The Uterine Immune Profile May Help Women With Repeated Unexplained Embryo Implantation Failure After In Vitro Fertilization

Effects of intralipid infusions on anti-trophoblast antibody (ATAb)-activities in patients with recurrent pregnancy loss: An observational report

PROBLEM

Some studies suggest intravenous intralipid infusions (IVIL) to be effective in the treatment of immune-mediated pregnancy failure. To this date it remains to be established, how IVIL might protect pregnancy and therefore a specific subgroup of RPL patients that might benefit from IVIL has not been defined. Anti-trophoblast antibodies (ATAb) have been associated with RPL and appear to mediate immune pathology. We have shown, that ATAb in vitro decrease HCG- and progesterone production pointing to a mechanism how ATAb interfere with normal pregnancies. We have measured ATAb-activities in patients undergoing off label IVIL-treatment.

METHOD OF STUDY

Ten RPL-patients with positive ATAb, determined by using the choriocarcinoma cellline JEG-3 and flow cytometry as described before, and otherwise unexplained RPL, received off-label IVIL during pregnancy. Two ATAb-positive RPL patients preferred expectant management. In addition, ATAb-activity was studied in pregnancies of two healthy ATAb-negative volunteers without miscarriages.

RESULTS

In RPL patients receiving IVIL, relative ATAb-activity decreased from an average of 56.8±17.0% to 20.8±11.0% (P < .001). The two RPL-patients without IVIL, aborted at 6+3gw and 7+4gw and embryonic genetic testing revealed euploid karyotypes. During pregnancies of the two healthy ATAb-negative individuals, ATAb-activities remained negative (16±9.8%) without significant changes (P = .22). Nine of the 10 pregnancies receiving IVIL proceeded uneventful with healthy newborns ≥37gw. One patient receiving IVIL aborted at 7+6gw and embryonic genetic-testing revealed a trisomy 16. No specific side effects concerning IVIL were noted.

CONCLUSIONS

Intralipid preparations during pregnancies of ATAb-positive RPL-patients significantly reduce ATAb-activities and this may indicate a therapeutic mechanism of IVIL.

Role of adipokines in embryo implantation

Embryo implantation is a complex process in which multiple molecules acting together under strict regulation. Studies showed the production of various adipokines and their receptors in the embryo and uterus, where they can influence the maternal-fetal transmission of metabolites and embryo implantation. Therefore, these cytokines have opened a novel area of study in the field of embryo-maternal crosstalk during early pregnancy. In this respect, the involvement of adipokines has been widely reported in the regulation of both physiological and pathological aspects of the implantation process. However, the information about the role of some recently identified adipokines is limited. This review aims to highlight the role of various adipokines in embryo-maternal interactions, endometrial receptivity, and embryo implantation, as well as the underlying molecular mechanisms.

Uterine natural killer cell biology and role in early pregnancy establishment and outcomes

Objective

While immune cells were originally thought to only play a role in maternal tolerance of the semiallogenic fetus, an active role in pregnancy establishment is becoming increasingly apparent. Uterine natural killer (uNK) cells are of specific interest because of their cyclic increase in number during the window of implantation. As a distinct entity from their peripheral blood counterparts, understanding the biology and function of uNK cells will provide the framework for understanding their role in early pregnancy establishment and adverse pregnancy outcomes.

Evidence Review

This review discusses unique uNK cell characteristics and presents clinical implications resulting from their dysfunction. We also systematically present existing knowledge about uNK cell function in three processes critical for successful human embryo implantation and placentation: stromal cell decidualization, spiral artery remodeling, and extravillous trophoblast invasion. Finally, we review the features of uNK cells that could help guide future investigations.

Results

It is clear the uNK cells are intimately involved in multiple facets of early pregnancy. This is accomplished directly, through the secretion of factors that regulate stromal cells and trophoblast function; and indirectly, via interaction with other maternal cell types present at the maternal-fetal interface. Current work also suggests that uNK cells are a heterogenous population, with subsets that potentially accomplish different functions.

Conclusion

Establishment of pregnancy through successful embryo implantation and placentation requires crosstalk between multiple maternal cell types and invading fetal trophoblast cells. Defects in this process have been associated with multiple adverse perinatal outcomes including hypertensive disorders of pregnancy, placenta accreta, and recurrent miscarriage though the mechanism underlying development of these defects remain unclear. Abnormalities in NK cell number and function which would disrupt physiological maternal-fetal crosstalk, could play a critical role in abnormal implantation and placentation. It is therefore imperative to dissect the unique physiological role of uNK cells in pregnancy and use this knowledge to inform clinical practice by determining how uNK cell dysfunction could lead to reproductive failure.

Efficacy of Intrauterine Perfusion of Cyclosporin A for Intractable Recurrent Spontaneous Abortion Patients With Endometrial Alloimmune Disorders: A Randomized Controlled Trial

Objective

To explore the therapeutic efficacy of intrauterine perfusion of cyclosporin A (CsA) in intractable recurrent spontaneous abortion (RSA) patients with endometrial alloimmune dysfunction.

Methods

This is a randomized controlled trial (RCT) of patients with intractable RSA with endometrial alloimmune disorders. A total of 201 women were enrolled, all of whom had at least 3 serial abortions and endometrial alloimmune dysfunction. Participants were randomly assigned to two groups. The CsA group (n = 101) received intrauterine infusion of 250 mg CsA on the 3rd and 7th days after menstruation for 2 menstrual cycles, while the placebo group (n = 100) received placebo. The birth of healthy, deformity-free babies was the main study outcome.

Results

In total, 75 (74.26%) women in the CsA group and 59 (59.00%) women in the placebo group gave birth to healthy babies [P = 0.01, OR = 2.01; 95% CI (1.10∼3.65)]. Compared to the placebo group, the CsA group had dramatically lower endometrial CD56⁺ cell and CD57⁺ cell concentrations at the luteal phase of the second menstrual cycle (P < 0.05).

Conclusion

Intrauterine perfusion of CsA was confirmed to be a promising approach for the treatment of intractable alloimmune RSA.

Role of miRNAs in Normal Endometrium and in Endometrial Disorders: Comprehensive Review

The molecular responses to hormonal stimuli in the endometrium are modulated at the transcriptional and post-transcriptional stages. Any imbalance in cellular and molecular endometrial homeostasis may lead to gynecological disorders. MicroRNAs (miRNAs) are involved in a wide variety of physiological mechanisms and their expression patterns in the endometrium are currently attracting a lot of interest. miRNA regulation could be hormone dependent. Conversely, miRNAs could regulate the action of sexual hormones. Modifications to miRNA expression in pathological situations could either be a cause or a result of the existing pathology. The complexity of miRNA actions and the diversity of signaling pathways controlled by numerous miRNAs require rigorous analysis and findings need to be interpreted with caution. Alteration of miRNA expression in women with endometriosis has been reported. Thus, a potential diagnostic test supported by a specific miRNA signature could contribute to early diagnosis and a change in the therapeutic paradigm. Similarly, specific miRNA profile signatures are expected for RIF and endometrial cancer, with direct implications for associated therapies for RIF and adjuvant therapies for endometrial cancer. Advances in targeted therapies based on the regulation of miRNA expression are under evaluation.

Recurrent implantation failure: how common is it?

PURPOSE OF REVIEW

To clarify a lingering issue, the true incidence of repeated implantation failures (RIF) in women undergoing successive frozen euploid single embryo transfers (FE-SET).

RECENT FINDINGS

As not all Assisted reproductive techinique (ART) attempts are crowned by success, it has been questioned since incept of ART whether failures resulted from an embryonic or endometrial cause. RIF has received no precise definition but a trend has existed toward setting a more stringent definition, as reproductive biology has become more effective and ART success rates improved. No scientific society has yet convened on a universally accepted definition. The advent of effective and well tolerated pregestational testing of embryos for aneuploidy (PGT-A) has allowed to not transfer aneuploid embryos, which are bound not to succeed. This, therefore, justify revisiting the concept of RIF when only euploid embryos are transferred.

SUMMARY

Contrary to lingering beliefs, the results of our study indicate that RIF following three successive euploid embryo transfers in a morphologically normal endometrium is a rare occurrence (<5%). This supports the concept that ART failures mainly result from embryonic causes. Our data also propose a new - functional - definition of RIF being an ART failure following 3 successive FE-SET attempts. Our findings, therefore seriously question the soundness of prescribing the often complex and expensive endometrial testing procedures that largely publicized for treating RIF.

Impaired myeloid-derived suppressor cells are associated with recurrent implantation failure: A case-control study

BACKGROUND

Studies have reported that myeloid-derived suppressor cells (MDSCs) contribute to maintain pregnancy. The aim of this case-control study was to test whether there is a dysregulation of peripheral MDSCs in recurrent implantation failure (RIF).

METHODS

26 RIF patients and 30 controls were recruited. Flow cytometry was applied to characterize polymorphonuclear (PMN)-MDSCs, monocytic-MDSCs (M-MDSCs), effector T cells (Teffs) and regulatory T cells (Tregs) in blood. ELISA was used to define MDSCs correlative cytokines and chemokines in serum from all patients.

RESULTS

Compared with controls, RIF patients showed significant reductions of blood PMN-MDSCs, M-MDSCs, Tregs and NO production by PMN-MDSCs, whereas the expression of ζ chain on CD4+T cell receptor (TCR) and CD8+TCR displayed a remarkable upregulation in RIF patients. Moreover, RIF patients presented a lower concentration of serum chemokine (C-C motif) ligand (CCL) 5 and transforming growth factor (TGF)-β than those from controls. Furthermore, the level of TCR ζ chain on CD4+ and CD8+ Teffs was negatively correlated not only with the percentage of PMN-MDSCs, but also with the amount of NO produced by PMN-MDSCs. The frequency of PMN-MDSCs had positive correlations with the concentration of CCL5 and TGF-β.

CONCLUSIONS

This study indicated that the dysregulation of MDSCs might impair maternal-fetal immune balance thus resulting in RIF.

Placenta-Derived Exosomes as a Modulator in Maternal Immune Tolerance During Pregnancy

Exosomes are a subset of extracellular vesicles with an average diameter of ~100nm. Exosomes are released by all cells through an endosome-dependent pathway and carry nucleic acids, proteins, lipids, cytokines and metabolites, mirroring the state of the originating cells. The function of exosomes has been implicated in various reproduction processes, such as embryo development, implantation, decidualization and placentation. Placenta-derived exosomes (pEXO) can be detected in the maternal blood as early as 6 weeks after conception and their levels increase with gestational age. Importantly, alternations in the molecular signatures of pEXO are observed in pregnancy-related complications. Thus, these differentially expressed molecules could be the potential biomarkers for diagnosis of the pregnancy-associated diseases. Recent studies have demonstrated that pEXO play a key role in the establishment of maternal immune tolerance, which is critical for a successful pregnancy. To gain a better understanding of the underlying mechanism, we highlighted the advanced studies of pEXO on immune cells in pregnancy.

Unexplained recurrent miscarriages: predictive value of immune biomarkers and immunomodulatory therapies for live birth

INTRODUCTION

Recurrent miscarriages are defined as three or more early miscarriages before 12 weeks of gestation. The aim of this study was to describe a cohort of women with unexplained recurrent miscarriages, evaluate several potential biomarkers of immune origin, and describe the outcome of pregnancies under immunomodulatory therapies.

METHODS

Women having a history of at least 3 early miscarriages without any etiology were recruited from 3 university hospitals.

RESULTS

Among 101 women with recurrent miscarriages, overall, 652 pregnancies have been included in the analysis. Women which experienced miscarriages were older (33.3 ± 5.4 versus 31.9 ± 6.7; p = 0.03), with history of more pregnancies (4 (2-6) versus 3.5 (1-5.75); p 0.0008), and less frequently the same partner (406 (74%) versus 79 (86%); p=0.01). There was no difference in the level and frequencies of biomarkers of immune origin (NK, lymphocyte, gamma globulins and blood cytokine levels and endometrial uNK activation status), except the higher rates of positive antinuclear antibodies in women with live birth (12 (13%) versus 36 (7%); p=0.03). Among the 652 pregnancies, 215 (33%) have been treated and received either aspirin/low weighted molecular heparin (LMWH) and/or combined to different lines of immunomodulatory treatment. Patients with pregnancy under treatment had a significantly higher rate of cumulative live birth rate than those with untreated ones (43.0% vs 34.8%; p = 0.04). When compared to patients with untreated pregnancies, patients with steroids during the pregnancy had twice more chances to obtain live birth (OR 2.0, CI95% 1.1 - 3.7, p = 0.02).

CONCLUSIONS

Unexplained recurrent miscarriages could have improved obstetrical outcome under immunomodulatory therapies and in particular steroids.

The Endometrial Immune Profiling May Positively Affect the Management of Recurrent Pregnancy Loss

Introduction

The endometrial immune profiling is an innovative approach based on the analysis of the local immune reaction occurring in the endometrium at the time of the embryo implantation. By documenting the local immune activation during the period of uterine receptivity, we aim to detect and correct potential imbalances before and at the very beginning of placentation. The main objective of the study was to analyze in women with a history of repeated pregnancy loss (RPL) the association of personalized strategies based on immune dysregulations with live birth rates. The secondary objective was to highlight the main prognostic factors for live births.

Methods

This is an observational retrospective analysis of 104 patients with RPL, included between January 2012 and December 2019. Inclusion criteria included a spontaneous fertility with at least three miscarriages, an assessment including a three-dimension ultrasound scan, an endometrial biopsy for uterine immune profiling and a follow-up over at least 6 months with personalized care if indicated after the complete assessment. We defined as a success if the patients had a live birth after the suggested plan, as a failure if the patient either did not get pregnant or experienced a new miscarriage after the targeted therapies.

Results

Uterine immune profiling was the only exploration to be significantly associated with a higher live birth rate (LBR) if a dysregulation was identified and treated accordingly (55% vs 45%, p=0.01). On the contrary, an absence of local dysregulation (resulting in an apparently balanced immune environment) was associated with a higher risk of a new miscarriage, suggesting that the cause inducing RPL still needed to be identified. Independently of age and AMH level, dysregulated immune profile is significatively associated with 3 times higher LBR than a non-deregulated profile (OR=3.4 CI 95%1.27-9.84) or five times in case of an overactive profile treated by immunotherapy (OR=5 CI 95% 1.65-16.5). The usage of ART was significantly associated with lower LBR regardless of the presence of a subfertility factor (p=0.012). Personalization of medical care using natural cycle or simple hormonal stimulation is associated with a significantly higher LBR than personalization including ART treatments regardless of maternal age and AMH level (OR= 2.9 CI 95% 1.03-8.88).

Conclusion

Our study suggests that some endometrial immune profiles with targeted management of RPL are associated with a higher rate of LBR. ART may be negatively associated with LBR.

Approaches to Improve Endometrial Receptivity in Case of Repeated Implantation Failures

Repeated implantation failures are a constant challenge in reproductive medicine with a significant impact both on health providers and on infertile couples. Several approaches have been proposed so far as effective; however, accumulative data have clarified that most of the treatment options do not have the evidence base for a generalized application to be suggested by the relevant societies. Implantation failures are attributed to either poor quality embryos or to defected endometrial receptivity. The current review aims to summarize in a systematic way all the new trends in managing RIF via interference with endometrial receptivity. The authors focus mainly, but not exclusively, on endometrial injury prior to embryo transfer and endometrial priming with autologous cells or biological agents. To this direction, a systematic search of the Pubmed database has been conducted taking into account the emerged evidence of the last two decades. All the suggested interventions are herein presented and analyzed in terms of reproductive outcomes. It is evident that properly powered and designed randomized trials are needed to support a new standard approach in RIF treatment that will safely be incorporated in national and international guidelines.

Lymphocyte immunotherapy in recurrent miscarriage and recurrent implantation failure

PROBLEM

Lymphocyte immunotherapy (LIT) emerged in the early 1980s as a new therapeutic proposal for couples with a history of recurrent miscarriages (RM). However, in the early 2000s, the effectiveness of LIT was questioned. Recently, meta-analyses have observed the effectiveness and safety of LIT in treating couples with RM. Some studies evaluated the use of LIT in recurrent implantation failure (RIF) in in vitro fertilization cycles.

METHODS

This systematic and narrative review evaluated the data available in the literature regarding the efficacy and safety of the use of LIT. Searches in PubMed/Medline, Embase, and Cochrane Library databases were conducted, using the following keywords: "recurrent miscarriage," "lymphocyte immunotherapy," and "recurrent implantation failure".

RESULTS

This review describes the historical aspects of LIT and discusses its protocols, mechanisms of action, side effects, complications, and current evidence of the effectiveness in cases of reproductive failure. It also discusses the use of LIT during the COVID-19 pandemic and new immunological therapies.

CONCLUSION

In the vast majority of studies, the use of LIT for RM couples has shown an improvement in pregnancy outcomes. The most of the current studies that support the evidence are quasi-experimental, with few randomized, double-blind studies (Level of evidence III). However, the current evidence are not convincing for the use of LIT in RIF patients.

Decidualization score identifies an endometrial dysregulation in samples from women with recurrent pregnancy losses and unexplained infertility

OBJECTIVE

To study decidualization-associated endometrial factors.

DESIGN

Retrospective cohort study to compare endometrial gene expression patterns in women experiencing reproductive failure including recurrent pregnancy loss or unexplained infertility versus fertile controls.

SETTING

University Reproductive Medicine Center.

PATIENTS

Women experiencing recurrent reproductive failure including recurrent pregnancy loss or unexplained infertility (n = 42) and fertile controls (n = 18).

INTERVENTIONS

Endometrial biopsy samples were analyzed with targeted ribonucleic acid sequencing via next-generation sequencing.

MAIN OUTCOME MEASURES

The primary end point measurements were the expression of genes important for endometrial transformation during decidualization measured singly and in a combined/cumulative score approach. The secondary end point measurements were receiver operating curve analysis and comparisons between the specific biomarkers.

RESULTS

The comparison revealed differential expression of factors associated with decidualization, tissue homeostasis, and immune regulation: FOXO1, GZMB, IL15, SCNN1A, SGK1, and SLC2A1. A combined evaluation of these 6 signature factors was designated as a decidualization score in which the maximal score was "6" and the minimal was "0". Among controls, 89% of the samples had a score ≥5 and 11% had a score of "4". A total of 76% of samples in the patient group had scores ≤4 and 19% had the lowest score of "0". A decidualization score <4 provided evidence of abnormality in the decidualization process with a sensitivity of 76% (95% CI 61%-88%) and specificity of 89% (95% CI 65%-99%).

CONCLUSIONS

Decidualization scoring can determine whether the endometrial molecular profile is implantation-friendly. Further validation of this testing approach is necessary to determine a particular patient population in whom it could be used for selecting patients that require therapeutic actions to improve endometrial conditions prior to the in vitro fertilization procedure.

Conventional microscopy versus digital image analysis for histopathologic evaluation of immune cells in the endometrium

In the search for a reliable biomarker able to diagnose immunological causes of infertility, uterine immune cells have been widely investigated. As a result, heterogeneous methods and cutoff values of what constitutes an aberrant number of immune cells have been reported, and a standardized method for quantification is needed. The objective of this study was to compare methods for quantification of immune cells visualized with immunohistochemistry in the endometrium of women in fertility treatment. Evaluation of the density of CD56⁺, CD16⁺ and CD163⁺ cells by conventional microscopy on a semiquantitative scale (low, medium and high) was compared to a continuous count using digital image analysis (DIA) reported as percentage positive cells out of the total number of stromal cells and number of positive cells per mm², respectively. We previously reported the CD56/CD16 ratio as a possible prognostic marker, and therefore the ratios of CD56/CD16 were compared using two different methods for selecting fields for counting with DIA: one method using principles of systematic random sampling, where glands were excluded, and one method analyzing large parts of the tissue including glands. A significant association between conventional microscopy and DIA was found when the semiquantitative scale was compared to medians of positive cells in CD56, CD16 and CD163, respectively, p < 0.001. A systematic significant difference in the ratios of CD56/CD16 was found when comparing the two methods for field selection, p < 0.001. To determine the possible use of these methods, more knowledge of the correlation to clinical outcome is warranted.

Endometrial preparation with etanercept increased embryo implantation and live birth rates in women suffering from recurrent implantation failure during IVF

Recurrent implantation failure (RIF),  defined as ≥3 failed in vitro fertilization (IVF) cycles with the accumulated transfer of at least five embryos, plague many infertile women. The exact cause is unknown; however, evidence supports the immune system, specifically the Tumor Necrosis Factor (TNF) pathway. Etanercept (a TNFα antagonist) has been shown to improve pregnancy rates in women with rheumatoid arthritis or endometriomas; therefore, this study aimed to determine the effectiveness of etanercept for IVF in RIF women. Eighty-three RIF women were recruited from the Ingenes Institute in Mexico City for this single-arm, prospective study. All patients underwent a similar IVF protocol and received etanercept (4 × 25 mg every 72 h) after endometrial preparation, if applicable, and at embryo transfer. IVF endpoints assessed were embryo implantation (h-βCG >10 mg/dL at Day 14), the presence of a gestational sac, live birth, and birth weight. All women reported no side-effects associated with the etanercept treatment. 75.9 % of the cohort achieved embryo implantation, 74.7 % developed gestational sacs, and the ongoing pregnancy/live birth rate was at 62.7 %. However, 56.7 % of the live births were preterm (<37 weeks) and 60.5 % of the births were underweight (<2500 g). When stratified by fresh or frozen cycles or by the ova source (patient versus donor), the results were not significantly different with respect to the implantation rate, formation of gestational sacs, and the live birth rate. Here, we showed that using etanercept during endometrial preparation improves IVF outcomes in RIF women.

Analysis of IVF/ICSI Outcomes in Endometriosis Patients With Recurrent Implantation Failure: Influence on Cumulative Live Birth Rate

OBJECTIVE

To study the influence of endometriosis activity on the pregnancy outcomes of patients with recurrent implantation failure (RIF) in in-vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) cycles. The pregnancy outcomes were compared between RIF patients with endometriosis who received treatment at different occasions to explore the appropriate treatment plan for these patients and to optimize the pregnancy-support strategies.

DESIGN

Ambispective cohort study.

METHODS

A total of 330 patients with endometriosis were enrolled from 2008 to 2018 and included 1043 IVF/ICSI cycles. All patients were diagnosed with RIF after IVF/ICSI. Patients were assigned to three subtypes according to different control states of endometriosis, including the untreated, early-treatment, and late-treatment groups. The clinical pregnancy rate, live birth rate, and cumulative live birth rate of endometriosis patients with RIF were the main outcomes; additionally, the fertilization rate, available embryonic rate, and high-quality embryonic rate were also compared.

RESULTS

The early-treatment and late-treatment groups showed higher cumulative live birth rate than the untreated group (early-treated 43.6% vs. late-treated 46.3% vs. untreated 27.7%, P<0.001), though patients in the two treatment groups had higher rates of adenomyosis and ovarian surgery. The two treatment group showed a better laboratory result than the untreated and especially, the early-treatment group. The untreated group (46.24%) had a lower IVF fertilization rate than the treated group (early-treated [64.40%] and late-treated [60.27%] (P<0.001). In addition, the rates of available embryos and high-quality embryos in the early-treated group were much higher those that in the untreated group (90.30% vs. 85.20%, 76.50% vs. 64.47%). Kaplan-Meier curve showed that patients in the untreated group needed a mean of 23.126 months to achieve one live birth; whereas those in the treated group needed a comparatively shorter duration (early-treated: 18.479 ± 0.882 months and late-treated: 14.183 ± 1.102 months, respectively).

CONCLUSION

Endometriosis has a negative influence on IVF/ICSI outcome. The control of endometriosis activity can result in a higher cumulative live birth rate in patients. It is necessary for endometriosis patients to receive medical treatment to achieve a better prognosis especially for those with RIF.

Haem oxygenases play a pivotal role in placental physiology and pathology

BACKGROUND

Haem oxygenases (HO) catabolise haem, which is the prosthetic group of numerous haemoproteins. Thus, multiple primary cellular pathways and functions rely on haem availability. HO exists in two isoforms, both expressed in the placenta, namely HO-1 and HO-2, the first being inducible. Haem oxygenases, particularly HO-1, have garnered specific interest in the field of physiological and pathological placental function. These enzymes mediate haem degradation by cleaving the alpha methene bridge to produce biliverdin, which is subsequently converted to bilirubin, carbon monoxide and iron. HO-1 has anti-inflammatory and antioxidant activities.

SEARCH METHODS

An initial literature analysis was performed using PubMed on 3 October 2018 using key terms such as 'haem oxygenase and pregnancy', 'haem oxygenase and placenta', 'HO-1 and pregnancy', 'HO-1 and placenta', 'HO and placenta', 'HO and pregnancy', 'genetic variant and HO', 'CO and pregnancy', 'CO and placenta', 'Bilirubin and pregnancy', 'Iron and pregnancy' and 'PPAR and Haem', selecting consensus conferences, recommendations, meta-analyses, practical recommendations and reviews. A second literature analysis was performed, including notable miscarriages, foetal loss and diabetes mellitus, on 20 December 2019. The three authors studied the publications independently to decipher whether they should be included in the manuscript.

OBJECTIVE AND RATIONALE

This review aimed to summarise current pieces of knowledge of haem oxygenase location, function and regulation in the placenta, either in healthy pregnancies or those associated with miscarriages and foetal loss, pre-eclampsia, foetal growth restriction and diabetes mellitus.

OUTCOMES

HO-1 exerts some protective effects on the placentation, probably by a combination of factors, including its interrelation with the PGC-1α/PPAR pathway and the sFlt1/PlGF balance, and through its primary metabolites, notably carbon monoxide and bilirubin. Its protective role has been highlighted in numerous pregnancy conditions, including pre-eclampsia, foetal growth restriction, gestational diabetes mellitus and miscarriages.

WIDER IMPLICATIONS

HO-1 is a crucial enzyme in physiological and pathological placentation. This protective enzyme is currently considered a potential therapeutic target in various pregnancy diseases.

Cytokines in embryonic secretome as potential markers for embryo selection

Despite performing certain morphological assessments for selecting the best embryo for transfer, the results have not been satisfactory. Given the global tendency for performing quick and noninvasive tests for embryo selection, great efforts have been made to discover the predictive biomarkers of embryo implantation potential. In recent years, many factors have been detected in embryo culture media as a major source of embryo secretions. Previous studies have evaluated cytokines, miRNAs, extracellular vesicles, and other factors such as leukemia inhibitory factor, colony-stimulating factor, reactive oxygen species, soluble human leukocyte antigen G, amino acids, and apolipoproteins in these media. Given the key role of cytokines in embryo implantation, these factors can be considered promising molecules for predicting the implantation success of assisted reproductive technology (ART). The present study was conducted to review embryo-secreted molecules as potential biomarkers for embryo selection in ART.

CBS and MAT2A improve methionine-mediated DNA synthesis through SAMTOR/mTORC1/S6K1/CAD pathway during embryo implantation

Objectives

Early pregnancy loss is a major clinical concern in animal and human reproduction, which is largely influenced by embryo implantation. The importance of methionine for embryo implantation is widely neglected.

Materials and methods

We performed a series of experiments with primiparous rats fed diets containing different levels of methionine during early pregnancy to investigate the role of methionine in embryonic implantation and pregnancy outcomes, and used them to perform in vivo metabolic assessments and in vitro uterine explant culture. In addition, through transcriptome analysis and silencing the expression of cystathionine β‐synthase (CBS, the key enzyme in transsulfuration pathway) and cell adhesion assay, we measured signalling within Ishikawa, pTr and JAR cells.

Results

We determined the relevance and underlying mechanism of methionine on embryo implantation. We showed that methionine deprivation sharply decreased embryo implantation sites, expression of CBS and transsulfuration pathway end products, which were reversed by maternal methionine supplementation during early pregnancy. Moreover, we found CBS improved methionine‐mediated cell proliferation and DNA synthesis by CBS inhibition or interference. In addition, transcriptome analysis also revealed that CBS influenced the signalling pathway‐associated cell proliferation and DNA synthesis, as well as a correlation between CBS and methionine adenosyltransferase 2A (MAT2A), implying that MAT2A was possibly involved in cell proliferation and DNA synthesis. Further analysis revealed that MAT2A influenced S‐adenosylmethionine receptor SAMTOR expression, and SAMTOR activated mTORC1 and its downstream S6K1 and CAD, ultimately enhancing DNA synthesis in the embryo and uterus.

Conclusions

Taken together, these studies demonstrate that CBS and MAT2A improve methionine‐mediated DNA synthesis through SAMTOR/mTORC1/S6K1/CAD pathway during embryo implantation.

Association of CD200 expression in paternal lymphocytes with female Th1/Th2 balance and pregnancy establishment at immunotherapy of recurrent spontaneous abortion

PROBLEM

We hypothesized that expression of transmembrane glycoprotein CD200 on paternal lymphocytes used for pre-gestational lymphocyte immunotherapy (LIT) of recurrent spontaneous abortion (RSA) can suppress the pro-inflammatory Th1-type immunity required for successful implantation. To reveal the association between CD200 expression, female immune background after LIT, and pregnancy establishment, we have performed this work.

METHOD OF STUDY

Pre-gestational alloimmunizations were given to 37 women using paternal peripheral blood leukocytes, combined with additional alloimmunizations in case of pregnancy. Lymphocyte phenotypes were determined by flow cytometry. Cytokines produced by mitogen-stimulated female peripheral blood cells were estimated by FlowCytomix™ technology.

RESULTS

We have shown that 78.4% (29/37) of women became pregnant within 12 menstrual cycles after pre-gestational LIT. Pregnancy establishment depends on the intensity of CD200 expression, which is significantly higher on the CD200⁺ lymphocytes administered to women who later did not achieve pregnancy (P < .05). The expression of CD200 negatively correlates with the ratios of Th1/Th2 cytokines produced by female peripheral blood cells (P < .05) and positively correlates with the frequency of female circulating regulatory T cells after LIT (P < .05). The ROC analysis showed that the intensity of CD200 expression and the Th1/Th2 ratios are the significant predictors of pregnancy establishment after pre-gestational LIT (P < .05 and P < .01, respectively).

CONCLUSION

Elevated CD200 expression on allogeneic lymphocytes most likely suppresses the pro-inflammatory Th1-type immunity needed for successful embryo implantation. Therefore, a personalized approach of LIT should be applied to avoid negative effects of such immunomodulation on pregnancy establishment.

Successful Pregnancy in a Case of Behçet's Disease after Treatment with Prednisolone

A 34-year-old woman (gravida 1, para 0) visited the Division of Reproductive Medicine/National Center for Child Health and Development due to infertility; she had also been suffering from incompletely treated genital ulcers and stomatitis for 10 years. This case was diagnosed as an incomplete-type Behçet's disease (BD) at the Department of Maternal-Fetal Biology/National Center for Child Health and Development. Since no apparent abnormality was found in the general infertility test, artificial insemination with the husband's semen (AIH) was performed for the patient with unexplained infertility, which failed. However, after treating BD with prednisolone, chronic inflammation (stomatitis and genital ulcer) and immunological abnormalities (Th2 and NK cell activity) improved, and conception was possible by AIH. Thus, prednisolone administration may have induced immune tolerance in the patient with BD, which may have contributed to the success of AIH.

Are different markers of endometrial receptivity telling us different things about endometrial function?

PROBLEM

To what extent do endocrine, immunological, gene expression and histological markers of endometrial receptivity correlate?

METHOD OF STUDY

Between November 2017 and September 2019, 121 women referred to a University Hospitals Fertility Clinic consented to inclusion in this cohort study. The women underwent timed endometrial biopsy followed by blood samples in a hormone-substituted cycle. Of these, 37 women had just started IVF treatment, and the remaining 84 had experienced recurrent implantation failure following IVF/ICSI. The hormone-substituted cycle consisted of initiation with oral oestradiol followed by addition of vaginal progesterone treatment for five full days. Endometrial biopsies were subject to histological examination, immune cell markers by immunohistochemistry (CD56⁺ , CD16⁺ , CD163⁺ , FoxP3) and gene expression microarray analyses with the endometrial receptivity array (ERA^® ) test (Igenomix). Plasma progesterone and oestradiol were measured on the day of biopsy.

RESULTS

CD56⁺ uterine natural killer (uNK) cell counts correlate with transcriptional markers of endometrial receptivity assessed by the ERA test. Endometrial maturation, receptivity and immunological markers were not correlated with mid-luteal blood plasma progesterone level. Mid-luteal serum oestradiol level correlated with markers of endometrial maturation and receptivity. The tests were carried out during a standard hormone substitution cycle, and the findings may not apply in the natural cycle.

CONCLUSION

CD56⁺ uNK cell counts and endometrial receptivity assessed by the ERA test appear to be linked. Mid-luteal progesterone levels were not correlated to the tested markers of endometrial receptivity. In contrast, mid-luteal oestradiol level was inversely related to markers of endometrial receptivity and maturation.

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

STUDY QUESTION

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

SUMMARY ANSWER

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

WHAT IS ALREADY KNOWN

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

STUDY DESIGN, SIZE, DURATION

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

PARTICIPANTS/MATERIALS, SETTING, METHODS

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

MAIN RESULTS AND THE ROLE OF CHANCE

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

LARGE SCALE DATA

Not applicable.

LIMITATIONS, REASONS FOR CAUTION

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

WIDER IMPLICATIONS OF THE FINDINGS

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

STUDY FUNDING/COMPETING INTEREST(S)

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

Assessing endometrial receptivity after recurrent implantation failure: a prospective controlled cohort study

RESEARCH QUESTION

What is the prevalence of disrupted markers of endometrial function among women experiencing recurrent implantation failure (RIF), and does the prevalence differ from a control cohort?

DESIGN

Prospective controlled cohort study. In total, 86 women with a history of RIF and 37 women starting their first fertility treatment were recruited for this study. Endometrial and blood profiling were carried out in a hormone-substituted cycle using oestradiol and progesterone. Endometrial biopsies were analysed by histology, immune cell profiling, and the endometrial receptivity array (ERA®) test (Igenomix, Valencia, Spain). The vaginal microbiome was analysed using a NGS-based technology (ArtPRED, Amsterdam, the Netherlands). Blood tests included oestradiol, progesterone, prolactin, thyroid-stimulating hormone, vitamin D and anti-phospholipid antibody levels.

RESULTS

Patients who had experienced RIF produced a range of test abnormalities. Compared with controls, women with RIF had a higher prevalence of chronic endometritis (24% versus 6%), a lower vitamin D level and a borderline lower progesterone level. Women who had experienced RIF had a more favourable vaginal microbiome compared with controls. Although the RIF cohort was older than the controls (mean age 33.8 years versus 30.2 years), no differences between the groups were observed in immune cell profiling and the ERA test.

CONCLUSION

These data demonstrate that a single test or treatment for the endometrial factor in RIF is unlikely to be clinically effective. Diagnosing the endometrium in women with RIF permits targeted rather than blind interventions. Relative vitamin D deficiency, lower mid-luteal progesterone and chronic endometritis are ready targets for treatment. Understanding the role and treatment of an unfavourable vaginal microbiome in RIF needs further investigation.

Recurrent implantation failure in IVF: A Canadian Fertility and Andrology Society Clinical Practice Guideline

Recurrent implantation failure (RIF) after IVF is a challenging topic for clinicians and can be a devastating reality for some patients with infertility. The purpose of this guideline from the Canadian Fertility and Andrology Society (CFAS) is to provide the most relevant evidence to date for the assessment and management of RIF. This guideline was developed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. This guideline recognizes the presence of heterogeneity in the definition of RIF. Recommendations are offered here on the investigation of RIF and management options that may increase the chance of a live birth.

Tacrolimus Improves the Implantation Rate in Patients with Elevated Th1/2 Helper Cell Ratio and Repeated Implantation Failure (RIF)

Introduction An abnormal endometrial immune response is involved in the pathogenesis of repeated implantation failure (RIF), so we investigated the effectiveness of tacrolimus treatment on the endometrium of RIF patients.

Materials and Methods Ten RIF patients with elevated T-helper 1/T-helper 2 (Th1/Th2) cell ratios were recruited into a clinical study. The expression of p53, leukemia inhibitory factor (LIF), interleukin (IL)-4, IL-10, IL-17, and interferon gamma (IFN-γ) in the endometrium of patients with and without tacrolimus treatment and the association of these factors with assisted reproductive technology (ART) outcomes were investigated.

Results Tacrolimus significantly increased the expression of LIF, IL-10, and IL-17 and decreased the expression of IL-4, IFN-γ, and the IFN-γ/IL-10 ratio in RIF patients. Tacrolimus treatment resulted in an implantation rate of 40%, a clinical pregnancy rate of 50%, and a live birth rate of 35% in RIF patients with elevated Th1/Th2 ratios who had previously failed to become pregnant despite at least three transfers of embryos. We also found a significant positive correlation between IL-10 levels and the implantation rate.

Conclusions Our findings suggest that RIF patients with a higher Th1/Th2 ratio could be candidates for tacrolimus therapy and that this immunosuppressive drug could be acting through upregulation of LIF, IL-10, and IL-17.

[Endometrial receptivity in assisted reproductive techniques: An aspect to investigate in embryo implantation failure]

Infertility affects between 8 and 12% of reproductive-age couples worldwide. Despite improvements in assisted reproductive techniques (ART), live birth rates are still limited. In clinical practice, imaging and microscopy are currently widely used, but their diagnostic effectiveness remains limited. In research, the emergence of innovative techniques named OMICS would improve the identification of the implantation window, while progressing in the understanding of the pathophysiological mechanisms involved in embryo implantation failures. To date, transcriptomic analysis seems to be the most promising approach in clinical research. The objective of this review is to present the results obtained with the different approaches available in clinical practice and in research to assess endometrial receptivity in patients undergoing ART.

The effect of intralipid on pregnancy outcomes in women with previous implantation failure in in vitro fertilization/intracytoplasmic sperm injection cycles: A systematic review and meta-analysis

Several recent studies have investigated the relationship between intravenous intralipid and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes in women with previous implantation failure. We conducted a systematic review and meta-analysis to evaluate the effects of intravenous intralipid on pregnancy outcomes in women with previous implantation failure. Ovid MEDLINE, the Cochrane Library, Embase and ClinicalTrials.gov were searched up to August 5th, 2019. Randomized controlled trials comparing intravenous intralipid with placebo or no treatment during IVF/ICSI cycles in women with at least one implantation failure were included. Results were presented as risk ratio (RR) with 95 % confidence intervals (CIs). Four studies with 544 participants were included. Live birth rate was statistically higher among the groups of women who received intravenous intralipid (RR 1.98, 95 % CI 1.39-2.80, quality of evidence: low). Intralipid infusion could significantly improve clinical pregnancy rate (RR 1.74, 95 % CI 1.27-2.40, quality of evidence: low). When excluding two studies only published as conference abstracts, there were no significant differences in terms of live birth (RR 1.78, 95 % CI 0.95-3.34, heterogeneity: I² = 25.5 %, quality of evidence: low, Fig. 4A) and clinical pregnancy (RR 1.66, 95 % CI 0.90-3.08, heterogeneity: I² = 47.7 %, quality of evidence: low, Fig. 4B). Adverse events were reported to be rare, but three congenital anomalies were observed in women receiving intravenous intralipid. Administering intravenous intralipid during IVF/ICSI cycles may improve live birth and clinical pregnancy in women with previous implantation failure, such benefit is not significant excluding studies with high risk of bias in the analysis, more studies are needed to evaluate its efficacy and safety especially congenital malformations.

Intralipid therapy for unexplained recurrent miscarriage and implantation failure: Case-series and literature review

INTRODUCTION

In retrospective cohort study of women with unexplained recurrent implantation failure (RIF) and miscarriage (RM), we analyzed the efficacy and safety of intralipid therapy to obtain a live birth.

PATIENTS AND METHODS

Women with unexplained RM and/or RIF were included from 2015 to 2018 from three French university hospitals.

RESULTS

Among 187 women treated for unexplained recurrent miscarriages and implantation failures, 26 women with median age of 36 years (29-43) received intralipid therapy. Among these 26 women, 10 women with a median age of 33 years (31-40) had a history of spontaneous recurrent miscarriages, with a median of 5 (4-8) previous miscarriages. Live births occurred in 7 (70 %) pregnancies under intralipids and were significantly more frequent than in women with recurrent miscarriages who did not receive intralipid therapy (n = 20, p = 0.02). Age, number of previous miscarriages, and additional therapies did not significantly differ between the two groups. Among the 26 included women, 16 had a history of recurrent implantation failures, with median age of 37 years (29-43) and median 9.5 (3-19) embryo transfers. Clinical pregnancy occurred in 9 (56 %) women receiving intralipids after embryo transfers under intralipids among which 5 (55 %) resulted in a live birth. Comparing successful pregnancies under intralipids with those with fetal loss, no significant differences have been noted.

CONCLUSION

Intralipids could be an effective and safe therapy in women with unexplained recurrent miscarriages and infertility.

Pathophysiological Basis of Endometriosis-Linked Stress Associated with Pain and Infertility: A Conceptual Review

Women with endometriosis are often under stress due to the associated pain, infertility, inflammation-related and other comorbidities including cancer. Additionally, these women are also under stress due to taboos, myths, inter-personal troubles surrounding infertility and pain of the disease as well as due to frequent incidences of missed diagnosis and treatment recurrence. Often these women suffer from frustration and loss of valuable time in the prime phase of life. All these complexities integral to endometriosis posit a hyperstructure of integrative stress physiology with overt differentials in effective allostatic state in women with disease compared with disease-free women. In the present review, we aim to critically examine various aspects of pathophysiological basis of stress surrounding endometriosis with special emphasis on pain and subfertility that are known to affect the overall health and quality of life of women with the disease and promising pathophysiological basis for its effective management.

Endometrial Immune Profiling: A Method to Design Personalized Care in Assisted Reproductive Medicine

Objective: To assess the efficiency of the endometrial immune profiling as a method to design personalized care to enhance the pregnancy rate in a large heterogeneous infertile population. We hypothesized that some reproductive failures could be induced by a uterine immune dysregulation which could be identified and corrected with a targeted plan. Design: Prospective cohort study. Setting: Multicentric study. Intervention(s) and Main outcome measure(s): One thousand and seven hundred thirty-eight infertile patients had an immune profiling on a timed endometrial biopsy between 2012 and 2018. This test documented the absence or the presence of an endometrial immune dysregulation and identified its type. In case of dysregulation, a targeted personalized plan was suggested to the treating clinician aiming to supply the anomaly. One year after the test, the clinician was contacted to provide the outcome of the subsequent embryo transfer with the applied suggested plan. Result(s): After testing, 16.5% of the patients showed no endometrial immune dysregulation, 28% had a local immune under-activation, 45% had a local immune over-activation, and 10.5% had a mixed endometrial immune profile. In patients with a history of repeated implantation failures (RIF) or recurrent miscarriages (RM), the pregnancy rate was significantly higher if an endometrial dysregulation was found and the personalized plan applied, compared to the patients with an apparent balanced immune profile (respectively 37.7 and 56% vs. 26.9 and 24%, p < 0.001). In contrast, in good prognosis IVF (in vitro fertilization) subgroup and patients using donor eggs, this difference was not significant between dysregulated and balanced subgroups, but higher pregnancy rates were observed in absence of dysregulation. For patients with immune over-activation, pregnancy rates were significantly higher for patients who had a test of sensitivity, regarding the type of immunotherapy introduced, when compared to the ones who did not (51 vs. 39.9%, p = 0.012). Conclusion(s): Local endometrial immunity appears to be a new and important parameter able to influence the prognosis of pregnancy. Targeted medical care in case of local immune dysregulation resulted in significantly higher pregnancy rates in RIF and RM patients.

Endometrial stromal cell inflammatory phenotype during severe ovarian endometriosis as a cause of endometriosis-associated infertility

RESEARCH QUESTION

Do endometrial stromal cells from primary infertile patients with severe ovarian endometriosis display differential secretory profiles of inflammation-associated cytokines during the implantation window that may cause infertility?

DESIGN

Forty-eight cytokines were measured in conditioned medium of isolated endometrial stromal cells obtained from primary infertile patients without endometriosis (control group, n = 12) or with stage IV ovarian endometriosis (ovarian endometriosis group, n = 14) using multiplex assays. Key cytokines showing differential secretory profiles were validated using Western immunoblotting. Cellular phenotypic validation was carried out in vitro by comparing proliferation and migration capacity between control (n = 6) and ovarian endometriosis (n = 7) groups.

RESULTS

CCL3, CCL4, CCL5, CXCL10, FGF2, IFNG, IL1RN, IL5, TNFA, and VEGF could be detected only in the conditioned media of stromal cells obtained from the ovarian endometriosis group. Among other cytokines detected in the conditioned media of both groups, CCL2 (P = 0.0018), CSF3 (P = 0.0017), IL1B (P = 0.0066), IL4 (P = 0.036), IL6 (P = 0.0039) and IL13 (P = 0.036) were found to be higher, whereas the concentration of IL18 was lower (P = 0.023) in the ovarian endometriosis group. Concentrations of CCL2, IL1B, IL4 and IL13 in conditioned medium reflected significant diagnostic performance for predicting ovarian endometriosis. Cellular phenotypic validation in vitro revealed an enhanced proliferative phenotype (P = 0.046) with no change in cell migratory capacity of endometrial stromal cells from the ovarian endometriosis group.

CONCLUSIONS

Endometrial stromal cells derived from severe ovarian endometriosis samples displayed a hyperinflammatory and hyperproliferative bias in the endometrial stroma during the 'window of implantation' putatively causing loss of fecundability.

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.

Intrauterine perfusion immunotherapies in recurrent implantation failures: Systematic review

Studies have investigated the gestational outcomes of new immunological therapies in the treatment of patients with recurrent implantation failure (RIF) in assisted reproductive technology (ART). The objective of this article is to assess the current state of evidence available in the literature on intrauterine perfusion immunotherapies in women undergoing ART treatments. By considering the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), the authors performed systematic review by searching the databases of PubMed/MEDLINE and Scopus using the following key words: "recurrent implantation failure," "intrauterine infusion," "Platelet-Rich Plasma (PRP)," "Peripheral Blood Mononuclear Cells (PBMC)," "Granulocyte Colony-Stimulating Factor (G-CSF)," and "Human Chorionic Gonadotropin (hCG)." The authors analyzed the indications and the impact of new immunological therapies with intrauterine infusions on the pregnancy outcomes of patients undergoing ART. PRP, PBMC, G-CSF, and hCG were the four most used immunological therapies with intrauterine infusion. These new therapies appear to improve the results of ART treatments in cases of RIF. However, the small number of studies does not allow definitive conclusions about the effectiveness of these therapies.

Transcriptomic changes and potential regulatory mechanism of intrauterine human chorionic gonadotropin co-cultured with peripheral blood mononuclear cells infusion in mice with embryonic implantation dysfunction

Background

This study aimed to explore whether intrauterine infusion of peripheral blood mononuclear cells (PBMCs) could induce favorable transcriptomic changes in the endometrium for embryo implantation and the potential mechanism.

Methods

Twenty-one mice were randomly divided to five groups, including a normal pregnancy (NP) group, an embryo implantation dysfunction (EID) group, an EID with human chorionic gonadotropin (hCG) group, an EID with PBMCs group, and an EID with hCG co-cultured with PBMCs group. The endometrium in the implantation window from mice were collected and determined by RNA sequencing (RNA-Seq), and the expression of significantly different genes with high degree of coincidence was recommended and validated by quantitative real-time polymerase chain reaction (qRT-PCR).

Results

There were totally 1,366 up-regulated and 1,374 down-regulated genes in the EID mice compared with the normal pregnant mice. We selected (fold change ≥2, P<0.05) and verified the candidate genes associated with embryo implantation, immune response and other reproductive processes in previous reports by qRT-PCR. Leukemia inhibitory factor (LIF), solute carrier family 15 member 2 (SLC15A2), retinoic acid receptor responder 1 (RARRES1), vascular cell adhesion molecule 1 (VCAM1) were down-regulated and musculin (MSC), chemokine (C-X-C motif) ligand 14 (CXCL14) were up-regulated significantly in EID group (P<0.05), and the synergistic effects of hCG were seen. In addition, the expression of glucocorticoid receptor (GR)-β in PBMCs of NP mice was higher than that of EID mice, and up-regulated GR-β in EID mice could significantly increase the expression of LIF, SLC15A2, RARRES1 and VCAM1, and decrease the expression of CXCL14 and MSC, which indicated GR-β might be a transcriptional factor of the six genes above.

Conclusions

Intrauterine PBMCs perfusion might improve the performance of impaired endometrial receptivity by regulating LIF, SLC15A2, RARRES1, VCAM1, MSC as well as CXCL14, and hCG could enhance the effect of PBMCs. In addition, GR-β, as a transcriptional factor, could regulate the six genes in PBMCs.

Promoting Roles of Embryonic Signals in Embryo Implantation and Placentation in Cooperation with Endocrine and Immune Systems

Embryo implantation in the uterus is an essential process for successful pregnancy in mammals. In general, the endocrine system induces sufficient embryo receptivity in the endometrium, where adhesion-promoting molecules increase and adhesion-inhibitory molecules decrease. Although the precise mechanisms remain unknown, it is widely accepted that maternal–embryo communications, including embryonic signals, improve the receptive ability of the sex steroid hormone-primed endometrium. The embryo may utilize repulsive forces produced by an Eph–ephrin system for its timely attachment to and subsequent invasion through the endometrial epithelial layer. Importantly, the embryonic signals are considered to act on maternal immune cells to induce immune tolerance. They also elicit local inflammation that promotes endometrial differentiation and maternal tissue remodeling during embryo implantation and placentation. Additional clarification of the immune control mechanisms by embryonic signals, such as human chorionic gonadotropin, pre-implantation factor, zona pellucida degradation products, and laeverin, will aid in the further development of immunotherapy to minimize implantation failure in the future.

Steroids, Pregnancy and Fetal Development

Maternal glucocorticoids critically rise during pregnancy reaching up to a 20-fold increase of mid-pregnancy concentrations. Concurrently, another steroid hormone, progesterone, increases. Progesterone, which shows structural similarities to glucocorticoids, can bind the intracellular glucocorticoid receptor, although with lower affinity. Progesterone is essential for the establishment and continuation of pregnancy and it is generally acknowledged to promote maternal immune tolerance to fetal alloantigens through a wealth of immunomodulatory mechanisms. Despite the potent immunomodulatory capacity of glucocorticoids, little is known about their role during pregnancy. Here we aim to compare general aspects of glucocorticoids and progesterone during pregnancy, including shared common steroidogenic pathways, plasma transporters, regulatory pathways, expression of receptors, and mechanisms of action in immune cells. It was recently acknowledged that progesterone receptors are not ubiquitously expressed on immune cells and that pivotal features of progesterone induced- maternal immune adaptations to pregnancy are mediated via the glucocorticoid receptor, including e.g., T regulatory cells expansion. We hypothesize that a tight equilibrium between progesterone and glucocorticoids is critically required and recapitulate evidence supporting that their disequilibrium underlie pregnancy complications. Such a disequilibrium can occur, e.g., after maternal stress perception, which triggers the release of glucocorticoids and impair progesterone secretion, resulting in intrauterine inflammation. These endocrine misbalance might be interconnected, as increase in glucocorticoid synthesis, e.g., upon stress, may occur in detriment of progesterone steroidogenesis, by depleting the common precursor pregnenolone. Abundant literature supports that progesterone deficiency underlies pregnancy complications in which immune tolerance is challenged. In these settings, it is largely yet undefined if and how glucocorticoids are affected. However, although progesterone immunomodulation during pregnancy appear to be chiefly mediated glucocorticoid receptors, excess glucocorticoids cannot compensate by progesterone deficiency, indicating that additional und still undercover mechanisms are at play.

Placenta specific protein-1 in recurrent pregnancy loss and in In Vitro Fertilisation failure: a prospective observational case-control study

Observations from studies have provided evidence that Placenta-specific protein1 (PLAC1) is important for the establishment and maintenance of pregnancy and suggest it as a potential biomarker for gestational pathologies. The aim of this study is to investigate whether maternal serum PLAC1 levels have any impact on etiopathogenesis of recurrent pregnancy loss (RPL) and repeated implantation failure after In Vitro Fertilisation (RIF). We conducted a prospective observational case-control study in a Research Hospital. Twenty-eight patients with RPL (group 1), 30 patients with unexplained infertility and RIF (group 2), 29 fertile patients (group 3) were included. The demographic features and serum PLAC1 levels were compared. There was a significant difference in PLAC1 levels between the groups (group 1 = 19.71 + 16.55 ng/ml; group 2 = 4.82 + 1.44 ng/ml; group 3 = 0.89 + 0.62 ng/ml, respectively) (p=.001). Positive correlation was found between serum PLAC1 levels and abortion rates (r = 0.64; p=.001), a negative correlation was found between serum PLAC1 levels and live birth rates (r = -0.69; p=.001). PLAC1 might have a negative effect on implantation in RPL and RIF. There may be a subgroup of PLAC with different bioactivity. There are no relevant studies conducted among these populations, further large-scale studies are needed to assess the molecular role of PLAC1 on implantation.IMPACT STATEMENTWhat is already known about this subject? PLAC1 (placenta-specific protein-1) gene is located on the X chromosome which encodes for a protein that is thought to be important for placental development although its role has not been clearly defined. Studies in the literature have provided evidence that PLAC1 has an important role in the establishment and maintenance of pregnancy and suggest it as a potential biomarker for gestational pathologies. Several reports over the past few years have demonstrated PLAC1 expression in a variety of human tumours including lung cancers, breast cancer, hepatocellular and colorectal cancers, gastric cancers and uterine cancers.What do the results of this study add? There have been no previous studies conducted among patients with recurrent pregnancy loss (RPL) or repeated implantation failure after In Vitro Fertilisation (RIF) that have searched for any association between PLAC1 levels and implantation failure. This study has demonstrated higher PLAC1 levels in infertile women with RIF and RPL for the first time; suggesting that it could have a negative effect on implantation in these populations. PLAC1 could be detected in the serum as a biomarker that is associated with RIF and RPL. What are the implications of these findings for clinical practice and/or further research? Defining the precise role of PLAC1 during implantation will provide new insight into understanding of poor reproductive outcomes such as RIF and RPL and help in developing treatment strategies. Further large-scale studies with more patients are needed to uncover the clinical value of PLAC1 as a biomarker to predict repeated implantation failure and RPL.

HHV-6A infection of endometrial epithelial cells affects immune profile and trophoblast invasion

PROBLEM

We first reported human herpesvirus (HHV)-6A DNA presence in 43% of endometrial cells from women with idiopathic infertility, whereas no fertile control women harbored the virus. We investigated the effect of HHV-6A infection on the immunological status of the endometrium.

METHOD OF STUDY

Endometrial biopsies, uterine flushing, and whole blood samples were collected from 67 idiopathic infertile women (mid-secretory phase). We analyzed the endometrial immunological status evaluating: (a) the effect of HHV-6A infection on endometrial immune profile analyzing the ratio of interleukin (IL)-15/ fibroblast growth factor-inducible 14 (Fn-14) and IL-18/ TNF-related weak inducer of apoptosis (TWEAK) mRNA as a biomarker of endometrial (e)natural killer activation/maturation, angiogenesis, and Th1/Th2 balance; (b) endometrial receptivity to trophoblasts in endometrial 3D in vitro model; (c) natural killer (NK) cells and T cells percentage and subpopulations by flow cytometry.

RESULTS

We confirmed the presence of HHV-6A infection in a 40% of idiopathic infertile women, characterized by an immune profile reflecting eNK cell cytotoxic activation and a decrease in CD4+ CD25+ CD127dim/^- regulatory T cells. The co-culture of endometrial epithelial cells with spheroids generated from the extravillous trophoblast-derived cell line JEG3 showed a twofold expansion of spheroids on endometrial epithelial-stromal cells (ESC) culture surface from HHV-6A negative women while no expansion was observed on the surface of ESC from HHV-6A positive women.

CONCLUSION

The identification of an effect of HHV-6A infection on endometrial immune status opens new perspectives in idiopathic infertile women care management. In addition, it would be possible to select antiviral therapies as novel, non-hormonal therapeutic approaches to those idiopathic infertile women characterized by the presence of endometrial HHV-6A infection, to increase their pregnancy rate.

The effects of human umbilical cord-derived mesenchymal stem cell transplantation on endometrial receptivity are associated with Th1/Th2 balance change and uNK cell expression of uterine in autoimmune premature ovarian failure mice

Background

To explore the mechanism of human umbilical cord-derived mesenchymal stem cell (hUMSC) transplantation to improve ovarian function and the endometrial receptivity in autoimmune premature ovarian failure (POF) mice.

Methods

The POF model was established in mice treated with zona pellucida 3 polypeptide fragment (zona pellucida 3, ZP3). The hUMSCs were transplanted into the POF mice through tail vein injection. Following the transplantation, the serum hormone levels of follicle stimulating hormone (FSH), estrogen (E₂), progesterone (P), γ-interferon (IFN-γ), interleukin-2 (IL-2), and interleukin-4 (IL-4) were evaluated by ELISA analysis. Morphological changes of ovarian and uterus tissues were examined by HE staining and immunohistochemistry. The expression of Th1/Th2 cytokines of T cells in spleen and CD56⁺CD16⁻ cells (uterine natural killer cells, uNK cells) in uterine was measured by flow cytometry (FCM) and immunohistochemistry. The expression of HOXA10 in uterine endometrium was examined by immunohistochemistry and RT-PCR analysis. The pinopodes of epithelial cells in uterine endometrium were examined by scanning electron microscopy.

Results

Following hUMSC transplantation, the serum levels of E₂, P, and IL-4 were increased but FSH, IFN-γ, and IL-2 levels were decreased in POF mice. Also, the transplantation of hUMSCs caused an increase in total number of healthy follicles and decrease of atresia follicles. The expression of HOXA10 gene was significantly increased but the CD56⁺CD16⁻ uNK cells decreased in the endometrium of uterine. The ratio of Th1/Th2 cytokines was also significantly decreased.

Conclusion

The data suggest that the recovery of ovarian function and endometrial receptivity in POF mice was regulated by the balance of Th1/Th2 cytokines and expression of uNK cells in the endometrium following hUMSC transplantation.

Endometrium immunomodulation by intrauterine insemination administration of treated peripheral blood mononuclear cell prior frozen/thawed embryos in patients with repeated implantation failure

In assisted reproductive technology (ART) programmes, approximately 10% of infertile patients have at least two or three repeated implantation failures (RIFs) after an in vitro fertilization (IVF) protocol. Successful implantation mainly depends on local immune tolerance mechanisms involving a spectrum of cytokines, interleukins and growth factors. The latter have played pivotal roles in the recruitment of immune cells (and notably T-lymphocyte cells). In total, 250 couples participating in frozen-thawed embryo transfer programme were incorporated in a randomized clinical trial (peripheral blood mononuclear cells (PBMC) subgroup: n=122; control subgroup: n=128). In the PBMC group, a blood sample was collected 5 days before the scheduled frozen-thawed embryo transfer; PBMCs were isolated using Ficoll separation and then cultured for 72 h. Two days prior to embryo transfer, 0.4 ml of cultured PBMCs were transferred into the patient's uterus. Although the clinical pregnancy rate was higher in the PBMC group (34.4%) than in the control group (23.4%), this difference was not statistically significant (P=0.05 in a chi-squared test). Nevertheless, when we limited the analysis to patients with ≥3 RIFs (n=138), there was a significant difference in the clinical pregnancy rate between the PBMC group (38.6%) and the control group (19.7%; P=0.01). Our results imply that PBMC transfer can be part of effective fertility treatment for patients with RIF.