Endometriosis with infertility: A comprehensive review on the role of immune deregulation and immunomodulation therapy

The role of innate and adaptive immunity in endometriosis

The innate and adaptive immune systems are the two key branches that determine host protection at all mucosal surfaces in human body, including the female reproductive tract. The pattern recognition receptors within the host that recognize pathogen-associated molecular patterns are expressed on the cells of the innate immune system. Rapidly reactive, theinnate immune system, responds immediately to the presence of infectious or other non-self agents, thereby launching an inflammatory response to protect the host until the activation of slower adaptive immune system. Macrophages, dendritic cells, and toll-like receptors are integral components of the innate immune system. In contrast, T-helper (Th1/Th2/Th17) cells and regulatory T (Treg) cells are the primary components of adaptive immune system. Studies showed that the growth and progression of endometriosis continue even in unilateral ovariectomized animal suggesting that besides ovarian steroid hormones, the growth of endometriosis could be regulated by innate/adaptive immune systems in pelvic environment. Recent reports demonstrated a potential role of Th1/Th2/Th17/Treg cells either individually or collectively in the initiation, maintenance, and progression of endometriosis. Herewe review the fundamental knowledge of innate and adaptive immunity and elaborate the role of innate and adaptive immunity in endometriosis based on both human and experimental data.

Correlation of Glycolysis-immune-related Genes in the Follicular Microenvironment of Endometriosis Patients with ART Outcomes

Endometriosis (EMT) -related infertility has been a challenge for clinical research. Many studies have confirmed that abnormal alterations in the immune microenvironment and glycolysis are instrumental in causing EMT-related infertility. Recently, our research team identified several key glycolysis-immune-related genes in the endometrial cells of EMT patients. This study aimed to further investigate the expression patterns of pyruvate dehydrogenase kinase 3 (PDK3), glypican-3 (GPC3), and alcohol dehydrogenase 6 (ADH6), which are related to glycolysis and immunity, in the follicular microenvironment of infertile patients with EMT using enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR) assays. According to the results, compared to the patients with tubal factor infertility, the concentrations of PDK3 and GPC3 were considerably increased in the follicular environment of EMT patients, while ADH6 expression was significantly reduced. The number of oocytes retrieved, the transferable embryo rate, and the cumulative clinical pregnancy rate of EMT patients were significantly reduced, and there was a correlation with the level of PDK3, GPC3, and ADH6 in Follicular Fluid (FF). The area under the receiver operating characteristic (ROC) curve for predicting clinical pregnancy in infertile patients with EMT for PDK3, GPC3, ADH6, and their combination was 0.732, 0.705, 0.855, and 0.879, respectively (P < 0.05). In conclusion, our research indicates that glycolysis-immune-related genes may contribute to infertility in EMT patients through immune infiltration, and disruption of mitochondrial and oocyte functions. The combined detection of PDK3, GPC3, and ADH6 in FF helps to predict clinical pregnancy outcomes in infertile patients with EMT.

Role of Molecular Biomarkers in Endometriosis-Related Infertility: A Narrative Review of the Literature

Endometriosis is a chronic benign inflammatory disease that affects women of reproductive age. The clinical presentations of endometriosis include dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility. There is a well-established association between endometriosis and infertility. Therefore, there is a need for an early diagnosis of endometriosis-related infertility. In this study, we aim to identify the role of biomarkers as predictive factors of the presence of the disease and its severity and their correlation with the pregnancy outcome. We performed an electronic database search of all published studies in PubMed and EMBASE from January 2018 to May 2023. Numerous innovative biomarkers identified in cases of endometriosis and infertility have been studied over the past years, including micro-RNAs, BCL6 endometrial expression, cytotoxic T-lymphocyte antigen 4, human leukocyte antigen G, programmed cell death protein 1, programmed cell death ligand 1 immune checkpoint molecules, plasma fibronectin-fibrin complexes, homeobox A10 gene, systemic inflammatory response markers, uterine natural killer cells, and the eutopic endometrium proteome. Considerable research has been done to identify diagnostic biomarkers for the early detection and prevention of endometriosis-associated infertility. However, none of these biomarkers displayed enough diagnostic accuracy to be used in daily clinical practice. Future research is valuable to establish them as reliable diagnostic tools.

Causal effects of endometriosis on SLE, RA and SS risk: evidence from meta-analysis and Mendelian randomization

BACKGROUND

Endometriosis is an underdiagnosed disorder that affects an estimated 6-10% of women of reproductive age. Endometriosis has been reported in epidemiological studies to be associated with autoimmune diseases. However, the relationship remains controversial.

METHODS

A meta-analysis of observational studies was undertaken to evaluate the risk of autoimmune diseases in patients with endometriosis. The relevant studies were retrieved via the databases Medline, Embase and Web of Science until July 20, 2023. Mendelian randomization (MR) was subsequently utilized to scrutinize the causal influence of genetic predisposition toward endometriosis on three autoimmune diseases.

RESULTS

The meta-analysis findings revealed a relationship between endometriosis and the onset of SLE (cohort studies: RR = 1.77, 95% confidence interval (CI): 1.47-2.13, I2 = 0%; Case-control and cross-sectional studies: OR = 5.23, 95% CI: 0.74-36.98, I2 = 98%), RA (cohort studies: RR = 2.18, 95% CI: 1.85-2.55, I2 = 92%; Case-control and cross-sectional studies: OR = 1.40, 95% CI: 1.19-1.64, I2 = 0%) and SS (cohort studies: RR = 1.49, 95% CI: 1.34-1.66, I2 = 0%). Similarly, in our MR study, the results of the inverse-variance-weighted (IVW) model suggested that genetic predisposition to endometriosis was causally associated with an increased risk for SLE (OR = 1.915, 95% CI: 1.204-3.045, p = 0.006) and RA (OR = 1.005, 95% CI: 1.001-1.009, p = 0.014).

CONCLUSIONS

Both our meta-analysis and MR study indicate that endometriosis increases the risk of autoimmune diseases. These findings not only broaden our understanding of the genetic mechanisms underlying the comorbidity of endometriosis and autoimmune diseases, but also offer a new strategy for autoimmune disease prevention.

The Association Between Daily Intake of Dietary Supplements and Self-Reported Endometriosis: A NHANES-Based Study

Dietary supplements are gaining recognition as potential influencers of female reproductive health, but their connection to endometriosis risk remains underexplored. This study addressed this gap, examining the impact of daily dietary supplement intake on the initiation and progression of endometriosis. To explore this, a cross-sectional study was conducted involving 3950 participants representative of the US population from the 1999-2006 National Health and Nutrition Examination Survey (NHANES). Infertility was determined by a question on year-long attempts to become pregnant. Unweighted and weighted multivariate logistic regression analyses assessed the association between dietary supplements and endometriosis risk. Subgroup analysis was conducted based on the participants' body mass index (BMI). The results revealed intriguing patterns. Specifically, higher dietary fiber content (Q4 vs Q1: OR = 0.56, 95% CI = (0.37,0.84), P = 0.0062) and density (Q4 vs Q1: OR = 0.55, 95% CI = (0.38,0.81), P = 0.0035) were linked to reduced risk of endometriosis. Protein content (Q4 vs Q1: OR = 0.47, 95% CI = (0.31,0.74), P = 0.0011) and density (Q4 vs Q1: OR = 0.63, 95% CI = (0.45,0.88), P = 0.0096) similarly exhibited a negative association with endometriosis risk. Interestingly, when stratified by BMI, these effects were pronounced in normal-weight women, whereas they were not evident in the overweight and obese subgroup. Protein content and density showed no significant associations across subpopulations. In conclusion, this study established a negative relationship between dietary fiber and endometriosis, particularly notable in normal-weight women. Future research is essential to validate these findings and establish a causal link between dietary fiber and endometriosis.

Progesterone Hypersensitivity in Assisted Reproductive Technologies: Implications for Safety and Efficacy

The global rise in the age of childbirth, influenced by changing sociodemographic patterns, has had a notable impact on fertility rates. Simultaneously, assisted reproductive techniques (ARTs) have become increasingly prevalent due to advancements in reproductive medicine. The paper explores the intersection between the surge in ARTs and the rising number of iatrogenic autoimmune progesterone dermatitis (APD). Autoimmune progesterone dermatitis, commonly known as progesterone hypersensitivity, manifests itself as a mucocutaneous hypersensitivity syndrome. It is characterized by a wide range of dermatological symptoms, with urticaria and maculopapular rashes being the most prominent signs. Concurrently, systemic symptoms, such as fever, angioedema, and, in severe instances, anaphylaxis, may ensue. This dermatologic condition poses a significant challenge to women of childbearing age. This intricate syndrome frequently manifests itself in conjunction with menstruation or pregnancy as a reaction to physiological fluctuations in endogenous progesterone. However, given that exposure to exogenous progesterone is an integral component of various modern therapies, secondary APD has also been described. Our findings unveil a heightened likelihood of developing secondary progesterone hypersensitivity in ART patients that is attributed to the administration of exogenous progesterone through intramuscular, intravaginal, and oral routes. The study also explores available therapeutic interventions for facilitating viable pregnancies in individuals grappling with autoimmune progesterone dermatitis within the context of ARTs. This comprehensive analysis contributes valuable insights into the intricate relationship between reproductive technologies, dermatological challenges, and successful pregnancy outcomes.

Pregnancy Outcomes in Patients with Primary Sjögren's Syndrome Undergoing Assisted Reproductive Therapy: A Multi-center Retrospective Study

INTRODUCTION

The aim of this work was to investigate the pregnancy outcomes in infertile patients with primary Sjögren's syndrome (pSS) undergoing assisted reproductive therapy (ART).

METHODS

A multi-center retrospective study was performed in pregnant women with pSS and ART from five tertiary hospitals from Guangdong Province from 2013 to 2022. Natural planned pregnancy in pSS and healthy people undergoing ART were selected as controls. Pregnancy outcomes were collected from medical records and compared among groups.

RESULTS

Twenty-four pregnancies in pSS with ART, 70 natural planned pregnancies in pSS, and 96 pregnancies in healthy people with ART were analyzed. More than half of the pSS mothers undergoing ART have a past history of adverse pregnancy and spontaneous abortion was the most common (10/24, 41.7%). Primary infertility (25.0%) and recurrent spontaneous abortion (16.7%) were the leading causes of infertility in pSS. The major maternal adverse pregnancy outcome (APO) in pSS patients with ART was premature delivery (11/24, 45.8%), likely attributed to twin gestation (4/11, 36.4%) and fetal distress (3/11, 27.3%). Twenty-seven live infants were born from 22 successful deliveries. The live birth rate was 93.1% (27/29). The average delivery time was 36.1 ± 3.3 weeks of gestation. The average birthweight was 2434.4 ± 722.1 g, compared with 2844.9 g in natural planned pregnancy in pSS, and 3072.1 g from healthy mothers with ART (P < 0.001). Seven (25.9%) low-birthweight (LBW) infants were born, and the incidence was comparable to the other two groups (22.2% in natural pregnancy, 13.0% in healthy people, P = 0.09). No infants developed congenital heart block (CHB).

CONCLUSIONS

ART is an effective method for infertility in patients with pSS. Premature delivery is the leading maternal APOs. The incidence of fetal APOs does not increase, while birthweight is lower in offspring from pSS mothers with ART.

Recent insights explaining susceptibility to endometriosis-From genetics to environment

Endometriosis is a disease with a heterogeneous pathogenesis, explained by multiple theories, and also with a polymorphic presentation. The purpose of this literature review is to systematize the genetic, inflammatory, and environmental factors related to the pathophysiology of endometriosis. Current evidence suggests that endometriosis is a complex inherited genetic condition, in which the genes that determine susceptibility to the disease interact with the environment to develop different phenotypes. Genetic variants associated with risk of endometriosis have been identified in several genome-wide association studies, in addition to a group of genes related to the pathophysiology of endometriosis, namely the estrogen, progesterone and androgen receptors and the cytochrome P450 gene, as well as the p53 gene. The role of inflammation is controversial; however, it is an essential process, both in the initiation and perpetuation of the disease, in and outside the pelvis. Alterations in reactive oxygen species pathways that consequently determine oxidative stress are typical in the inflammatory environment of endometriosis. The role of environmental factors is a relatively new and broad-spectrum topic, with inconsistent evidence. Multiple factors have been studied such as endocrine-disrupting chemicals, metals, intrauterine exposure to diethylstilbesterol and lifestyle risk factors. In conclusion, endometriosis remains a mysterious condition, with multifactorial factors involved in its pathophysiology. The progress that has been made in the genetic predisposition to endometriosis may allow the establishment of new therapeutic targets. On the other hand, understanding the role of the environment in this disease may allow preventive intervention, minimizing its incidence and/or severity. This article is categorized under: Reproductive System Diseases > Molecular and Cellular Physiology Reproductive System Diseases > Environmental Factors Reproductive System Diseases > Genetics/Genomics/Epigenetics.

Spatiotemporal Trends and Age-Period-Cohort Analysis for the Burden of Endometriosis-Related Infertility: An Analysis of the Global Burden of Disease Study 2019

BACKGROUND

Endometriosis is a common nonfatal gynecological disease, and infertility is one of its main dangers. Endometriosis-related infertility causes serious damage to women's health and places a burden on women of reproductive age. The aim of this study was to describe the current burden of endometriosis-associated infertility and to analyze its spatiotemporal trends.

METHODS

Age-standardized prevalence rate (ASPR) data from 1990 to 2019 for Endometriosis-related primary infertility (ERPI) and secondary infertility (ERSI) were obtained from the Global Burden of Disease Study (GBD) 2019. These data spanning three decades cover the global, sociodemographic index (SDI) regions, GBD regions, and 204 countries and territories. Spatiotemporal trends were analyzed by calculating the estimated annual percentage change (EAPC) and using a time-period-cohort model.

RESULTS

Globally, the ASPR of ERPI and ERSI showed a weak downward trend from 1990 to 2019, with EAPCs of -1.25 (95% CI: -1.39 to -1.11) and -0.6 (95% CI: -0.67 to -0.53), respectively. The spatiotemporal trends in ERPI and ERSI varied substantially between regions and age groups. When endometriosis-related infertility burden was linked to SDI values, a strong negative correlation was observed between the ASPR of ERSI and its EAPC and SDI values. When modeling with age-period-cohort, ERPI burden was found to be highest at ages 20-25 years, while ERSI burden was persistently higher at ages 20-45 years. Using 2000-2004 as the reference period, both ERPI and ERSI burden decreased with each year among women. Significant variability in burden between regions was found for the birth cohort factor.

CONCLUSIONS

The global burden of endometriosis-related infertility declined minimally from 1990 to 2019. However, this burden varied considerably across regions, age groups, periods, and birth cohorts. The results of this study reflect spatiotemporal trends in the burden of endometriosis-related infertility over the study period and may be used to help improve health management, develop timely and effective prevention and control strategies, and provide epidemiologic theoretical evidence for reducing the burden for endometriosis-related infertility.

FDX1 enhances endometriosis cell cuproptosis via G6PD-mediated redox homeostasis

Cuproptosis is a new form of programmed cell death, which is associated with the mitochondrial TCA (tricarboxylic acid) cycle. But the functions of cuproptosis in endometriosis progression are still unknown. Here, we find that cuproptosis suppresses the growth of endometriosis cells and the growth of ectopic endometrial tissues in a mouse model. FDX1 as a key regulator in cuproptosis pathway could promote cuproptosis in endometriosis cells. Interestingly, FDX1 interacts with G6PD, and reduces its protein stability, which predominantly affects the cellular redox-regulating systems. Then, the reduced G6PD activity enhances cuproptosis via down-regulating NADPH and GSH levels. Collectively, our study demonstrates that FDX1 mediates cuproptosis in endometriosis via G6PD pathway, resulting in repression of endometriosis cell proliferation and metastasis.

Concomitant Autoimmunity in Endometriosis Impairs Endometrium-Embryo Crosstalk at the Implantation Site: A Multicenter Case-Control Study

Endometriosis and autoimmune diseases share a hyper-inflammatory state that might negatively impact the embryo-endometrium crosstalk. Inflammatory and immune deregulatory mechanisms have been shown to impair both endometrial receptivity and embryo competence at the implantation site. The aim of this study was to investigate the potential additional impact of co-existing autoimmunity in women affected by endometriosis on the early stages of reproduction. This was a retrospective, multicenter case-control study enrolling N = 600 women with endometriosis who underwent in vitro fertilization-embryo transfer cycles between 2007 and 2021. Cases were women with endometriosis and concomitant autoimmunity matched based on age and body mass index to controls with endometriosis only in a 1:3 ratio. The primary outcome was the cumulative clinical pregnancy rate (cCPR). The study found significantly lower cleavage (p = 0.042) and implantation (p = 0.029) rates among cases. Autoimmunity (p = 0.018), age (p = 0.007), and expected poor response (p = 0.014) were significant negative predictors of cCPR, with an adjusted odds ratio of 0.54 (95% CI, 0.33-0.90) for autoimmunity. These results suggest that the presence of concomitant autoimmunity in endometriosis has a significant additive negative impact on embryo implantation. This effect might be due to several immunological and inflammatory mechanisms that interfere with both endometrial receptivity and embryo development and deserves further consideration.

Network Pharmacology Was Used to Predict the Active Components and Prospective Targets of Paeoniae Radix Alba for Treatment in Endometriosis

Endometriosis is one of the most common benign gynecologic diseases. Paeoniae Radix Alba (PRA) has been utilized to treat endometriosis. We wished to identify potential targets for PRA in the treatment of endometriosis, as well as to provide a groundwork for future studies into its pharmacological mechanism of action. Network pharmacology was employed to conduct investigations on PRA. Target proteins were chosen from the components of PRA for endometriosis treatment. A protein-protein interaction (PPI) was established using overlapping genes. Analyses of enrichment of function and signaling pathways were undertaken using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes databases to select "hub genes." Finally, the feasibility of analysis based on network pharmacology was determined using real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting. We demonstrated that PRA has 25 bioactive components and 167 putative targets that are therapeutically important. The anti-inflammatory and immune-boosting actions of tumor necrosis factor, albumin, signal transducer and activator of transcription (STAT)3, mitogen-activated protein kinase, Jun, interleukin (IL)-1B, prostaglandin-endoperoxide synthase 2, matrix metalloproteinase-9, vascular endothelial growth factor A, and IL-6 were identified as prospective targets. Seven major compounds in PRA and related to the STAT3 pathway could bind spontaneously to it. RT-qPCR and western blotting showed that expression of STAT3 and phospho-STAT3 was reduced significantly after PRA intervention. Hence, analyses of the active components of traditional Chinese medicine formulations through network pharmacology may open up new ideas for the treatment of diseases.

The effects of Rituximab on experimental endometriosis model in rats

AIM

Endometriosis is a common, chronic benign gynecologic disease and distresses women in their reproductive age. Yet the pathogenesis of endometriosis is not clear, multifactorial mechanisms have been characterized for the initiation, progression, and regression of this disease. It has been suggested that immune cells in the lymphoid lineage play essential roles in accepting or rejecting the survival, implantation, and proliferation of endometrial and endometriotic cells and, dysfunction of B-lymphocytes (B-cells) are one of the major causes for the progression of endometriosis. In this study, we aimed to evaluate the potential therapeutic efficacy of Rituximab, an inhibitor for B-cells, for endometriosis in an experimental animal model.

METHODS

Experimental endometriosis animal model has been utilized using mature female rats. Rats underwent surgery to initiate endometriosis on the abdominal wall. After confirming for endometriosis, rats were treated with either Rituximab or saline solution. After 14 days of treatment, implants were dissected, and evaluated for volumes and histological features. Anti-CD-20 antibody was used for immunohistochemistry scoring purposes.

RESULTS

There is significant decrease in the volume of endometriotic implants after treatment with Rituximab (188.81 ± 149.42 vs 20.37 ± 13.08, p = 0.001). There are also significant differences for the B-cell count and fibrosis score between the control and treatment groups (3.08 ± 2.6 vs 1.56 ± 1.42., p = 0.043).

CONCLUSION

In an experimental rat endometriosis model, we assessed Rituximab, an antibody for B-lymphocyte, as a candidate medical treatment for endometriosis. Additional studies are required to further evaluate the effects of Rituximab on the prevention of endometriosis.

Impact of endometriosis on embryo quality and endometrial receptivity in women undergoing assisted reproductive technology

ART is an important treatment method for infertile patients with endometriosis. However, the effects of endometriosis on embryo quality and endometrial receptivity remain unclear. Thus, we aimed to simultaneously investigate the impact of endometriosis and its stage on embryo quality and endometrial receptivity in women undergoing ART. We retrospectively analyzed the data from patients with and without endometriosis who underwent oocyte retrieval and/or high-quality embryos transfer between July 2015 and December 2020, including 1312 IVF cycles and 608 IVF or frozen-thawed embryo transfer (FET) cycles, respectively. The endometriosis group had a lower percentage of good cleavage-stage embryos and fertilization rates than those in the control group (p = 0.038 and 0.008, respectively). The number of retrieved oocytes, MII oocytes, cleavage, blastocysts, and blastulation rates was comparable between two groups. We found no significant difference in clinical pregnancy, implantation, live birth, miscarriage, or multiple pregnancy rates between the two groups among patients who transferred high-quality embryos. Stratification analysis showed that patients with stage III-IV endometriosis had fewer retrieved oocytes than those with stage I-II endometriosis (p = 0.012) and marginally fewer retrieved oocytes than the control group (p = 0.051). The stage I-II group had the lowest percentage of good cleavage-stage embryos, which was significantly lower than that of the control group (p = 0.043). In FET cycles, patients with stage III-IV endometriosis had a higher miscarriage rate than those in the control group (p = 0.023). Our results suggest that endometriosis does not alter endometrial receptivity but affects embryo quality, oocyte fertilization ability, and ovarian response.

Autoantibody screening of plasma and peritoneal fluid of patients with endometriosis

STUDY QUESTION

Are there specific autoantibody profiles in patients with endometriosis that are different from those in controls?

SUMMARY ANSWER

This study did not reveal a significantly higher prevalence of autoantibodies in the studied groups of patients.

WHAT IS KNOWN ALREADY

Various inflammatory factors are postulated to be involved in the pathomechanisms of endometriosis, and a potential link exists with autoimmune diseases, which may also play an important role. As the diagnosis of endometriosis remains invasive, it can only be confirmed using laparoscopy with histopathological examination of tissues. Numerous studies have focused on identifying useful biomarkers to confirm the disease, but without unequivocal effects. Autoantibodies are promising molecules that serve as potential prognostic factors.

STUDY DESIGN, SIZE, DURATION

A multicentre, cross-sectional study was conducted over 18 months (between 2018 and 2019), at eight Departments of Obstetrics and Gynaecology in several cities across Poland on 137 patients undergoing laparoscopic examination for the diagnosis of endometriosis.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

During laparoscopy, we obtained plasma samples from 137 patients and peritoneal fluid (PF) samples from 98 patients. Patients with autoimmune diseases were excluded from the study. Autoantibody profiling was performed using HuProt v3.1 human proteome microarrays.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed no significant differences in the expression of autoantibodies in the plasma or PF between the endometriosis and control groups. The study revealed that in the PF of women with Stage II endometriosis, compared with other stages, there were significantly higher reactivity signals for ANAPC15 and GABPB1 (adj. P < 0.016 and adj. P < 0.026, respectively; logFC > 1 in both cases). Comparison of the luteal and follicular phases in endometriosis patients revealed that levels of NEIL1 (adj. P < 0.029), MAGEB4 (adj. P < 0.029), and TNIP2 (adj. P < 0.042) autoantibody signals were significantly higher in the luteal phase than in the follicular phase in PF samples of patients with endometriosis. No differences were observed between the two phases of the cycle in plasma or between women with endometriosis and controls. Clustering of PF and plasma samples did not reveal unique autoantibody profiles for endometriosis; however, comparison of PF and plasma in the same patient showed a high degree of concordance.

LIMITATIONS, REASONS FOR CAUTION

Although this study was performed using the highest-throughput protein array available, it does not cover the entire human proteome and cannot be used to study potentially promising post-translational modifications. Autoantibody levels depend on numerous factors, such as infections; therefore the autoantibody tests should be repeated for more objective results.

WIDER IMPLICATIONS OF THE FINDINGS

Although endometriosis has been linked to different autoimmune diseases, it is unlikely that autoimmune responses mediated by specific autoantibodies play a pivotal role in the pathogenesis of this inflammatory disease. Our study shows that in searching for biomarkers of endometriosis, it may be more efficient to use higher-throughput proteomic microarrays, which may allow the detection of potentially new biomarkers. Only research on such a scale, and possibly with different technologies, can help discover biomarkers that will change the method of endometriosis diagnosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by a grant from the Polish Ministry of Health (grant no. 6/6/4/1/NPZ/2017/1210/1352). It was also funded by the Estonian Research Council (grant PRG1076) and the Horizon 2020 Innovation Grant (ERIN; grant no. EU952516), Enterprise Estonia (grant no. EU48695), and MSCA-RISE-2020 project TRENDO (grant no. 101008193). The authors declare that there is no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Risk factors associated with preterm birth in singletons born after IVF: a national cohort study

RESEARCH QUESTION

What are the risk factors for prematurity other than intrauterine growth restriction in singletons after IVF?

DESIGN

Data were collected from a national registry, based on an observational prospective cohort of 30,737 live births after assisted reproductive technology (fresh embryo transfers: n = 20,932 and frozen embryo transfer [FET] n = 9805) between 2014 and 2015. A population of not-small for gestational age singletons conceived after fresh embryo transfers and FET, and their parents, was selected. Data on a number of variables were collected, including type of infertility, number of oocytes retrieved and vanishing twins.

RESULTS

Preterm birth occurred in 7.7% (n = 1607) of fresh embryo transfers and 6.2% (n = 611) of frozen-thawed embryo transfers (P < 0.0001; adjusted odds ratio [aOR] = 1.34 [1.21-1.49]). Endometriosis and vanishing twin increased the risk of preterm birth after fresh embryo transfer (P < 0.001; aOR 1.32 and 1.78, respectively). Polycystic ovaries or more than 20 oocytes retrieved also increased preterm birth risk (aOR 1.31 and 1.30; P = 0.003 and P = 0.02, respectively); large oocyte cohort (>20) was no longer associated with the risk of prematurity in FET.

CONCLUSION

Endometriosis remains a risk for prematurity even in the absence of intrauterine growth retardation, which suggests a dysimmune effect. Large oocyte cohorts obtained by stimulation, without clinical polycystic ovary syndrome diagnosed before attempts, do not affect FET outcomes, reinforcing the idea of a phenotypic difference in the clinical presentation of polycystic ovary syndrome.

U0126 and BAY11-7082 Inhibit the Progression of Endometriosis in a Rat Model by Suppressing the MEK/ERK/NF-κB Pathway

Endometriosis is an aggressive disease. It is the main cause of chronic pelvic pain, dysmenorrhea, and infertility, affecting the well-being of women. This study aimed to explore the role of U0126 and BAY11-7082 in endometriosis (EMs) treatment in rats by targeting the MEK/ERK/NF-κB pathway. The EMs model was generated and the rats were divided into model, dimethyl sulfoxide, U0126, BAY11-708, and control groups (Sham operation group). After 4 weeks of treatment, the rats were sacrificed. Compared with model group, U0126 and BAY11-7082 treatment significantly inhibited ectopic lesion growth, glandular hyperplasia, and interstitial inflammation. Compared to control group, PCNA and MMP9 levels were significantly increased in the eutopic and ectopic endometrial tissues of model group; the levels of MEK/ERK/NF-κB pathway proteins also increased significantly. Compared with model group, MEK, ERK, and NF-κB levels decreased significantly after U0126 treatment and NF-κB protein expression decreased significantly after BAY11-7082 treatment, with no significant difference in MEK and ERK levels. The proliferation and invasion activities of eutopic and ectopic endometrial cells also significantly decreased after U0126 and BAY11-7082 treatment. In summary, our results showed that U0126 and BAY11-7082 inhibited ectopic lesion growth, glandular hyperplasia, and interstitial inflammatory response in EMs rats by inhibiting the MEK/ERK/NF-κB signaling pathway.

Pattern-recognition receptors in endometriosis: A narrative review

Endometriosis is closely associated with ectopic focal inflammation and immunosuppressive microenvironment. Multiple types of pattern recognition receptors (PRRs) are present in the innate immune system, which are able to detect pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) in both intracellular and external environments. However, the exact role of PRRs in endometriosis and the underlying molecular mechanism are unclear. PRRs are necessary for the innate immune system to identify and destroy invasive foreign infectious agents. Mammals mainly have two types of microbial recognition systems. The first one consists of the membrane-bound receptors, such as toll-like receptors (TLRs), which recognize extracellular microorganisms and activate intracellular signals to stimulate immune responses. The second one consists of the intracellular PRRs, including nod-like receptors (NLRs) and antiviral proteins retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA-5) with helix enzyme domain. In this review, we mainly focus on the key role of PRRs in the pathological processes associated with endometriosis. PRRs recognize PAMPs and can distinguish pathogenic microorganisms from self, triggering receptor ligand reaction followed by the stimulation of host immune response. Activated immune response promotes the transmission of microbial infection signals to the cells. As endometriosis is characterized by dysregulated inflammation and immune response, PRRs may potentially be involved in the activation of endometriosis-associated inflammation and immune disorders. Toll-like receptor 2 (TLR2), toll-like receptor 3 (TLR3), toll-like receptor 4 (TLR4), nod-like receptor family caspase activation and recruitment domain (CARD) domain containing 5 (NLRC5), nod-like receptor family pyrin domain containing 3 (NLRP3), and c-type lectin receptors (CLRs) play essential roles in endometriosis development by regulating immune and inflammatory responses. Absent in melanoma 2 (AIM2)-like receptors (ALRs) and retinoic acid-inducible gene I-like receptors (RLRs) may be involved in the activation of endometriosis-associated immune and inflammation disorders. PRRs, especially TLRs, may serve as potential therapeutic targets for alleviating pain in endometriosis patients. PRRs and their ligands interact with the innate immune system to enhance inflammation in the stromal cells during endometriosis. Thus, targeting PRRs and their new synthetic ligands may provide new therapeutic options for treating endometriosis.

Increased expression of NLRP3 inflammasome components in granulosa cells and follicular fluid interleukin(IL)-1beta and IL-18 levels in fresh IVF/ICSI cycles in women with endometriosis

The inflammasomes are a family of recently described multi-protein cytoplasmic sensors that orchestrate the inflammatory response and participate in a variety of inflammatory conditions. We hypothesized that the activation of pyrin domain‑containing protein 3 (NLRP3) inflammasome by granulosa cells (hGCs) may be activated in women with endometriosis and influence oocyte maturation and IVF outcomes. We performed a cross-sectional study to investigate the NLRP3 inflammasome status in follicular fluid (FF) and in hGCs from 44 women undergoing controlled ovarian stimulation for IVF/ICSI. Study subjects were divided into two groups according to the infertility etiology: group with tubal or male factor (control, n = 22) vs. group with endometriosis (n = 22). The FF IL-1beta and IL-18 levels in the endometriosis group were significantly higher than those in the non-endometriosis group, i.e., 5010 pg/mL and 2738 pg/mL, respectively (p < 0.05). No correlation was found between clinical pregnancy and live birth rate and analyzed inflammasome component levels (p > 0.05). In addition, the hGCs from endometriosis women demonstrated high expression of NLRP3 inflammasome at both protein and mRNA levels. Higher expression of inflammasome components within the ovary compartment may result from the exaggerated inflammatory state associated with endometriosis and thus impact the fertility of these women.

Higher miscarriage rate in subfertile women with endometriosis receiving unbiopsied frozen-warmed single blastocyst transfers

Background: Assisted reproductive technology treatment is recommended to overcome endometriosis-associated infertility but current evidence is controversial. Endometriosis is associated with lower antral follicle count (AFC) and oocyte yield but similar clinical outcomes compared to controls. Unaffected ovarian stimulation response and embryological outcomes but lower clinical pregnancy and live birth rates and higher miscarriage rates have been reported, implying direct impact on endometrial receptivity. With evidence emerging on the benefit of frozen-warmed and blastocyst stage transfer, we investigated ART outcomes in endometriosis using homogeneous case-control groups. Methods: This is a retrospective observational case-control study including n = 66 frozen-warmed unbiopsied single blastocyst transfers of patients with endometriosis and n = 96 of women exhibiting idiopathic sterility. All frozen-warmed transfers followed artificial endometrial preparation. Results: In control women, the mean number of oocytes recovered at oocyte pick up was higher compared to women with endometriosis (15.3 ± 7.1 vs. 12.7 ± 5.2, p = 0.025) but oocyte maturation index (mature oocytes/total oocytes at oocyte pick up) was significantly higher for endometriosis (48.2% vs. 34.0%, p = 0.005). The same was shown for the subgroup of 44 endometriosis patients after endometrioma surgery when compared with controls (49.1% vs. 34.0%, p = 0.014). Clinical pregnancy rate was not higher in endometriosis but was close to significance (47.0% vs. 32.3%, p = 0.059) while live birth rate was comparable (27.3% vs. 32.3%, p = 0.746). Miscarriage rate was higher in the endometriosis group (19.7% vs. 7.3%, p = 0.018). A significantly higher AFC was observed in the control group in comparison with the endometriosis group (16.3 ± 7.6 vs. 13.4 ± 7.0, p = 0.014). Live birth rate did not differ when comparing all endometriosis cases (p = 0.746), ASRM Stage I/II and Stage III/IV (p = 0.348 and p = 0.888) with the control group but the overall pregnancy rate was higher in ASRM Stage I/II (p = 0.034) and miscarriage rate was higher in ASRM Stage III/IV (p = 0.030) versus control. Conclusion: Blastocyst transfers in women with endometriosis originate from cycles with lower AFC but higher share of mature oocytes than in control women, suggesting that endometriosis might impair ovarian reserve but not stimulation response. A higher miscarriage rate, independent of blastocyst quality may be attributed to an impact of endometriosis on the endometrium beyond the timing of implantation.

The latest advances in the pharmacological management of endometriosis

INTRODUCTION

Endometriosis is a benign disease, characterized by a wide range of symptoms and different degrees of severity, which is why therapy should be individually adapted to the patient's needs. Over the years, a lot of research has gone into finding new therapeutic approaches for this enigmatic disease.

AREAS COVERED

This review presents the latest advances in pharmacological management of endometriosis and is solely focused on studies published from 2010 to 2021.

EXPERT OPINION

Clinicians and researchers are constantly searching for new therapeutic strategies for endometriosis patients. As there are well-established treatments, however, any new medication should fulfill at least one of the three criteria: increased efficacy, comparable efficacy but a better safety profile, or treatments that have a lack of accompanying contraceptive effects that are seen in most endometriosis treatments. While some new substances show promising results, further studies are needed to demonstrate the fulfillment of one of the above-mentioned criteria.

Role of inflammatory factors in the etiology and treatment of recurrent implantation failure

Recurrent implantation failure (RIF) is characterized by the absence of implantation after high-grade embryos are transferred to the endometrium by at least three in vitro fertilization cycles. It is one of the most important factors contributing to reproductive failure. After numerous barriers have been overcome to obtain good-quality embryos, RIF causes extreme distress and frustration in women and couples. In recent years, significant progress has been made in understanding how inflammatory factors, which include pro-inflammatory factors, anti-inflammatory factors, chemokines, and other molecules, contribute to RIF. Immunological abnormalities, hypercoagulability, and reproductive diseases are considered potential causes of RIF. In alloimmune disorders, inflammatory factors can affect the success rate of embryo implantation by altering T helper (Th)1/Th2 and Th17/regulatory T cell ratios and causing imbalances of uterine natural killer cells and macrophages. Autoimmune disorders can also lead to RIF. Inflammatory factors also play key roles in RIF-related disorders such as hypercoagulability, chronic endometritis, adenomyosis, hydrosalpinx, and endometriosis. This review focuses on the roles of inflammatory factors in RIF, including immune factors, blood hypercoagulable states, and reproductive diseases such as chronic endometritis, adenomyosis, hydrosalpinx, and endometriosis. It also summarizes the different treatments according to the causes of RIF and discusses the efficacy of sirolimus, peripheral blood mononuclear cells, low-dose aspirin combined with low-molecular-weight heparin, blocking interleukin-22, and gonadotropin-releasing hormone agonists in the treatment of RIF.

Implantation Failure in Endometriosis Patients: Etiopathogenesis

Embryo implantation requires adequate dialogue between a good quality embryo and a receptive endometrium. This implantation is still considered as the black box of reproductive medicine. Endometriosis is a highly prevalent chronic inflammatory disease, concerning about 10% of women of reproductive age and is one of the major causes of female infertility. The mechanisms involved in endometriosis-related infertility, an event not yet completely understood, are multifactorial and include anatomical changes, reduction in ovarian reserve, endocrine abnormalities, genetic profile, immunity markers, inflammatory mediators, or altered endometrial receptivity. In this article, we will focus on the impact of endometriosis on embryo quality and on endometrial receptivity. Results: Poor oocyte and embryo quality seem to promote a lower pregnancy rate, more than the endometrium itself in women with endometriosis. Other studies report the contrary. In addition, hormonal imbalance observed in the endometrium could also alter the embryo implantation. Conclusions: Controversial results in the literature add difficulties to the understanding of the mechanisms that lead to embryo implantation disorders. Furthermore, either oocyte/embryo impairment, altered endometrium, or both may cause impaired implantation. New prospective, randomized, and controlled studies are necessary to determine the origin of the defects that make conception more difficult in the case of endometriosis and adenomyosis.

Concentrations of matrix metallopeptidase 9, interleukin 4, and interleukin 8 in follicular fluid, and the results of in vitro fertilization

Objective

Cytokines and enzymes in follicular fluid (FF) may have a crucial role in fertility. This study aimed to analyse the results of in vitro fertilization/embryo transfer (IVF/ET) and compare them with matrix metalloproteinase 9 (MMP-9) and cytokine concentrations in FF.

Methods

This case–control study included 20 randomly selected patients with a positive pregnancy (PPG) test and 20 with a negative pregnancy (NPG) test after IVF/ET. In FF obtained during oocyte retrieval, the concentrations of soluble forms of MMP-9, interleukin 1 (IL-1) alpha, IL-1 beta, interferon gamma, IL-2, IL-4, IL-6, IL-8, and IL-10 were measured. Their effect on the characteristics of follicles, embryos, and the efficiency of IVF and ET were analysed.

Results

High-sensitivity IL-4 concentrations were significantly higher in patients with a PPG test than in those with an NPG test (3.15 ± 3.23 vs 1.91 ± 0.35 pg/mL). The number of top-quality embryos achieved was significantly higher in patients with a PPG test than in those with an NPG test (2.6 ± 1.39 vs 1.75 ± 1.21), and they were negatively correlated with IL-8 concentrations in FF.

Conclusion

Further research on the role of IL-4 and IL-8 in FF is required to establish any clinical benefit of determining their concentrations in FF of infertile women.

Huayu Jiedu Fang Protects Ovarian Function in Mouse with Endometriosis Iron Overload by Inhibiting Ferroptosis

Endometriosis (EM) is a common chronic inflammatory disease in women. Sampson's retrograde menstruation theory is the most widely accepted theory of EM pathogenesis. The periodic bleeding of ectopic lesions is an important pathological feature of this disease, and the occurrence and progression of EM are closely associated with the iron overload caused by ectopic lesions. However, animal models that simulate menstrual-blood reflux and hemorrhage from EM lesions are lacking. In this study, we performed intraperitoneal injection of endometrial fragments and periodic intraperitoneal blood injection to simulate the real cause and disease state of EM and successfully constructed a mouse model of EM iron overload. Our research found that the number, size, and degree of adhesion of EM lesions in the iron-overload model mouse were significantly higher than those in the model mouse. Moreover, the iron concentration in the abdominal fluid and ovary significantly increased, and the level of malondialdehyde (MDA) in the ovary increased. Conversely, GPX4, GSH, and other anti-ferroptosis-related proteins were downregulated, proving the occurrence of ferroptosis. Huayu Jiedu Fang (HYJDF) is an empirical prescription for EM treatment. This study combined animal experiments, UHPLC-QE-MS analysis, and network pharmacology to analyze whether HYJDF can inhibit ferroptosis to slow down the progression of EM and protect ovarian function. Based on the constructed iron-overload model, HYJDF can reduce the volume of EM lesions and the degree of adhesion, downregulate the total iron concentration in the peritoneal fluid and ovary, upregulate GPX4 expression and GSSG in the ovary, downregulate the level of MDA in the ovary, and promote the development of follicles. We further confirmed that HYJDF can inhibit the progression of EM disease and improve the ovarian function of the model mouse by inhibiting ferroptosis. Finally, through UHPLC-QE-MS and network pharmacology analysis, the natural compounds in HYJDF were identified and verified and the regulatory effect of HYJDF on the EM ferroptosis pathway through the IL-6/hepcidin pathway was preliminarily elucidated.

Association between polyunsaturated fatty acid intake and infertility among American women aged 20-44 years

Background

Infertility is a nationwide public health priority in the U.S. However, few studies have investigated the effects of dietary intake of polyunsaturated fatty acids (PUFAs) on female infertility. This study explored the association between PUFA intake and risk of infertility.

Methods

A total of 1,785 women aged 20-44 years from three National Health and Nutrition Examination Survey cycles (2013-2018) were included in this cross-sectional study. The intake of PUFAs was obtained from a 24-h dietary interview on two separate days with a 3-10-day interval, and nutrient residue models were used. Fertility status was assessed by positive response to two relative questions via a questionnaire. Logistic regression models were used and some covariates were adjusted.

Results

Among all the participants, 340 (19.05%) women suffered from infertility. The intake of docosahexaenoic acid (DHA) (OR = 0.998, 95% CI 0.998, 0.009) was slightly related to the risk of infertility. In contrast, women with higher α-linolenic acid (ALA) (OR = 1.416, 95% CI 1.138, 1.763) and linoleic acid (LA) intake (OR = 1.020, 95% CI 1.002, 1.038) presented with a relatively higher risk of primary infertility. Furthermore, in 20-34-year-old women, higher omega-6/omega-3 was significant associated with the risk of infertility (OR = 1.002, 95%CI 1.000, 1.005).

Conclusions

Our results suggest that PUFA intake is only slightly associated with infertility. The higher the DHA intake, the lower the risk of infertility regardless of age. In women with primary infertility, ALA and LA has negative effect.

Evaluation of the relationship between miR-1271 and GRB2 gene in endometriosis

BACKGROUND

Endometriosis is a common gynecological condition with a substantial economic burden on society. It is known that both genetic and environmental factors are contributing to the phenotypic development of the disease. MicroRNAs have a vital role in the pathogenesis of endometriosis. miR-1271 and its direct target gene, GRB2 (growth factor receptor-bound protein 2), expression have been studied in gynecologic cancers, while their role in endometriosis has not been studied.

OBJECTIVE

We measured miR-1271 and GRB2 gene expression in the eutopic and ectopic tissues of patients (endometrial tissues) in contrast to the control samples from healthy women.

MATERIALS AND METHODS

In this study, a total of 45 samples (15 control samples, 15 eutopic samples and 15 ectopic samples) were collected. We used qRT-PCR (quantitative polymerase chain reaction) to evaluate the expression levels of the miR-1271 and GRB2 gene.

RESULTS

We observed inverse expression of miR-1271 and GRB2 gene. MiR-1271 expression was significantly reduced in patients with endometriosis compared with healthy women. While there was a noticeable increase in the expression level of its target gene, GRB2, in tissues of endometriosis patients compared with normal control samples.

CONCLUSION

We have shown an inverse relationship between the reduction of miR-1271 expression level and increase in the expression level of GRB2, therefore, increased GRB2 expression in endometriosis tissues can be due to decreased expression of this microRNA. Our findings suggested that miR-1271 maybe play a role as a biomarker in the diagnosis of patients with endometriosis.

Endometriosis: A Disease with Few Direct Treatment Options

Endometriosis is a gynecological condition characterized by the growth of endometrium-like tissues inside and outside the pelvic cavity. The evolution of the disease can lead to infertility in addition to high treatment costs. Currently, available medications are only effective in treating endometriosis-related pain; however, it is not a targeted treatment. The objective of this work is to review the characteristics of the disease, the diagnostic means and treatments available, as well as to discuss new therapeutic options.

Infertile women with endometriosis possess differences in cytokine levels in various tissues

OBJECTIVE

(1) To characterize the cytokine expression profiles of endometriosis related infertile women in comparison to fertile women with endometriosis; (2) to investigate the correlation of the cytokine levels from different tissues.

METHODS

100 stage IV endometriosis patients were recruited and grouped by infertility status (n = 50, separately). Concentrations of TNF-α, TGF-β1, IL-10, and IL-17A from the serum, peritoneal fluid (PF), eutopic, and ectopic endometrium samples were measured.

RESULTS

(1) In the infertile group, the concentrations of IL-10 within serum, PF and eutopic endometrium were all significantly higher (p = .022 and <.01, .013, respectively), the levels of TGF-β1 in serum and eutopic endometrium samples were both higher (p = .025 and p < .01), the levels of IL-17A in the PF, eutopic, and ectopic endometrium were all lower (p < .01, all). (2) Significant positive correlation was observed between IL-17A from PF and the ectopic endometrium (p = .014), IL-17A from PF and eutopic endometrium (p < .01). The PF IL-10 levels positively correlated with those in the serum (p = .007).

CONCLUSIONS

This is the first study comparing the levels of cytokines within four different tissues of endometriosis women with or without infertility. The study revealed that endometriosis-related infertile women possess significant differences in cytokine levels in comparison to fertile women with endometriosis. The levels of inflammatory factors from different tissues had certain positive correlations. Infertility may indicate the progress of the disease.

Study on the Mechanism of Shenjing Guben Prescription Regulating PI3K and NRF2 Signaling Pathway in the Treatment of Immune Infertility

Objective

To explore the mechanism of Shenjing Guben prescription (SP) in the treatment of immune infertility by regulating PI3K-NRF2/p38 signal pathway.

Methods

60 adult male SD rats were randomly divided into control group (NC group), ACN group, low concentration AP intervention group (low group), middle concentration SP intervention group (middle group), and high concentration SP intervention group (high group). 12 rats in each group were administered by gavage once a day, 6 days/w, and the rats were killed after 28 days. Bilateral testis and epididymis were removed and weighed and organ coefficients were calculated, and testicular histopathological sections were prepared to evaluate the changes of testicular tissue structure. The relative expression levels of PI3K, MKK7, JNK, p38 mRNA, and protein in testis were measured by QRT-PCR and western blot.

Results

(1) Compared with the control group, the proportion of grade A and B sperms in ACN group increased significantly, and the proportion of grade D sperm decreased significantly (P < 0.05). After SP intervention, compared with ACN group, there was no significant difference in the proportion of sperm at all levels in low, medium, and high SP intervention groups (P > 0.05). (2) Compared with the control group, the sperm VCL, VSL, VAP, and mad in ACN group increased significantly, and the BCF decreased significantly (P < 0.05). After SP intervention, compared with ACN group, there was no significant difference in sperm motility parameters among low, medium, and high SP intervention groups (P > 0.05). (3) Compared with the control group, the activities of AKP and SDH in testicular tissue of rats in ACN group decreased significantly (P < 0.05). After SP intervention, compared with ACN group, AKP activity increased significantly and LDH activity decreased significantly in low, medium, and high SP intervention groups (P < 0.05). (4) Compared with the control group, the expression levels of PI3K, p-PI3K, MKK7, p-MKK7, JNK, p-JNK, p38, and p-p38 proteins and the ratios of p-JNK/JNK and p-p38/p38 increased in the testis of ACN group (P < 0.05). After SP intervention, compared with ACN group, the protein expression levels of PI3K, p-PI3K, MKK7, p-MKK7, JNK, p-JNK, p38, and p-p38 in testicular tissue of SP intervention group decreased, and the ratio of p-JNK/JNK and p-p38/p38 decreased (P < 0.05).

Conclusion

SP can reduce the oxidative stress of testis induced by ACN and inhibit the activation of PI3K-NRF2/p38 signal pathway.

Progesterone-induced blocking factor 1 and cytokine profile of follicular fluid of infertile women qualified to in vitro fertilization: The influence on fetus development and pregnancy outcome

Introduction: Progesterone is essential for both the initiation and the maintenance of pregnancy. The immunological effects of progesterone are mediated by the progesterone-induced blocking factor (PIBF), which is an immunomodulatory factor with anti-abortive properties. The aim of the research was to establish the cytokine profile and PIBF1 concentration in follicular fluid (FF) of patients undergoing in vitro fertilization (IVF).

Methods: Seventy-eight patients who qualified for IVF underwent a detailed medical interview, including the course of fertility treatment and physical, gynecological, and cytological examinations. The concentration of PIBF1, IL-18, IL-2, IL-4, IL-6, IL-10, interferon-γ (IFN-γ), IL-1α, IL-1β, IL-5, IL-8, and IL-15 in FF during ovarian puncture was measured using commercially available ELISA kits.

Results: IL-1 beta concentration was lower in the FF of patients with successful IVF. IL-8 concentration in FF correlated with the number of cumulus-oocyte complexes (COC-1), metaphase II (MII), and top-quality embryos. PIBF1 concentration had a positive correlation with the number of MII and top-quality embryos. IL-2 and IL-6 concentrations were positively correlated with the number of COC-1 and MII. An important parameter in assessing the chances of successful IVF is the number of top-quality embryos achieved.

Conclusion: Higher PIBF1 concentration in FF may indicate a greater possibility of successful IVF due to the higher number of top-quality embryos. IL-1 beta concentration was found to be lower in the FF of patients with successful IVF. Therefore, PIBF1 and IL-1 beta in FF could be candidates for a marker of successful IVF.

Immunology and Immunotherapy of Endometriosis

Endometriosis is one of the most common gynecological and systemic diseases, with a remarkable immune background. Patients suffer from pain and fertility reduction. Due to the distinct immune component, an immunotherapeutic approach may gain importance in the future. In endometriosis, shifts in the cell fractions of the immune system are well known. Moreover, hypoxia concomitant with inflammation causes a disturbed immune response. The removal of endometriosis has a therapeutic effect, normalizes the immune disorders, and remains the most effective causative treatment in terms of pain and infertility. A key issue is whether a similar effect can be achieved for fertility with non-invasive immunotherapy where surgery is inadvisable or cannot be performed for various reasons. Numerous immunotherapy trials, including vaccines, were conducted on animals only, although the research is encouraging. Among the promising methods of non-specific immunotherapy is the administration of an ethiodized oil contrast. Moreover, due to the significant successes of immunotherapy in oncology, the possibility of immunotherapy affecting NK cells has been postulated. NK cells are responsible for the surveillance and apoptosis of ectopic cells. Expanding the arsenal of endometriosis treatment by immunotherapy is promising due to the significant contribution of immunological factors and the limitations of current treatment methods.

Maternal-Fetal Outcomes in Women with Endometriosis and Shared Pathogenic Mechanisms

The connection between endometriosis and pregnancy outcomes is trending among the research topics. Until recently, endometriosis and its painful symptomatology were considered to be alleviated by pregnancy. However, these beliefs have shifted, as emerging literature has demonstrated the role of this condition in affecting pregnancy evolution. The underlying pathogenesis of endometriosis is still poorly understood, all the more when pregnancy complications are involved. Debatable opinions on endometriosis associated with obstetric complications exist because of the potential bias resulting from the heterogeneity of preceding evidence. This review aims to evaluate the connection between endometriosis and adverse pregnancy outcomes and their shared pathogenic mechanisms. We searched PubMed and EMBASE and focused on the studies that include placenta praevia, premature rupture of membranes, spontaneous preterm birth, gestational hypertension, preeclampsia, obstetric hemorrhages (ante- and postpartum bleeding, abruptio placentae), miscarriage, stillbirth, neonatal death, gestational diabetes mellitus, gestational cholestasis, small for gestational age, and their association with endometriosis. Not only the risks of emergence were highlighted, but also the pathogenic connections. Epigenetic alterations of some genes were found to be mirrored both in endometriosis and obstetric complications. This review issues a warning for providing increased attention to pregnant women with endometriosis and newborns as higher risks of preeclampsia, placental issues, and preterm deliveries are associated.

Function of Follicular Cytokines: Roles Played during Maturation, Development and Implantation of Embryo

A balance within the immune system is necessary for the proper development of ovarian follicles. Numerous cytokines were detected in follicular fluid, the role of which in reproductive physiology seems crucial. They influence the development and maturation of the follicle, ovulation, and corpus luteum formation, as well as embryo implantation and maintenance of pregnancy. The analysis of follicular fluid requires its collection by puncturing of the ovary, which is usually executed in connection with various gynaecological procedures. When interpreting such test results, clinical indications for a given procedure and the method of patient preparation should be taken into account. This review revealed the results of currently available studies on the concentration of pro-inflammatory cytokines in follicular fluid in various forms of infertility. Additionally, it presented cytokines, whose concentration has a significant impact on the size of ovarian follicles, their number, the effectiveness of in vitro fertilisation, development of the embryo, and chances of correct implantation. Despite the many recent publications, the knowledge of follicular fluid immunology in the context of reproductive pathology is superficial and further research is required to extensively understand the roles of individual cytokines in reproductive pathology. In the future, this knowledge may enable patients’ individual qualifications to individual methods of infertility treatment, as well as the possible adjustment of the treatment regimen to the patient’s immune profile.

A Brief Analysis of Tissue-Resident NK Cells in Pregnancy and Endometrial Diseases: The Importance of Pharmacologic Modulation

NK cells are lymphocytes involved in the innate and adaptative immune response. These cells are located in peripheral blood and tissues with ample functions, from immune vigilant to tolerogenic reactions. In the endometrium, NK cell populations vary depending on age, hormones, and inflammation. When pregnancy occurs, tissue-resident NK cells and conventional NK cells are recruited to protect the fetus, a tolerogenic response. On the contrary, in the inflamed endometrium, various inflammatory cells down-regulate NK tolerance and impair embryo implantation. Therefore, NK cells’ pharmacological modulation is difficult to achieve. Several strategies have been used, from progesterone, lipid emulsions to steroids; the success has not been as expected. However, new therapeutic approaches have been proposed to decrease the endometrial inflammatory burden and increase pregnancy success based on understanding NK cell physiology.

The Impact of New Immunological Therapeutic Strategies on Recurrent Miscarriage and Recurrent Implantation Failure

Maternal-fetal immune dysregulation is one of the risk factors that increases the probability of embryo rejection and reproductive failure. The stimulation of immunological tolerance and suppression of immunological rejection are prerequisites for protecting embryos and preventing immunological attacks. Hence, it appears that immunomodulatory and immunosuppressive therapies can manage reproductive failures by controlling immune cells. The current medical literature has shown that immunotherapy approaches and cell therapy have promising results in improving pregnancy outcomes and live birth rates. These outcomes are obtained by regulating maternal immune responses, and exerting positive effects on human reproductive processes.