid-derived suppressor cells (MDSCs) play an important role in maintaining feto-maternal tolerance. However, the mechanisms remain poorly understood.

METHODS

Flow cytometry was used to evaluate the percentage of MDSCs in an allogeneic-normal-pregnant mouse model during different periods of gestation. We further assessed the percentage of MDSCs and their subtypes (granulocytic MDSCs [GR-MDSCs] and monocytic MDSCs [MO-MDSCs]) in a spontaneous abortion mouse model. The levels of the immunosuppressive molecules ARG-1, iNOS, IL-10, and TGF-β in MDSCs were also evaluated. MDSCs were depleted by anti-Gr-1 injection, and the resorption rate was calculated. The cytotoxicity of decidual natural killer (NK) cells was evaluated, and the percentage of regulatory NK (NKreg) cells and regulatory T lymphocytes (Tregs) were evaluated.

RESULTS

Myeloid-derived suppressor cells was accumulated in a time-dependent manner during pregnancy. However, the percentage of MDSCs was decreased in the spontaneous abortion mice compared with that in the control mice. In addition, the levels of ARG-1, iNOS, IL-10, and TGF-β in MDSCs decreased differentially. Finally, depletion of MDSCs was associated with increased rates of resorption and the proportion of NKreg and Treg cells in uterine tissues; meanwhile, the cytotoxicity of decidual NK cells was upregulated by increasing the level of perforin, granzyme B, and natural killer group protein 2 D-activating NK receptor (NKG2D).

CONCLUSION

Depletion of MDSCs may cause pregnancy loss, while upregulating the cytotoxicity of decidual NK cells and increasing NKreg and Treg cell numbers.

Human Chorionic Gonadotropin: The Pregnancy Hormone and More

To thoroughly review the uses of human chorionic gonadotropin (hCG) related to the process of reproduction and also assess new, non-traditional theories. Review of the international literature and research studies. hCG and its receptor, LH/CGR, are expressed in numerous sites of the reproductive tract, both in gonadal and extra-goanadal tissues, promoting oocyte maturation, fertilization, implantation and early embryo development. Moreover, hCG seems to have a potential role as an anti-rejection agent in solid organ transplantation. Future research needs to focus extensively on the functions of hCG and its receptor LH/CGR, in an effort to reveal known, as well as unknown clinical potentials.

Smoking, HIV, and risk of pregnancy loss

OBJECTIVE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSION

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

Women with Recurrent Miscarriage Have Decreased Expression of 25-Hydroxyvitamin D3-1α-Hydroxylase by the Fetal-Maternal Interface

Background

Effects of vitamin D deficiency in pregnancy have been associated with some adverse pregnancy outcomes. The 25-hydroxyvitamin D₃-1α-hydroxylase (CYP27B1) is integral to the vitamin D metabolic pathway. The enzyme catalyzes localized conversion of pro-hormone 25-hydroxyvitamin D₃ to active 1,25-dihydroxyvitamin D₃. Our aim was to investigate the expression of CYP27B1 at the fetal-maternal interface in the first trimester pregnancy and to determine whether CYP27B1 was associated with recurrent miscarriage (RM).

Methods

Expressions of CYP27B1 mRNA and protein in villi and decidua from 20 women undergoing primary miscarriage, 20 women with RM and 20 women with normal pregnancy were evaluated by western blot, and quantitative real-time PCR. The co-localization of CYP27B1 and certain cytokines including IL-10, IFN-γ, TNF-α, and IL-2 expression were examined using immunohistochemistry and confocal microscopy.

Results

Women with RM had a significantly lower expression of CYP27B1 mRNA and protein in villous and decidual tissues compared with the normal pregnant women (P = 0.000 in villus, P = 0.002 in decidua for mRNA; P = 0.036 in villus, P = 0.007 in decidua for protein.). Compared with the normal pregnancy, immunostaining for CYP27B1 was significantly decreased in villous trophoblasts and decidual glandular epithelial cells in RM women. No significant differences in the localization of CYP27B1, IL-10, IFN-γ, TNF-α, and IL-2 expression were identified between the normal pregnant and RM women.

Conclusions

Women with RM have a lower level of CYP27B1 expression in chorionic villi and decidua compared with normal pregnant women, suggesting that reduced CYP27B1 expression may be associated with RM. The consistent localization of CYP27B1 and IL-10, IFN-γ, TNF-α, and IL-2 expression in villous and decidual tissues suggests the importance of the local production of 1,25(OH)₂D₃ at the fetal-maternal interface to regulate cytokine responses.

Partnered sexual activity moderates menstrual cycle-related changes in inflammation markers in healthy women: an exploratory observational study

OBJECTIVE

To examine differences in inflammation markers in sexually active versus abstinent women and observe changes in inflammation markers across the menstrual cycle. Cycle-related immune fluctuations may have evolved to reduce interference with conception. If so, reproductively active (i.e., sexually active) women should show the most variability in cytokine expression.

DESIGN

Participants provided serum samples at menses and ovulation (from which cytokines were assayed) and saliva samples at menses and during follicular, ovulation, and luteal phases (from which C-reactive protein [CRP] was assayed). Participants self-reported intercourse frequency during the study.

SETTING

Academic research laboratory.

PATIENT(S)

Thirty-two healthy, naturally cycling premenopausal women (sexually active, n = 15; abstinent, n = 17).

INTERVENTION(S)

Observational study.

MAIN OUTCOME MEASURE(S)

Levels of proinflammatory cytokines (interleukin-6 [IL-6], interferon γ [IFN-γ], tumor necrosis factor-α [TNF-α]), an anti-inflammatory cytokine (interleukin-4 [IL-4]), and a marker of total inflammation (CRP).

RESULT(S)

Sexually active women had higher levels of all of the immune markers measured, including both pro- and anti-inflammatory cytokines, than abstinent women. Relative to sexually active women, abstinent women had less change across the menstrual cycle in levels of CRP. Among sexually active women, higher intercourse frequency predicted greater midcycle decreases in CRP, IL-6, and IFN-γ and midcycle increases in IL-4.

CONCLUSION(S)

Sexual activity may stimulate a complex interaction between pro- and anti-inflammatory cytokines that subsequently drives midcycle declines in inflammation.

Immunogenetic contributions to recurrent pregnancy loss

While sporadic pregnancy loss is common, occurring in 15 % of pregnancies, recurrent pregnancy loss (RPL) impacts approximately 5 % of couples. Though multiple causes are known (including structural, hormonal, infectious, autoimmune, and thrombophilic causes), after evaluation, roughly half of all cases remain unexplained. The idiopathic RPL cases pose a challenging therapeutic dilemma in addition to incurring much physical and emotional morbidity. Immunogenetic causes have been postulated to contribute to these cases of RPL. Natural Killer cell, T cell expression pattern changes in the endometrium have both been shown in patients with RPL. Human leukocyte antigen (HLA) and cytokine allelic variations have also been studied as etiologies for RPL. Some of the results have been promising, however the studies are small and have not yet put forth outcomes that would change our current diagnosis and management of RPL. Larger database studies are needed with stricter control criteria before reasonable conclusions can be drawn.

Interleukin-17 and leptin genes polymorphisms and their levels in relation to recurrent pregnancy loss in Egyptian females

Recurrent pregnancy loss (RPL) is a common problem during early gestation. The aim of our study was to investigate the association of IL-17 F( rs763780), IL-17 A (rs2275913), and leptin (2548 G/A) gene polymorphisms with RPL in obese and lean Egyptian females, and to find out whether these gene polymorphisms affect the women’s serum levels. One hundred and twenty patients with RPL and 120 fertile volunteers with no history of pregnancy loss were genotyped for leptin (2548 G/A), IL-17 A (rs2275913), and IL-17 F (rs763780) polymorphisms by RFLP. The serum level of IL-17 was measured by ELISA, while serum leptin level was measured by HPLC. We found that IL-17 F (rs763780) polymorphism was associated with a decreased risk of RPL in Egyptian females, and we also found that IL-17 A (rs2275913) and LEP (2548 G/A) SNP were associated with an increased risk of RPL. We also demonstrated that both the IL-17 and leptin levels were elevated in the women with RPL and in an obese subgroup within RPL in comparison to a lean one.

Peripheral blood natural killer cells and mild thyroid abnormalities in women with reproductive failure

Abnormalities in peripheral blood natural killer (NK) cells have been reported in women with primary infertility and recurrent spontaneous abortion (RSA) and several studies have been presented to define cutoff values for abnormal peripheral blood NK cell levels in this context. Elevated levels of NK cells were observed in infertile/RSA women in the presence of thyroid autoimmunity (TAI), while no studies have been carried out, to date, on NK cells in infertile/RSA women with non-autoimmune thyroid diseases. The contribution of this study is two-fold: (1) the evaluation of peripheral blood NK cell levels in a cohort of infertile/RSA women, in order to confirm related data from the literature; and (2) the assessment of NK cell levels in the presence of both TAI and subclinical hypothyroidism (SCH) in order to explore the possibility that the association between NK cells and thyroid function is not only restricted to TAI but also to SCH. In a retrospective study, 259 age-matched women (primary infertility [n = 49], primary RSA [n = 145], and secondary RSA [n = 65]) were evaluated for CD56+CD16+NK cells by flow cytometry. Women were stratified according to thyroid status: TAI, SCH, and without thyroid diseases (ET). Fertile women (n = 45) were used as controls. Infertile/RSA women showed higher mean NK cell levels than controls. The cutoff value determining the abnormal NK cell levels resulted ⩾15% in all the groups of women. Among the infertile/RSA women, SCH resulted the most frequently associated thyroid disorder while no difference resulted in the prevalence of TAI and ET women between patients and controls. A higher prevalence of women with NK cell levels ⩾15% was observed in infertile/RSA women with SCH when compared to TAI/ET women. According to our data, NK cell assessment could be used as a diagnostic tool in women with reproductive failure and we suggest that the possible association between NK cell levels and thyroid function can be described not only in the presence of TAI but also in the presence of non-autoimmune thyroid disorders.

Uterine blood flow indices, antinuclear autoantibodies and unexplained recurrent miscarriage

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Relationship between uterine natural killer cells and unexplained repeated miscarriage

OBJECTIVE

To evaluate the relation between uterine killer (uK) cells and unexplained repeated miscarriage (RM).

MATERIAL AND METHODS

Eighty women with unexplained repeated miscarriage and missed miscarriage of current pregnancy were studied. Fetal viability and gestational age of the current pregnancy were confirmed by ultrasound, followed by suction evacuation to collect abortion specimens and uterine wall curettage to collect decidua specimens. Abortion specimens were collected for long-term monolayer cell culture and subsequent chromosome analysis using conventional G-banding. Decidua specimens were subjected to immunohistochemical staining using monoclonal antibodies specific to CD56+ and CD16+ expressed by uK cells.

RESULTS

CD56+ CD16+ uK cells were found in 85% [68/80] of the studied decidua specimens of women with unexplained repeated miscarriage; 88.5% [54/61] had normal abortion karyotyping and 73.7% [14/19] had abnormal abortion karyotyping. Moreover, 73.75% [59/80] of the studied women with a past history of early miscarriage had CD56+ CD16+ uK cells in their decidua specimens, and 66.25% [53/80] of studied women with a past history of late miscarriage had CD56+ CD16+ uK cells in their decidua specimens; the association between early and late miscarriage and CD56+ CD16+ uK cells in decidua specimens was significant.

CONCLUSION

CD56+CD16+ uK cells were predominant in the decidua specimens of the studied women with repeated miscarriage. A significant association was found between the presence of CD56+ CD16+ uK cells in the studied decidua specimens and unexplained repeated miscarriage.

Genetic association between FXIII and β-fibrinogen genes and women with recurrent spontaneous abortion: a meta- analysis

BACKGROUND

FXIII Val34Leu (rs5985) and β-fibrinogen -455G/A (rs1800790) genotypes have been reported to be associated with recurrent spontaneous abortion (RSA). However, this topic is controversial. This study aimed to explore whether FXIII Val34Leu or β-fibrinogen -455G/A gene polymorphisms are related to RSA.

METHODS

In this analysis, PubMed, HuGENet and Chinese National Knowledge Infrastructure (CNKI) databases were reviewed. Four models including the dominant model (Val/Val+Val/Leu vs. Leu/Leu), recessive model (Val/Val vs Val/Leu + Leu/Leu), co-dominant model (Val/Val vs. Val/Leu, Val/Val vs. Leu/Leu) and per-allele analysis (Val vs. Leu) were applied. The odds ratio (OR) with 95% confidence interval (CI) was used to assess the association between RSA and FXIII Val34Leu and β-fibrinogen -455G/A polymorphisms.

RESULTS

Nine studies with 10 sets of data were included according to the inclusion criterion. A positive association was detected in the pooled results for the dominant model (Val/Val+Val/Leu vs. Leu/Leu; OR = 0.417, 95% CI: 0.180-0.965, I(2) = 45.60%) and co-dominant model (Val/Val vs. Val/Leu; OR = 0.638, 95% CI: 0.452-0.899, I(2) = 36.40%) for FXIII Val34Leu polymorphisms. However, no statistically significant association between β-fibrinogen -455G/A polymorphisms and RSA was detected in the four different models, including the Asian and Caucasian subgroup analyses.

CONCLUSIONS

Our meta-analysis demonstrates that the FXIII Val34Leu polymorphism has a close association with RSA and women who carry the Val allele for the FXIII Val34Leu polymorphism could have a protective effect against RSA. However, no association is detected between β-fibrinogen -455G/A polymorphisms and the risk of RSA. Future well-designed studies are needed to confirm these results.

Myeloid derived suppressor cells are present at high frequency in neonates and suppress in vitro T cell responses

Over 4 million infants die each year from infections, many of which are vaccine-preventable. Young infants respond relatively poorly to many infections and vaccines, but the basis of reduced immunity in infants is ill defined. We sought to investigate whether myeloid-derived suppressor cells (MDSC) represent one potential impediment to protective immunity in early life, which may help inform strategies for effective vaccination prior to pathogen exposure. We enrolled healthy neonates and children in the first 2 years of life along with healthy adult controls to examine the frequency and function of MDSC, a cell population able to potently suppress T cell responses. We found that MDSC, which are rarely seen in healthy adults, are present in high numbers in neonates and their frequency rapidly decreases during the first months of life. We determined that these neonatal MDSC are of granulocytic origin (G-MDSC), and suppress both CD4+ and CD8+ T cell proliferative responses in a contact-dependent manner and gamma interferon production. Understanding the role G-MDSC play in infant immunity could improve vaccine responsiveness in newborns and reduce mortality due to early-life infections.

Immunomodulation in recurrent miscarriage

There are many etiological factors responsible for recurrent abortions. However, no explanation can be identified in approximately 40-50 % of women with recurrent miscarriage (RM). Several studies demonstrated that successful pregnancy is dependant on shifting of maternal immune response from (proinflammatory) Th1 toward (anti-inflammatory) Th2 phenotypes. It was suggested that unexplained RM might be due to immunologic factors. Recently, there is improved understanding regarding the role of the different immune cells and proteins that are important at each stage of a normal pregnancy. Various immune-based therapies with variable clinical evidences have been reported in women with RM with variable efficacy. Still there is lack of information about the mode of action and possible adverse effects of the treatment and a reliable marker for patient selection for immunopotentiation. Adequately powered placebo-controlled studies are required to study and treat couples with the so-called idiopathic recurrent miscarriage.

Combined oral prednisolone and heparin versus heparin: the effect on peripheral NK cells and clinical outcome in patients with unexplained recurrent miscarriage. A double-blind placebo randomized controlled trial

Purpose

To evaluate the efficacy of the use of oral Prednisolone and heparin versus the use of heparin alone in treatment of patients with unexplained recurrent miscarriage.

Methodology

The study was a double-blind placebo randomized control trial conducted on 160 patients with unexplained recurrent miscarriage. Patients recruited were randomized into two groups. The first group received oral Prednisolone in addition to low dose aspirin and heparin, while the other group received a placebo in addition to low dose aspirin and heparin. A peripheral venous blood sample was taken from all included patients before starting treatment and collected in heparinized tubes. Natural Killer (NK) cells were checked in each sample and then re-checked in another sample at 20 weeks of gestation.

Results

We found that in the prednisolone group, 70.3 % of women had successful outcome (defined as an ongoing pregnancy beyond 20 weeks gestation), while 29.7 % miscarried before this gestation. On the contrary, among women in the placebo group, 9.2 % had successful outcome while 90.8 % miscarried before 20 weeks, which was statistically significant. On the other hand, we found that there were no significant paired differences between initial serum levels of the NK cells markers CD16 and CD56 and their levels at 20 weeks gestation in both groups.

Conclusion

The addition of prednisolone to heparin and low dose aspirin might be beneficial in patients with unexplained recurrent miscarriage, and this effect might be due to a suppressive effect of steroids on the peripheral CD16 NK cells concentration.

CD4+CD25+FoxP3+ regulatory T cells and cytokines interact with estradiol in cases of missed abortion

The aim of this study was to examine the interaction of estradiol (E2) with CD4⁺CD25⁺FoxP3⁺ regulatory T (Treg) cells and cytokines in cases of missed abortion (MA). The peripheral blood lymphocytes from patients with MA and controls (normal pregnancy and non-pregnant females) were isolated from the blood by Ficoll density gradient centrifugation. CD4⁺CD25⁺ Treg cells were isolated from peripheral blood mononuclear cells (PBMCs). The frequencies of CD4⁺CD25⁺FoxP3⁺ Treg cells and mRNA expression of transcription factor forkhead box protein 3 (FoxP3) in the peripheral blood of MA (n=33), normal pregnancy (n=33) and non-pregnant females (n=27) were determined by intracellular three-color flow cytometry and quantitative polymerase chain reaction (qPCR), respectively. The serum levels of interferon-γ (IFN-γ) and interleukin-4 (IL-4) were measured by enzyme-linked immunosorbent assay (ELISA) and a chemiluminescent immunoassay was used to examine the serum E2 levels. It was observed that the percentage of Foxp3⁺ T cells in the peripheral blood of patients with MA were lower compared with those in the normal pregnancy and healthy non-pregnant controls. The results demonstrated that MA patients exhibited decreased levels of a peripheral Th2-related cytokine (IL-4) and E2. Furthermore, the low levels of CD4⁺CD25⁺Foxp3⁺ T cells and IL-4 correlated positively with serum concentrations of E2. The data indicated that maternal immunological changes may reverse maternal tolerance in MA, and this phenomenon may be due to the interaction of E2 with CD4⁺CD25⁺Foxp3⁺ T cells and cytokines in MA.

Natural killer cells and their activation status in normal pregnancy

Increased peripheral blood-activated NK cell counts are associated with increased risk of miscarriage and failed in vitro fertilization treatment. However, assessment of activated peripheral NK cells in normal and pathological pregnancies beyond implantation and early miscarriage has not been described. Total CD69 expressing NK cells counts were measured by flow cytometry in healthy women with singleton pregnancies, including 45 at 11⁺⁶–13⁺⁶ weeks' gestation, 46 at 20⁺⁰–22⁺⁴ weeks, and 42 at 31⁺⁶–33⁺⁵ weeks. The number of peripheral blood NK cells decreased, whereas the percentage of activated CD69 expressing NK cells increased from the first to the third trimester of pregnancy. This study shows the course of peripheral blood NK cells and activated CD69 expressing NK cells in uncomplicated nulliparous singleton pregnancies. This is a first step in understanding their implication in pathological pregnancies.

Pro-inflammatory cytokine-stimulated first trimester decidual cells enhance macrophage-induced apoptosis of extravillous trophoblasts

OBJECTIVE

As human blastocyst-derived extravillous trophoblasts (EVTs) invade the early decidua, they are positioned to interact with immune cells and resident decidual cells, and remodel spiral arteries into high capacity vessels that increase blood flow to the developing fetal-placental unit. Shallow EVT invasion elicits incomplete vascular transformation and reduces uteroplacental blood flow that presages adverse pregnancy outcomes. Excess macrophages in the decidua induce EVT apoptosis via tumor necrosis factor-alpha (TNF-α) secretion. Our previous observation that pro-inflammatory cytokines enhance neutrophil and macrophage activator granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in first trimester decidual cells is now extended to include: (1) the specific macrophage activator M-CSF; (2) macrophage activation and subsequent enhancement of EVT apoptosis by both GM-CSF and M-CSF.

STUDY DESIGN

Quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay assessed M-CSF expression in first trimester decidual cells incubated with interleukin-1 beta (IL-1β) or TNF-α. Peripheral monocyte-derived macrophages pre-incubated with conditioned media from decidual cell cultures were co-cultured with a first trimester EVT cell line, HTR-8/SVneo cells. Macrophage activation was examined and EVT apoptosis evaluated by DNA fragmentation, caspase activation and cell membrane asymmetry.

RESULTS

IL-1β or TNF-α significantly enhanced M-CSF expression in first trimester decidual cells. The conditioned media from these cultures activates macrophages, which promote caspase 3/7-dependent EVT apoptosis with antibodies against GM-CSF or M-CSF blocking this effect.

CONCLUSIONS

Pro-inflammatory cytokines increases synthesis of M-CSF in first trimester decidual cells. Both GM-CSF and M-CSF activate macrophages, which initiate caspase-dependent EVT apoptosis.

Selective inhibition and augmentation of alternative macrophage activation by progesterone

Progesterone is the female sex hormone necessary for the maintenance of pregnancy, and is known to modulate macrophage activation. However, studies have concentrated exclusively on the ability of progesterone to negatively regulate the innate and classical pathways of activation, associated with nitric oxide (NO) and interleukin (IL)-12 production. Our aim was to examine the ability of progesterone to modulate alternative macrophage activation. Bone marrow cells were isolated and differentiated from male BALB/c mice, exposed to varying concentrations of progesterone and stimulated with lipopolysaccharide (LPS) (innate activation), IL-4 (alternative activation) or LPS in combination with IL-4. Our present study demonstrates that progesterone not only down-regulates inducible nitric oxide synthase 2 (iNOS) activity in macrophages but also arginase activity, in a dose-dependent manner, independent of the stimuli, whether it is induced by LPS (innate activation), IL-4 (alternative activation) or LPS in combination with IL-4. The ability of progesterone to down-modulate IL-4-induced cell surface expression of the mannose receptor further suggested a negative regulation of alternative macrophage activation by this hormone. Analysis of mRNA expression, by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), of genes associated with innate and alternative macrophage activation revealed that progesterone down-regulated LPS-induced macrophage nos2, argI and p40 (IL-12/IL-23) expression and IL-4-induced argI, mrc-1 and fizz1 expression. However, progesterone up-regulated IL-4-induced macrophage expression of ym1, while dectin-1 expression remained unaltered. Following treatment of macrophages with LPS and IL-4 in combination a similar pattern was observed, with the exception that progesterone up-regulated macrophage expression of fizz1 as well as ym1 and did not modify mrc-1 expression. Our data demonstrate for the first time that a hormone has the ability to regulate selectively the expression of different genes associated with alternative macrophage activation.