Chronic endometritis and infertility

AI-algorithm training and validation for identification of endometrial CD138+ cells in infertility-associated conditions; polycystic ovary syndrome (PCOS) and recurrent implantation failure (RIF)

Background

Endometrial CD138+ plasma cells serve as a diagnostic biomarker for endometrial inflammation, and their elevated occurrence correlates positively with adverse pregnancy outcomes. Infertility-related conditions like polycystic ovary syndrome (PCOS) and recurrent implantation failure (RIF) are closely associated with systemic and local chronic inflammatory status, wherein endometrial CD138+ plasma cell accumulation could also contribute to endometrial pathology. Current methods for quantifying CD138+ cells typically involve laborious and time-consuming microscopic assessments of only a few random areas from a slide. These methods have limitations in accurately representing the entire slide and are susceptible to significant biases arising from intra- and interobserver variations. Implementing artificial intelligence (AI) for CD138+ cell identification could enhance the accuracy, reproducibility, and reliability of analysis.

Methods

Here, an AI algorithm was developed to identify CD138+ plasma cells within endometrial tissue. The AI model comprised two layers of convolutional neural networks (CNNs). CNN1 was trained to segment epithelium and stroma across 28,363 mm2 (2.56 mm2 of epithelium and 24.87 mm2 of stroma), while CNN2 was trained to distinguish stromal cells based on CD138 staining, encompassing 7345 cells in the object layers (6942 CD138- cells and 403 CD138+ cells). The training and performance of the AI model were validated by three experienced pathologists. We collected 193 endometrial tissues from healthy controls (n = 73), women with PCOS (n = 91), and RIF patients (n = 29) and compared the CD138+ cell percentages based on cycle phases, ovulation status, and endometrial receptivity utilizing the AI model.

Results

The AI algorithm consistently and reliably distinguished CD138- and CD138+ cells, with total error rates of 6.32% and 3.23%, respectively. During the training validation, there was a complete agreement between the decisions made by the pathologists and the AI algorithm, while the performance validation demonstrated excellent accuracy between the AI and human evaluation methods (intraclass correlation; 0.76, 95% confidence intervals; 0.36-0.93, p = 0.002) and a positive correlation (Spearman's rank correlation coefficient: 0.79, p < 0.01). In the AI analysis, the AI model revealed higher CD138+ cell percentages in the proliferative phase (PE) endometrium compared to the secretory phase or anovulatory PCOS endometrium, irrespective of PCOS diagnosis. Interestingly, CD138+ percentages differed according to PCOS phenotype in the PE (p = 0.03). On the other hand, the receptivity status had no impact on the cell percentages in RIF samples.

Conclusion

Our findings emphasize the potential and accuracy of the AI algorithm in detecting endometrial CD138+ plasma cells, offering distinct advantages over manual inspection, such as rapid analysis of whole slide images, reduction of intra- and interobserver variations, sparing the valuable time of trained specialists, and consistent productivity. This supports the application of AI technology to help clinical decision-making, for example, in understanding endometrial cycle phase-related dynamics, as well as different reproductive disorders.

An insight into the vaginal microbiome of infertile women in Bangladesh using metagenomic approach

Introduction

The dysbiosis of vaginal microbiota is recognized as a potential underlying factor contributing to infertility in women. This study aimed to compare the vaginal microbiomes of infertile and fertile women to investigate their relationship with infertility.

Methods

Metagenomic analysis was conducted on samples from 5 infertile and 5 fertile individuals using both amplicon 16S and metagenomics shotgun sequencing methods.

Results and discussion

In the infertile group, the bacterial community was primarily represented by three major bacterial genera: Lactobacillus (79.42%), Gardnerella (12.56%) and Prevotella (3.33%), whereas, the fertile group exhibited a more diverse composition with over 8 major bacterial genera, accompanied by significantly reduced abundance of Lactobacillus (48.79%) and Gardnerella (6.98%). At the species level, higher abundances of L. iners, L. gasseri and G. vaginalis were observed in the infertile group. Regarding the microbiome composition, only one fertile and two infertile subjects exhibited the healthiest Community State Types, CST-1, while CST-3 was observed among two infertile and one fertile subject, and CST-4 in three other fertile and one infertile subject. Overall, alpha diversity metrics indicated greater diversity and lower species richness in the control (fertile) group, while the infertile group displayed the opposite trend. However, beta-diversity analysis did not show distinct clustering of samples associated with any specific group; instead, it demonstrated CST-type specific clustering. Shotgun metagenomics further confirmed the dominance of Firmicutes, with a greater abundance of Lactobacillus species in the infertile group. Specifically, L. iners and G. vaginalis were identified as the most dominant and highly abundant in the infertile group. Fungi were only identified in the control group, dominated by Penicillium citrinum (62.5%). Metagenome-assembled genomes (MAGs) corroborated read-based taxonomic profiling, with the taxon L. johnsonii identified exclusively in disease samples. MAG identities shared by both groups include Shamonda orthobunyavirus, L. crispatus, Human endogenous retrovirus K113, L. iners, and G. vaginalis. Interestingly, the healthy microbiomes sequenced in this study contained two clusters, Penicillium and Staphylococcus haemolyticus, not found in the public dataset. In conclusion, this study suggests that lower species diversity with a higher abundance of L. iners, L. gasseri and G. vaginalis, may contribute to female infertility in our study datasets. However, larger sample sizes are necessary to further evaluate such association.

Irisin as an emerging target in the regulation of reproductive functions in health and disease

Germ cells are highly conserved in the gonads, nurtured to either develop into a gamete or self-renew into a stem cell reserve. Preserving the germ cell pool and protecting the reproductive organs is essential for maintaining an individual's fertility. Several factors, including a sedentary lifestyle, pollutants, hormonal disruption, drugs, and a disease condition, have been shown to impair normal reproductive function. Irisin has recently been identified as an adipomyokine involved in modulating physiological functions based on the body's metabolic status. It is being studied for its role in various functions, including fertility. Findings show the localization of irisin in various parts of the reproductive axis, with the highest levels observed during puberty and pregnancy. This raises questions about its role and function in reproduction. Studies support irisin's role in protecting against disease-induced reproductive abnormalities and infertility. Therefore, the current review focuses on how irisin influences spermatogenesis and ovarian follicular development and plays a significant role in indirectly preserving the germ cell pool by protecting the gonads against oxidative stress and inflammation.

Exploring the effectiveness of endometrial receptivity array and immune profiling in patients with multiple implantation failure：A retrospective cohort study based on propensity score matching

This study aimed to evaluate the effectiveness of the endometrial receptivity array (ERA), endometrial immune profiling, and a combination of both in improving the pregnancy outcomes for multiple implantation failure patients. According to patients' willingness, 1429 women who incurred at least two or more consecutive implantation failures in IVF/ICSI treatment opted for frozen embryo transfer and were divided into four groups: 'No test', 'Immune Profiling', 'ERA' and 'ERA+ Immune Profiling'. Women in three test groups underwent timed endometrial biopsy for ERA, immune profiling, a combination of both. We observed the overall incidence rates of the displaced window of implantation (WOI) and endometrial immune dysregulation were 75.14% and 79.29%, respectively. After 1:1 propensity score matching (PSM), our data revealed that the 'ERA' and 'ERA + Immune Profiling' groups demonstrated significantly higher rates of biochemical, clinical, ongoing pregnancy, and implantation compared to the 'No test' group (p < 0.01). The 'Immune Profiling' group showed a higher implantation rate compared to 'No test' group (p < 0.05). Furthermore, when comparing three test groups, the 'ERA + Immune Profiling' group exhibited notably higher rates of clinical and ongoing pregnancy compared to the 'Immune Profiling' group (p < 0.017). However, there was no association between endometrial immune profiling and ERA phases, and their results did not differ between embryo implantation and non-implantation in these patients. Our findings underline the increased implantation rates by use of ERA and endometrial immune profiling in patients with multiple implantation failure, either individually or corporately. Moreover, a combination of both could improve their pregnancy outcomes significantly.

Platelet rich plasma alleviates endometritis induced by lipopolysaccharide in mice via inhibiting TLR4/NF-κB signaling pathway

BACKGROUND

Endometritis is an inflammatory reaction of the lining of uterus, leading to the occurrence of infertility. Platelet rich plasma (PRP) has been proven to exhibit extremely effective for the treatment of endometrium-associated infertility, but the mechanism of its prevention for endometritis remains unclear.

OBJECTIVE

The present study aimed to investigate the protective effect of PRP against endometritis induced by lipopolysaccharide (LPS) and elucidate the mechanism underlying these effects.

METHODS

Mouse model of endometritis was established by intrauterine perfusion of LPS. PRP intrauterine infusion was administered at 24 h after LPS induction. After another 24 h, the uterine tissues were harvested to observe histopathological changes, production of proinflammatory cytokines, variation of the Toll-like receptor 4/nuclear factor κB (TLR4/NF-κB) signaling pathways, and validated the anti-inflammatory effect of PRP. The myeloperoxidase (MPO) activity and concentration of nitric oxide (NO) were determined using assay kit. Proinflammatory chemokines (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6)) were measured by ELISA and Real-Time PCR. The activity of TLR4/NF-κB pathway in uterine tissues was measured by Western blotting.

RESULTS

Hematoxylin-eosin staining (H&E) appeared that PRP remarkably relieved the impairment of uterine tissues. Detection of MPO activity and concentration of NO revealed that PRP treatment distinctly mitigated infiltration of inflammatory cells in mice with endometritis induced by LPS. PRP treatment significantly affected the expression of TNF-α, IL-1β, and IL-6. PRP was also found to suppress LPS-induced activation of TLR4/NF-κB pathway.

CONCLUSION

PRP effectively alleviates LPS-induced endometritis via restraining the signal pathway of TLR4/NF-κB. These findings provide a solid foundation for PRP as a potential therapeutic agent for endometritis.

Impact of a positive Chlamydia trachomatis serology on cumulative IVF live birth rate

RESEARCH QUESTION

Does positive Chlamydia trachomatis serology have an impact on the cumulative live birth rate from IVF?

DESIGN

A retrospective matched cohort study compared women with positive Chlamydia trachomatis serology (group A) who underwent IVF treatment between January 2016 and December 2021 with a control group of women with negative Chlamydia trachomatis serology (group B). The main outcome measures were the cumulative live birth rate per IVF cycle and the live birth rate per embryo transfer. Secondary outcomes were the cumulative rates of clinical pregnancy, ectopic pregnancy and pregnancy loss calculated per IVF cycle and per embryo transfer.

RESULTS

A total of 151 women in group A were matched 1:2 to 302 women in group B, representing 220 and 440 IVF cycles, respectively. Women with a history of Chlamydia trachomatis infection had a significantly higher rate of tubal obstruction (P < 0.001), excluded or operated hydrosalpinx (P = 0.002) and/or history of chronic endometritis (P < 0.001). There were no statistically significant differences between the two groups in the mean number of mature oocytes retrieved, fertilization rate or implantation rate. The IVF cumulative live birth rate per cycle was similar in the two groups (36.7% in group A versus 34.9% in group B, P = 0.692). The cumulative rates of clinical pregnancy, pregnancy loss, biochemical pregnancy and ectopic pregnancy were comparable between the two groups.

CONCLUSION

Positive Chlamydia trachomatis serology has no impact on IVF pregnancy outcomes.

Pregnancy outcomes in patients with familial Mediterranean fever: systematic review and meta-analysis

OBJECTIVE

The relationship between FMF and pregnancy outcomes remains unclear. This systematic review and meta-analysis aimed to clarify this association.

METHODS

Electronic databases-PubMed, Web of Science, Cochrane, and EMBASE-were searched on 20 December 2022, using specific search terms. Case-control, cohort, and randomized clinical trial studies comparing patients with FMF and healthy controls were considered eligible. We excluded systematic reviews, meta-analyses, case series with fewer than five cases, republished articles without new findings on pregnancy outcomes, studies targeting paternal FMF, and those not published in English. The results were summarized in the form of odds ratios (ORs) and 95% CIs, using a random-effects model. This study was registered in the University hospital Medical Information Network Clinical Trials Registry (Japan) as UMIN000049827.

RESULTS

The initial electronic search identified 611 records, of which 9 were included in this meta-analysis (177 735 pregnancies, 1242 with FMF, and 176 493 healthy controls). FMF was significantly associated with increased odds of preterm deliveries (OR, 1.67; 95% CI, 1.05-2.67; I2 = 22%) and insignificantly associated with increased odds of fetal growth restriction (OR, 1.45; 95% CI, 0.90-2.34; I2 = 0%) and hypertensive disorders during pregnancy (OR, 1.28; 95% CI, 0.87-1.87; I2 = 0%).

CONCLUSION

FMF was significantly associated with preterm delivery and insignificantly associated with fetal growth restriction and hypertensive disorders. All of the included studies were observational studies. Treatment characteristics were not fully collected from the articles, and further analysis of treatments for FMF in pregnancy is still warranted.

Pregravid preparation of women with chronic endometritis in IVF cycles

OBJECTIVE

Aim: of our study was to improve the pregravid preparation of women with chronic endometritis to develop individual approaches to overcoming infertility, taking into account the state of endometrium.

PATIENTS AND METHODS

Materials and Methods: The study included 90 women (main group, n=90), 28 to 38 years with an anatomically normal uterus and chronic endometritis (CE). Patients were divided into 2 groups: group I - 45 women with CE who received conventional treatment; group II - 45 women with CE who received pregravid preparation by subendometrial injections of Platelet-Rich Plasma (PRP).

RESULTS

Results: At the first stage of study, the ART statistical reports from 2015 to 2022 were analyzed at the Medical Center of Reproductive Health ≪Damia≫, (Ivano-Frankivsk). Analysis of the vaginal flora parameters before treatment at the first stage revealed the presence of conditionally pathogenic flora in culture from the cervical canal (Candida albicans - 2.4%, Escherihia coli - 4.8%, Staphylococcus epidermidis - 6.2% Enterococcus faecalis - 6.9%), and was evidence of a possible recurrence of inflammation during gestation. In the age category, the groups of patients were homogeneous, with no significant differences by the level of AMH and the level of CD 138. Biochemical pregnancy be present in 20 patients (44.4%) of group I and 28 (62.2%) of group II. Fertility within a year after the end of therapy was restored with the proposed method of therapy in most women (51.1%), in the comparison group this number was 11.1% lower. Pregnancy rate between the groups (I and II) did not differ significantly. The number of live births in group II - 19 births (42.2%) - was 2 times higher than I group (9 (20.0%), P<0.05). The most common complication for women in the comparison groups was early pregnancy loss. Among 18 (40.0%) clinical pregnancies of group I, 8 women (17.8%) had early miscarriage, 1 ectopic pregnancy (2.2%), while in group II clinical pregnancy be present in 23 women (51.1%). The number of terminated pregnancies was two times lower than in the first group (8.9% vs. 17.8%, P<0.05).

CONCLUSION

Conclusions: Chronic endometritis is one of the main causes of pregnancy loss after in vitro fertilization. Patients of the second group were treated with the proposed method of subendometrial injections with Platelet-Rich Plasma (PRP), prepared from autologous blood, is an effective method of preparing the endometrium for embryo transfer and can increase the number of live births in patients with chronic endometritis.

Hysteroscopic features suggestive of chronic endometritis: a systematic review

The purpose of this systematic review is to identify common hysteroscopic findings suggestive of endometritis, chronic or subclinical, based on current scientific evidence. Data sources were MEDLINE, Embase, PubMed and other sources of grey literature. Four (4) authors independently selected studies addressing hysteroscopic detection of CE based on specific and clearly stated hysteroscopic criteria. The diagnosis was confirmed by histologic assessment, as stated in the materials and methods of these studies included. The initial search identified 599 studies, of which 21 met the inclusion criteria. Significant heterogeneity among published studies on Chronic endometritis (CE) remains the main limitation in performing a metanalysis and further analysis of diagnostic accuracy on the subject. Hysteroscopy is an important diagnostic tool in cases of chronic endometritis when accompanied by endometrial biopsies. Clinicians relate hyperaemia and endometrial oedema with chronic endometritis while more than half include micropolyposis as a pathognomonic feature of this subclinical condition. Micropolyps, stromal oedema, haemorrhagic spots, strawberry aspect, and hyperaemia are proposed as adequate indicators of hysteroscopic evidence of CE according to the literature. The impact of CE in long-term reproductive outcomes remain unclear, thus clinicians ought to communicate this to the patients and provide treatment where clinically appropriate. In addition, we present hysteroscopic images of histologically confirmed CE cases that could play the role of a hysteroscopic atlas.

Bacterial Vaginosis: Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/028, June 2023)

Aim This official guideline was coordinated and published by the DGGG, OEGGG and SGGG with the involvement of additional professional societies. The aim of the guideline is to evaluate the relevant literature and use it to provide a consensus-based overview of the diagnosis and management of bacterial vaginosis. Methods This S2k-guideline was developed by representative members from different medical professional societies on behalf of the guidelines commission of the above-listed societies using a structured consensus process. Recommendations This guideline provides recommendations on the diagnosis, management, counselling, prophylaxis, and other aspects related to bacterial vaginosis.

Benefits of antibiotics and the optimal time interval between biopsy and the next embryo transfer in patients with chronic endometritis

This study evaluated the effects of antibiotics on the implantation rate (IR) as well as the optimal time interval from endometrial biopsy to subsequent embryo transfer (ET) to explore proper chronic endometritis (CE) management. We retrospectively analyzed the clinical data of patients who had failed 1 or 2 ET cycles and underwent hysteroscopy. CE was diagnosed when 3 or more cluster of differentiation138 - positive plasma cells were found per high-power field. We divided the patients into 3 groups: those with CE who received antibiotics (group 1), those with CE who did not receive antibiotics (group 2), and those without CE (group 3). We found that IR was significantly higher in Group 1 than in Group 2. Furthermore, while the IR in Groups 1 and 3 was significantly higher when the time interval was < 6 months than when the time interval was > 6 months, there were no significant differences in the IR when the time interval was < 2 months or ≥ 2 months but < 6 months. Postbiopsy oral antibiotic therapy significantly improved IR in patients with CE, whereas increasing the time interval from biopsy to ET reduced IR. This study may help to find a higher potential for success in the medical management of patients with CE.

Selenomethionine protects against Escherichia coli-induced endometritis by inhibiting inflammation and necroptosis via regulating the PPAR-γ/NF-κB pathway

Endometritis, inflammation of the endometrium, is a major cause of subfertility in women. Selenomethionine (SeMet)is known to exert anti-inflammatory activity. We aimed to verify the protective roles of SeMet on Escherichia coli (E.coli)-induced endometritis. The extent of uterus damage was assessed by detecting histopathology and inflammatory mediators. The results revealed that SeMet significantly prevented E.coli-induced endometritis by attenuating uterine histopathology and inflammatory cytokine production. E.coli-induced MPO activity and MDA content were inhibited by SeMey. E.coli-induced ZO-1 and occludin were upregulated by SeMet. E.coli-induced necroptosis was also inhibited by SeMet. Additionally, E.coli-induced NF-κB activation was alleviated by SeMet. PPAR-γ expression was upregulated by SeMet. Notably, the protective effects of SeMet on endometritis were abolished by a PPAR-γ inhibitor. In conclusion, SeMet inhibits E.coli-induced endometritis by attenuating inflammation and necroptosis, which is mediated by the PPAR-γ/NF-κB signaling pathway.

Immune Cell Functionality during Decidualization and Potential Clinical Application

Due to a vast influx in the secretory phase of the menstrual cycle, leukocytes represent 40-50% of the decidua at the time of implantation. Their importance for the implantation, maintenance of pregnancy, and parturition are known yet not fully understood. Thus, in idiopathic infertility, decidual immune-related factors are speculated to be the cause. In this review, the immune cell functions in the decidua were summarized, and clinical diagnostics, as well as interventions, were discussed. There is a rising number of commercially available diagnostic tools. However, the intervention options are still limited and/or poorly studied. In order for us to make big steps towards the proper use of reproductive immunology findings, we need to understand the mechanisms and especially support translational research.

Follicular helper T lymphocytes in the endometria of patients with reproductive failure: Association with pregnancy outcomes and inflammatory status of the endometria

PROBLEM

The phenotypes and functions of B and CD4⁺ T-helper cell subsets during chronic inflammation of the endometria remain largely unexplored. This study aimed to investigate the characteristics and functions of follicular helper T (Tfh) cells to understand the pathological mechanisms of chronic endometritis (CE).

METHOD OF STUDY

Eighty patients who underwent hysteroscopic and histopathological examinations for CE were divided into three groups-those with positive results for hysteroscopy and CD138 staining (DP), negative results for hysteroscopy but positive CD138 staining (SP), and negative results for hysteroscopy and CD138 staining (DN). The phenotypes of B cells and CD4⁺ T-cell subsets were analyzed using flow cytometry.

RESULTS

CD38⁺ and CD138⁺ cells were mainly expressed in the non-leukocyte population of the endometria, and the endometrial CD19⁺ CD138⁺ B cells were fewer than the CD3⁺ CD138⁺ T cells. The percentage of Tfh cells increased with chronic inflammation in the endometria. Additionally, the elevated percentage of Tfh cells correlated with the number of miscarriages.

CONCLUSIONS

CD4⁺ T cells, particularly Tfh cells, may be critical in chronic endometrial inflammation and affect its microenvironment, thereby regulating endometrial receptivity, compared to B cells.

Adverse impact of CD138+ cells in proliferative-phase endometrium on pregnancy outcomes in fresh IVF/ICSI cycles

To evaluate the impact of Syndecan-1 (CD138) in proliferative-phase endometrium on pregnancy outcomes in fresh in vitro fertilization (IVF)/ intracytoplasmic sperm injection (ICSI) cycles. This retrospective cohort study contained 273 patients who underwent IVF/ICSI with fresh embryo transfer following an endometrial curettage from January 2020 to May 2022. Endometrial curettage was performed on all patients within 3 to 5 days following menstruation and endometrial tissue was acquired for detection of plasma cells by immunohistochemistry. Subsequent pregnancy outcomes of all cycles were traced and analyzed. A total of 149 patients became pregnant (i.e., pregnant group) in the fresh transfer IVF/ICSI cycles and 124 did not become pregnant (i.e., nonpregnant group). The number of CD138 + cells/ high-power field (HPF) of the nonpregnant group was significantly higher than the pregnant group (2.36 ± 4.24 vs 1.31 ± 3.41, P = .008). The cut off value of CD138 + cells/HPF was 2 by receiver operating characteristic curve analysis, with an area under the receiver operating characteristic curve of 0.572. Compared with the negative group (i.e., CD138 + cells/HPF < 2, n = 204), the positive group (i.e., CD138 + cells/HPF ≥ 2, n = 69) had a significantly lower clinical pregnancy rate (71.8% vs 40.6%, P < .001). The clinical pregnancy rate revealed a gradually decreasing trend with the increase in CD138 + cells. Proliferative-phase endometrial CD138 + cells may be an adverse indicator for pregnancy outcomes in fresh IVF/ICSI cycles, with a certain value in predicting non-pregnancy. Pregnancy outcome was poor when CD138 + cells/HPF ≥ 2 in the endometrium and may worsen with the increase in CD138 + cells.

Effect of different antibiotic therapies on the reproductive outcomes of fresh embryo transfer for chronic endometritis: A retrospective cohort study

OBJECTIVE

To investigate the reproductive outcomes by comparing two kinds of antibiotic schemes for chronic endometritis (CE) in infertile women's fresh embryo transfer (FET) cycles and identify subgroups of patients with CE who need long-term antibiotics treatment.

DESIGN

A retrospective cohort study.

SETTING

University-based reproductive medical center.

PATIENT(S)

A total of 492 women with CD138-positive plasmacytes per 10 high-power fields (CD138+/10HPF).

INTERVENTION(S)

Hysteroscopy was performed and endometrial biopsy samples were collected in the proliferative phase. Long-term or short-term antibiotics were administrated. After antibiotics treatment, patients underwent in vitro fertilization (IVF)/ intracytoplasmic sperm injection (ICSI) and received ET.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy rate, clinical pregnancy rate, clinical miscarriage rate.

RESULT (S)

There were no significant differences in pregnancy outcomes between patients with CD138+/10HPF 1-4 (low-grade CE) who received long-term antibiotic therapy and short-term antibiotics groups. Among women with CD138+/10HPF ≥5 (high-grade CE), live birth rate (48.4% vs. 14.7%, p = .001), clinical pregnancy rate (66.7% vs. 35.3%, p = .002) and ongoing pregnancy rate (59.1% vs. 20.6%, p < .001) in the long-term arm were significantly higher than that in the short-term arm. The clinical miscarriage rate (21.0% vs. 58.3%, p = .013) was statistically lower in the long-term antibiotics group, but no statistical differences were found between the two groups in preterm delivery rate.

CONCLUSION

Long-term antibiotics treatment was a sensible choice to improve pregnancy outcomes in women with CD138+/10HPF ≥5 (high-grade CE). The pregnancy outcomes of women with low-grade CE only defined by histological diagnosis were not greatly improved after antibiotic therapy. Therefore, we recommended the proper diagnosis criteria were CD138+/10HPF ≥5 pathologically.

The association between chronic deciduitis and recurrent pregnancy loss

Chronic deciduitis (CD) is defined as the presence of lymphocytes or plasma cells in decidual tissue. CD suggests the presence of chronic endometritis (CE) which is associated with recurrent pregnancy loss (RPL). In this study, we examined the role CD plays in RPL patients with aneuploid and euploid miscarriage. The frequency of CD in 49 RPL patients (22 euploid and 27 aneuploid miscarriages) and 17 control women was assessed and the subsequent live birth rate (LBR) in the presence and absence of CD were compared. When only one CD138-positive endometrial stromal plasma cell (ESPC) was found per high-power field (HPF), we diagnosed small-positive CD (Grade 1). When a cluster of two or more CD138-positive ESPCs was found per HPF, we diagnosed it as CD Grade 2. The prevalence of Grade 1 was 18.2% (4/22) in patients with euploid miscarriage, 37.0% (10/27) in patients with aneuploid miscarriage and 23.5% (4/17) in control women. The prevalence of Grade 2 was 45.5% (10/22) in patients with euploid miscarriage, 55.6% (15/27) in patients with aneuploid miscarriage and 23.5% (4/17) in control women. There was a significant difference in the prevalence of CD (p = 0.015). The LBR of patients with CD was similar to that of patients without CD. CD was associated with RPL, especially in patients with aneuploid miscarriage. However, since there was no difference in the LBR of patients with or without CD in the next pregnancy, it was unclear whether CD was a contributing cause of RPL.

Existence of chronic endometritis and its influence on pregnancy outcomes in infertile women with minimal/mild endometriosis

OBJECTIVE

This study aimed to evaluate the prevalence of chronic endometritis (CE) in women with minimal/mild endometriosis and to analyze whether CE affects their pregnancy outcomes.

METHODS

This retrospective study included 201 infertile women who were diagnosed with minimal/mild endometriosis after undergoing hysteroscopy combined with laparoscopy from January 2016 to December 2018. Immunohistochemistry was used to detect CD138 and CD38, which are specific markers of plasma cells in the endometrial stroma to diagnose CE. Subsequently, we investigated the prevalence of CE and the effects of CE on spontaneous cumulative pregnancy rate, live birth rate, and miscarriage rate within 24 months after surgery.

RESULTS

The prevalence of CE in infertile women with minimal/mild endometriosis was 24.38%. Patients diagnosed with CE showed a significantly lower cumulative pregnancy rate and live birth rate compared with women without CE (46.51% vs. 71.13% [P = 0.004]; 44.19% vs. 63.38% [P = 0.025]). However, the rate of miscarriage in women with CE was also lower than in women without CE (0 vs. 7.04%, P = 0.074).

CONCLUSION

Since CE had an adverse effect on cumulative pregnancy rate and live birth rate in infertile women with minimal/mild endometriosis, we suggested that diagnosis and treatment of CE may improve their pregnancy outcomes.

The alteration of intrauterine microbiota in chronic endometritis patients based on 16S rRNA sequencing analysis

BACKGROUND

Chronic endometritis (CE) is a disease of continuous and subtle inflammation occurring in the endometrial stromal area, which is often asymptomatic or present with non-specific clinical symptoms.

METHODS

This study investigated the composition and distribution of the intrauterine microbiota of 71 patients who underwent hysteroscopy during the routine clinical inspection of infertility. Among them, patients who were diagnosed with chronic endometritis (CE) were allocated into CE group (n = 29) and others into non-CE group (n = 42). There was no significant difference in average age between the two groups (P = 0.19). Uterine flushing fluid was collected by the self-developed cervical trocar uterine cavity sampler and 16S rRNA sequencing was performed.

RESULTS

The alpha diversity in the CE group was significantly higher than that in the non-CE group (P < 0.05). Firmicutes (newly named Bacillota) were the dominant phylum in the non-CE group (72.23%), while their abundance was much lower in the CE group (49.92%), but there was no statistically significant difference between the two groups. The abundances of Actinobacteriota and Cyanobacteria in the CE group were significantly higher than those in the non-CE group (P < 0.05). At the genus level, the abundance of Lactobacillus dominated in all samples, which presented a significantly lower abundance in the CE group (40.88%) than that in the non-CE group (64.22%) (P < 0.05). Correspondingly, the abundance of non-Lactobacillus was higher in the CE group, among which Pseudomonas and Cutibacterium increased significantly (P < 0.01). Moreover, compared with the non-CE group, the pathways involved in arginine and proline metabolism and retinol metabolism were significantly enriched in the CE group (P < 0.05), while the metabolism of lipid and prenyltransferases were significantly decreased in the CE group (P < 0.05).

CONCLUSIONS

A certain microbial community was colonized in the uterine cavity, which was dominated by Lactobacillus. The structure and distribution of intrauterine microbiota in the CE group were different from those in the non-CE group by showing a lower abundance of Lactobacillus, and a significantly higher abundance of Pseudomonas and Cutibacterium. Additionally, the microbial metabolism was altered in the CE group. This study elaborated the alteration of intrauterine microbiota in CE patients, which may contribute to the diagnosis of CE and provide a reference for antibiotic treatment of CE.

Oil-based contrast for hysterosalpingography-regulated Th1/Th2-type cytokines and alleviated inflammation in rats with LPS-induced chronic endometritis

AIM

The chronic endometritis (CE) prevalence in people experiencing infertility is 2.8-56.8%, pregnancy rates in patients with infertility increase after hysterosalpingography with oil-based contrast, but the effect and mechanism are not clear. Here, we analyzed the effects of intrauterine ethiodized poppyseed oil (EPO) bathing on a rat model of CE and the possible underlying mechanism.

METHODS

CE rats were induced by lipopolysaccharide (LPS) exposure, and rats were subjected to intrauterine bathing with EPO or phosphate-buffered saline (PBS) after model verification. Serum and uterus levels of IFN-γ, IL-4, TNF-α, and IL-1β were detected by ELISA kit, and the number of CD138⁺ and CD68⁺ cells and uterine IFN-γ, IL-4, TNF-α, IL-1β, and NF-κB P65 expression were detected by immunohistochemistry after bathing.

RESULTS

LPS exposure induced the typical CE phenotype with CD138⁺ phagocyte infiltration of the endometrial stroma. Compared with PBS bathing, bathing with EPO in CE rats showed decreases in the CD138⁺ and CD68⁺ cells populations and significant decreases in serum and uterine IFN-γ levels, moreover, uterine IL-4 levels were slightly higher, and the IFN-γ/IL-4(Th1/Th2-type cytokine ratio) in the uterus was significantly lower. Local IFN-γ, TNF-α, and NF-κB P65 expression in the endometrium was significantly downregulated, while IL-4 expression was upregulated.

CONCLUSION

Intrauterine oil-based contrast bathing significantly alleviated local inflammation in the rat CE model by downregulating NF-κB P65 expression, reducing IFN-γ (Th1), increasing IL-4 levels (Th2) in the endometrium, and regulating the Th1/Th2-type cytokine trends toward Th2.

Association between hysteroscopic features of chronic endometritis and pregnancy outcomes of patients after in vitro fertilization: a retrospective cohort study

This retrospective cohort study explored the morphological features of chronic endometritis (CE) and pregnancy outcomes during in vitro fertilization (IVF) in women with CE (429) at Yantai Yuhuangding Hospital between January 2017 and September 2018. The primary outcome was the clinical pregnancy rate (CPR). The women displayed haemorrhagic spots (175), hyperaemia (122), micropolyps (75), hyperaemia combined with micropolyps (49) and others (8). The CPR and live birth rate (LBR) were different among the hysteroscopic features of CE in fresh embryo transfer cycles (p = .002, p = .011). The miscarriage and premature birth rates were not significantly different among groups (p > .05). Hyperaemia (0.47 [95% CI, 0.29; 0.77]), micropolyps (0.40 [95% CI, 0.23; 0.72]), hyperaemia combined with micropolyps (0.35 [95% CI, 0.18; 0.69]) and others (0.36 [95% CI, 0.19; 0.69]) were associated with the CPR. In conclusion, the hysteroscopic features of CE are associated with IVF pregnancy outcomes, and there were differences in pregnancy outcomes with different CE hysteroscopic features.IMPACT STATEMENTWhat is already known on this subject? Chronic endometritis (CE) is associated with adverse pregnancy outcomes such as infertility, premature delivery and miscarriage. CE can reduce the success rate of pregnancy and even lead to obstetric and neonatal complications, and is an adverse factor for the success of in vitro fertilization (IVF). There are different types of CE, but their impact on IVF outcomes is unknown.What the results of this study add? The CPR and LBR were different among the hysteroscopic features of CE in fresh embryo transfer cycles (p = .002, p = .011). The miscarriage and premature birth rates were not significantly different among groups (p > .05). After adjustment, the multivariable analysis showed that hyperaemia (OR = 0.47, p = .002), micropolyps (OR = 0.40, p = .002), hyperaemia combined with micropolyps (OR = 0.35, p = .002) and others (OR = 0.36, p = .002) were associated with the CPR among patients with CE.What the implications are of these findings for clinical practice and/or further research? The hysteroscopic features of CE are associated with IVF pregnancy outcomes, and there were differences in pregnancy outcomes with different CE hysteroscopic features. Hence, women with repeated IVF failure should undergo hysteroscopy to examine for the presence of CE and its nature.

Evaluation of implantation markers and immune cell infiltration in endometrial biopsy of female genital tuberculosis

BACKGROUND

Female genital tuberculosis (FGTB) causes infertility in a significant number of females. The immunological impact of tuberculosis on endometrium in infertile females has not been studied before. The present study was designed to evaluate markers related to infiltrating immune cells and implantation in endometrial aspiration from infertile females and correlate with conventional tests and polymerase chain reaction (PCR) for tuberculosis (TB).

METHODS

It was a prospective cohort study with 385 patients out of which IHC was done in 306 over a period of 3 years from 2013 to 2016 in a tertiary care hospital. Women with infertility, 20-35 years of age, without history of pulmonary TB or intake of antitubercular therapy were included. Endometrial samples were subjected to PCR for TB along with microbiological and histological examination for TB. Immunohistochemistry for CD45, CD3, CD20, CD4, CD8, CD68, CD138, Interferon gamma, Interleukin 10 (IL-10) and implantation markers MUC1 and Notch 1 were done on the endometrial samples along with 25 control subjects.

RESULTS

Conventional tests for tuberculosis like staining for acid fast bacilli (AFB), granuloma on histology or culture positivity were seen in 2.61% (6/306; 1.96% had granulomas, 1/306; 0.32% was AFB positive, 2/306; 0.6% were liquid culture positive). PCR was positive in 190/306 (62.09%). CD3, CD20, CD45, CD68, CD4, CD8 and CD 138 expressing infiltrating cells were not significantly related to PCR positive cases. Interferon gamma expressing lymphocytes were significantly higher (38.94%) in PCR positive endometria compared to 26.72% in the PCR negative (p = 0.04). Notch -1 expression correlated significantly with the occurrence of pregnancy. A trend towards high intensity expression of Notch1 was seen in PCR negative cases. MUC-1 expression did not correlate with pregnancy although interferon gamma expression was significantly related to low intensity MUC1 expression.

CONCLUSIONS

Immunohistochemical markers are not reliable tests in diagnosis of FGTB. Notch 1 expression though showing correlation with pregnancy has to be further evaluated with a panel of other implantation markers.

STUDY FUNDING

Indian Council of Medical Research, New Delhi, India.

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.

Inflammation-Related Molecules at the Maternal–Fetal Interface during Pregnancy and in Pathologically Altered Endometrium

The blastocyst expresses paternally derived alloantigens and induces inflammation during implantation. However, it is necessary for the onset of pregnancy. An abnormal response might result in a pathological course of pregnancy or pregnancy failure. On the other hand, a state of maternal immune tolerance is necessary to ensure the normal development of pregnancy by suppressing inflammatory processes. This article discusses recognized mechanisms and the significance of inflammatory processes for embryo implantation and pregnancy establishment. We would also like to present disorders involving excessive inflammatory response and their influence on events occurring during embryo implantation. The chain of correlation between the processes responsible for embryo implantation and the subsequent physiological course of pregnancy is complicated. Many of those interrelationships are still yet to be discovered. Undoubtedly, their recognition will give hope to infertile couples for the emergence of new treatments that will increase the chance of giving birth to a healthy child.

The female reproductive tract microbiotas, inflammation, and gynecological conditions

The intricate interactions between the host cells, bacteria, and immune components that reside in the female reproductive tract (FRT) are essential in maintaining reproductive tract homeostasis. Much of our current knowledge surrounding the FRT microbiota relates to the vaginal microbiota, where ‘health’ has long been associated with low bacterial diversity and Lactobacillus dominance. This concept has recently been challenged as women can have a diverse vaginal microbial composition in the absence of symptomatic disease. The structures of the upper FRT (the endocervix, uterus, Fallopian tubes, and ovaries) have distinct, lower biomass microbiotas than the vagina; however, the existence of permanent microbiotas at these sites is disputed. During homeostasis, a balance exists between the FRT bacteria and the immune system that maintains immune quiescence. Alterations in the bacteria, immune system, or local environment may result in perturbances to the FRT microbiota, defined as dysbiosis. The inflammatory signature of a perturbed or “dysbiotic” FRT microbiota is characterized by elevated concentrations of pro-inflammatory cytokines in cervical and vaginal fluid. It appears that vaginal homeostasis can be disrupted by two different mechanisms: first, a shift toward increased bacterial diversity can trigger vaginal inflammation, and second, local immunity is altered in some manner, which disrupts the microbiota in response to an environmental change. FRT dysbiosis can have negative effects on reproductive health. This review will examine the increasing evidence for the involvement of the FRT microbiotas and inflammation in gynecologic conditions such as endometriosis, infertility, and endometrial and ovarian cancer; however, the precise mechanisms by which bacteria are involved in these conditions remains speculative at present. While only in their infancy, the use of antibiotics and probiotics to therapeutically alter the FRT microbiota is being studied and is discussed herein. Our current understanding of the intimate relationship between immunity and the FRT microbiota is in its early days, and more research is needed to deepen our mechanistic understanding of this relationship and to assess how our present knowledge can be harnessed to assist in diagnosis and treatment of gynecologic conditions.

Research update for the immune microenvironment of chronic endometritis

Chronic endometritis (CE) is a persistent and subtle local inflammatory disease characterized by abnormal plasma cell infiltration in the endometrial stroma.The incidence of chronic endometritis is as high as 15-57.5% in women suffering from infertility, implantation failure of in vitro fertilization (IVF) and unexplained recurrent abortion. Many studies both at home and abroad have shown that CE can reduce the receptivity of endometrium and affect embryo implantation. According to the existing reproductive immunity research, the abnormality of immune cell subsets in endometrium is an important factors leading to pregnancy failure. The immune microenvironment in endometrium consists of immune cells and immune molecules, and their influence on embryo implantation can not be ignored. This review paper discusses the controversy of pathogenesis, diagnosis and treatment of CE from the perspective of immune microenvironment by referring to related literature at home and abroad, and investigates the possible ways to improve the diagnosis and treatment of CE.

Does antibiotic therapy for chronic endometritis improve clinical outcomes of patients with recurrent implantation failure in subsequent IVF cycles? A systematic review and meta-analysis

PURPOSE

This study aims to assess whether antibiotic therapy for chronic endometritis (CE) could improve subsequent IVF outcomes in patients with recurrent implantation failure (RIF).

METHODS

Studies that explore CE treatment in patients with RIF were retrieved from PubMed, EMBASE, Wanfang, and Google Scholar up to Jan 31, 2022. All retrieved studies were selected according to the inclusion and exclusion criteria. The main outcome measures include implantation rate (IR), clinical pregnancy rate (CPR), ongoing pregnancy rate/live birth rate (OPR/LBR), and miscarriage rate (MR). Odds ratios (ORs) were analyzed for pregnancy outcomes with a 95% confidence interval (CI).

RESULTS

Nine articles were enrolled in this study. Patients receiving oral antibiotic administration (OAA) did not show any advantage over patients without CE with regard to IR, OPR/LBR, and MR, but they showed a higher CPR. Patients with cured CE after OAA therapy had significantly higher CPR, IR, and OPR/LBR compared with patients without CE. Patients with persistent CE after OAA therapy had significantly lower IR, CPR, and OPR/LBR compared with patients without CE. Patients with cured CE had significantly higher IR, CPR, and OPR/LBR compared with persistent CE patients.

CONCLUSIONS

Antibiotic treatment may improve the pregnancy outcomes of RIF patients in subsequent IVF cycles only if the condition of CE is confirmed cured in a control biopsy afterwards. Otherwise, no sufficient evidence has shown improvements in clinical outcomes in RIF patients with persistent CE.

Human papillomavirus prevalence in unexplained infertile women with chronic endometritis

Introduction: This study investigates unexplained infertile women with or without chronic endometritis (CE) and examines the prevalence of the human papillomavirus (HPV) in this population. Material and Method: This study was done with a cross-sectional and retrospective method. The prevalence of HPV infection and related cases in the participants were examined. In this study, 15 infertile women with CE and 64 infertile women without CE were and analyzed from four perspectives: negative HPV, low-risk HPV, probable high-risk HPV, and the presence of high-risk HPV. Results: The participants have mean age of 32.89 years ±3.95. High-risk HPV infection was detected in 3 (20%) and 11 (17%) of the patients with and without CE, respectively (p>0.05). The negative HPV (2 (13%) and 17 (26%)), low-risk HPV (3 (20%) and 20 (31%)), and probable high-risk HPV (7 (46%) and 16 (25%)) in infertile women with CE and infertile women had no significantly different prevalence (p>0.05). The two studied groups had no significantly different mean age, body mass index (BMI), and Infertility duration were not in (P=0.08, P=0.932, and P=0.283, respectively). Conclusion: HPV has no significantly different prevalence in unexplained infertile women with and without CE. It is recommended that this study be repeated with more unexplained infertile women with CE.

Endometrial Dysbiosis Is Related to Inflammatory Factors in Women with Repeated Implantation Failure: A Pilot Study

An abnormal endometrial microbiota has been suggested to impair the process of embryo implantation, thus leading to repeated implantation failure (RIF) in women undergoing in vitro fertilization (IVF). However, the molecular mechanisms linking uterine microbiota and IVF out-comes are still an open question. The aim of this cohort study was to outline the relationship between endometrial microbiota, inflammation and IVF outcomes. To this purpose, endometrial microbiota and selected components of the “cytokine network” were analyzed in women presenting RIF and divided between eubiosis and dysbiosis groups, according to the percentage of endometrial lactobacilli (≥90% or <90%, respectively). The Dysbiosis group presented significantly higher tissue concentrations of the inflammatory markers (IL-6, IL-1β, HIF-1α and COX-2) and significantly lower levels of the anti-inflammatory/well-being factors, IL-10 and IGF-1, with respect to women with eubiosis. Moreover, the Lactobacillus percentage was negatively related to the concentrations of the inflammatory molecules and positively related to IL-10/IGF-1. Interestingly, the number of IVF attempts was directly related to the levels of the inflammatory factors COX-2, IL-1β and HIF-1α in the eubiosis group. Overall, endometrial dysbiosis was demonstrated to be associated with inflammation-related endometrial changes affecting the process of embryo implantation, underlining the importance of assessing uterine microbiota in patients undergoing IVF.

Higher Chronic Endometritis Incidences within Infertile Polycystic Ovary Syndrome Clinical Cases

Background

Clinical cases of a polycystic ovarian syndrome (PCOS) have prolonged subclinical inflammation. Hysteroscopy has revealed worsened chronic endometritis (CE), particularly endometrial diffuse hyperemia, in PCOS patients. However, the possible relationships between PCOS and CE remain largely unexplored.

Methods

This retrospective-based investigation was conducted on 3336 infertile patients. The PCOS group consisted of 508 patients, while the non-POCS group consisted of 2828 individuals with normal ovarian function. Their clinical features and CE prevalence diagnosed with hysteroscopy were compared. The risk factors affecting the incidence of diffuse endometrial hyperemia were analyzed by binary logistic regression.

Results

The PCOS cohort and the non-PCOS cohort showed marked variations in age, body mass index (BMI), infertility (primary, secondary), basal hormone level (bFSH, bLH, bT, and PRL), anti-Müllerian hormone (AMH), and CA125 (P < 0.05). The prevalence of CE in PCOS women was 41.73% (212/508), markedly higher than the 28.50% in the non-PCOS cohort (806/2828). Variations within diffuse endometrial hyperemia prevalence were especially marked (P < 0.05). Furthermore, we found that the variables of BMI, bLH, bT, and AMH correlated with diffuse endometrial hyperemia.

Conclusions

CE prevalence was elevated in clinical cases of infertility associated with PCOS, and diffuse endometrial hyperemia was prevalent, as indicated by hysteroscopy. Furthermore, increased BMI, bLH, bT, and AMH levels all contribute to the risk of diffuse endometrial hyperemia.

Upstream stimulatory factor 2 (USF2) induced upregulation of triggering receptor expressed on myeloid cells 1 (TREM1) promotes endometritis by regulating toll-like receptor (TLR) 2/4-nuclear factor-kappaB (NF-κB) signaling pathway

Triggering receptor expressed on myeloid cells 1 (TREM1) participates in the development of endometritis. This study aims at identifying the effects and interaction of TREM1 and upstream stimulatory factor 2 (USF2) in endometritis by using a model of lipopolysaccharide (LPS)-induced human endometrial epithelial cells (HEnEpCs). ELISA was performed to determine the levels of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF-α) after LPS stimulation. TREM1 and USF2 expression was examined with RT-qPCR and Western blot. The JASPAR database was employed to predict the binding site between USF2 and TREM1, which was confirmed by luciferase reporter and chromatin immunoprecipitation assays. After TREM1 overexpression, IL-6, IL-1β, and TNF-α expression was detected by ELISA. Next, the binding of TREM1 to toll-like receptor (TLR) 2/4 was examined with co-immunoprecipitation. Then, proteins in TLR2/4-nuclear factor-kappaB (NF-κB) signaling in HEnEpCs under LPS condition were assessed by Western blot or immunofluorescence before and after TREM1 knockdown. Finally, TLR2 or TLR4 was silenced to explore whether intervene TLR2/4-NF-κB signaling pathway could rescue TREM1-overexpression-induced inflammation in LPS-induced HEnEpCs. Results revealed that upregulated TREM1 was observed in LPS-challenged HEnEpCs. Next, USF2 was found to have transcriptionally active TREM1 expression. Additionally, USF2 knockdown decreased the levels of IL-6, IL-1β, and TNF-α, whereas this effect was rescued after TREM1 overexpression. Besides, TREM1 could bind to TLR2/4 to regulate NF-κB signaling. Moreover, the intervention of TLR2/4-NF-κB signaling pathway rescued TREM1-overexpression-induced inflammation in LPS-stimulated HEnEpCs. Collectively, USF2 promotes endometritis by upregulating TREM1, thereby activating TLR2/4-NF-κB pathway.

A Novel Approach to Minimising Acute Equine Endometritis That May Help to Prevent the Development of the Chronic State

One of the most commonly encountered challenges in equine breeding is endometritis, which can be difficult to resolve and causes considerable economic losses to the industry. It is a multifactorial condition, developing as an exaggerated form of the normal physiological response to breeding. Seminal plasma proteins, spermatozoa, bacteria and debris initiate an inflammatory response; the resulting fluid and neutrophils are then cleared from the uterus along with the debris. However, in some mares, the response is prolonged or exaggerated, with much fluid formation and neutrophil infiltration leading to acute endometritis. A bacterial cause has been implicated, although in some cases no pathogenic organisms can be isolated on culture. It has been postulated that any one of a variety of bacteria could be involved, or dysbiosis of the uterine microbiome could be responsible. Repeated episodes of acute endometritis may lead to the pathology associated with chronic endometritis, with mucociliary dysfunction, vascular degeneration and plasma cell infiltration. This review examines the information that is currently available about equine endometritis, particularly about the role of the inseminate in the uterus, and its current treatment. There are some promising lines of research into treatment or prevention that may help to resolve the issue.

Nrf2/HO-1 pathway is involved the anti-inflammatory action of intrauterine infusion of platelet-rich plasma against lipopolysaccharides in endometritis

OBJECTIVE(S)

Endometritis is the inflammatory response of the uterine lining which is linked to infertility. Administration of platelet-rich plasma (PRP) represents a well-recommended strategy for the treatment of endometrium-associated infertility. In this study, we set to characterize the role and molecular mechanism of PRP intrauterine infusion in mice with endometritis.

METHODS

A mouse model of endometritis was established using lipopolysaccharide (LPS). Mouse endometrial epithelial cells were obtained in primary culture. PRP-treated cells were assayed for proliferative and apoptotic activities. Moreover, iNOS expression and chemokine and inflammatory factor contents in cells were assessed using RT-qPCR and ELISA. The mice were subjected to PRP intrauterine infusion. The expression of genes related to uterine development was analyzed by qPCR and the ki-67 content and caspase-3 activation in endometrial tissues were examined by immunohistochemistry. Finally, the Nrf2/HO-1 pathway activity in tissues was examined by Western blot.

RESULTS

LPS induced inflammatory cell recruitment and tissue damage in the endometrium of mice, along with significantly increased levels of inflammatory and chemokine factors. PRP significantly enhanced endometrial epithelial cell activity, decreased apoptosis, and reduced inflammatory factor secretion. In addition, PRP intrauterine infusion significantly increased the expression of genes related to uterine development, promoted tissue proliferation, decreased apoptosis, and diminished inflammatory response in endometrial tissues of mice. PRP intrauterine infusion significantly elevated Nrf2/HO-1 pathway activity in endometrial epithelial cells and tissues.

CONCLUSION

PRP intrauterine infusion significantly inhibited endometrial cell injury and alleviated the inflammatory response through activating the Nrf2/HO-1 pathway.

MUM-1 immunohistochemistry has high accuracy and reliability in the diagnosis of chronic endometritis: a multi-centre comparative study with CD-138 immunostaining

PURPOSE

The current gold standard for chronic endometritis (CE) diagnosis is immunohistochemistry (IHC) for CD-138. However, IHC for CD-138 is not exempt from diagnostic limitations. The aim of our study was to evaluate the reliability and accuracy of MUM-1 IHC, as compared with CD-138.

METHODS

This is a multi-centre, retrospective, observational study, which included three tertiary hysteroscopic centres in university teaching hospitals. One hundred ninety-three consecutive women of reproductive age were referred to our hysteroscopy services due to infertility, recurrent miscarriage, abnormal uterine bleeding, endometrial polyps or myomas. All women underwent hysteroscopy plus endometrial biopsy. Endometrial samples were analysed through histology, CD138 and MUM-1 IHC. The primary outcome was to evaluate the diagnostic accuracy of MUM-1 IHC for CE, as compared with CD-138 IHC.

RESULTS

Sensitivity and specificity of CD-138 and MUM-1 IHC were respectively 89.13%, 79.59% versus 93.48% and 85.03%. The overall diagnostic accuracy of MUM-1 and CD-138 IHC were similar (AUC = 0.893 vs AUC = 0.844). The intercorrelation coefficient for single measurements was high between the two techniques (ICC = 0.831, 0.761-0.881 95%CI). However, among CE positive women, MUM-1 allowed the identification of higher number of plasma cells/hpf than CD-138 (6.50 [SD 4.80] vs 5.05 [SD 3.37]; p = 0.017). Additionally, MUM-1 showed a higher inter-observer agreement as compared to CD-138.

CONCLUSION

IHC for MUM-1 and CD-138 showed a similar accuracy for detecting endometrial stromal plasma cells. Notably, MUM-1 showed higher reliability in the paired comparison of the individual samples than CD-138. Thus, MUM-1 may represent a novel, promising add-on technique for the diagnosis of CE.

The Endometrial Microbiome and Its Impact on Human Conception

Changes in the female genital tract microbiome are consistently correlated to gynecological and obstetrical pathologies, and tract dysbiosis can impact reproductive outcomes during fertility treatment. Nonetheless, a consensus regarding the physiological microbiome core inside the uterine cavity has not been reached due to a myriad of study limitations, such as sample size and experimental design variations, and the influence of endometrial bacterial communities on human reproduction remains debated. Understanding the healthy endometrial microbiota and how changes in its composition affect fertility would potentially allow personalized treatment through microbiome management during assisted reproductive therapies, ultimately leading to improvement of clinical outcomes. Here, we review current knowledge regarding the uterine microbiota and how it relates to human conception.

Hysteroscopic findings in chronic endometritis

Chronic endometritis (CE) is a subtle pathology. Despite being difficult to detect and probably underdiagnosed, it has great clinical relevance, representing as it does a reversible cause of infertility. Nowadays, histological examination with identification of endometrial stromal plasma cells is considered the gold standard for diagnosis. Diagnostic difficulties persist, however, as a result of the technical limitations of this method and the lack of standardized histological diagnostic criteria. Hysteroscopy has been proposed as an aid for CE diagnosis. The method works by detecting signs of inflammation (focal or diffuse hyperemia, stromal edema, presence of micropolyps and the typical strawberry aspect) on the endometrial surface. Yet, the jury is still out on how reliable this technique is. Hysteroscopy displays a high sensitivity (over 86% and up to 100%) and high negative predictive value (over 92% and up to 100%) in the diagnosis of CE, and it should probably be performed routinely in the assessment of patients with unexplained infertility, repeated implantation failure and repeated pregnancy loss; however, since values in the literature regarding specificity are conflicting, in cases of suspected CE, hysteroscopy may be combined with histological examination, which remains the gold standard to confirm CE. Considering that histopathological evaluation probably underdiagnoses CE, and that hysteroscopy tends to overdiagnose, further studies are needed to determine which technique (or combination of techniques) has greater value for patients.

Honokiol inhibits endoplasmic reticulum stress-associated lipopolysaccharide-induced inflammation and apoptosis in bovine endometrial epithelial cells

Honokiol (HKL) has been previously reported to exert anti-inflammatory effects in numerous diseases. However, the role of HKL in endometritis remains unclear. The present study aimed to explore and elucidate the role of HKL in a lipopolysaccharide (LPS)-induced in vitro model of endometritis. Bovine endometrial epithelial cells (bEECs) were pre-treated with HKL at doses of 1, 10 and 20 µM, followed by 1 µg/ml LPS. MTT assay was then used to detect cell viability. ELISA was utilized to measure the levels of the proinflammatory cytokines TNF-α, IL-1β and IL-6 in bEECs culture supernatants. Reverse transcription-quantitative PCR was further performed to examine the mRNA expression levels of these cytokines. Cell apoptosis was observed by TUNEL staining and the levels of Bcl-2, Bax, cleaved caspase 3 and cleaved caspase 9 were assayed by western blotting. Western blotting was also performed to detect the expression levels of endoplasmic reticulum (ER) stress-related proteins activating transcription factor 6, CCAAT-enhancer-binding protein homologous protein, inositol-requiring enzyme 1 and cleaved caspase 12 in bEECs. LPS treatment reduced cell viability and HKL treatment improved the viability of bEECs after LPS treatment. The LPS-induced inflammatory response and apoptosis in bEECs were also inhibited by HKL treatment. Additionally, the increased expression of ER stress-related proteins induced by LPS was reversed by HKL treatment. Following stimulation with the ER stress inducer tunicamycin, it was revealed that HKL attenuated ER stress and inhibited LPS-induced inflammatory response and apoptosis in bEECs. In summary, HKL inhibited ER stress associated with LPS-induced inflammation and apoptosis in bEECs, providing evidence that HKL can serve to be a novel agent for the treatment of endometritis.

Effectiveness comparison between Endometrial Receptivity Array, Immune Profiling and the combination in treating patients with multiple implantation failure

PROBLEM

The clinical value of endometrial receptivity array (ERA), endometrial immune profiling, or a combination of both for multiple implantation failure patients is unclear.

METHOD OF STUDY

One hundred and seventy-two women with a history of at least two or more consecutive implantation failures in IVF/ICSI treatment were included. According to patients' willingness, they were divided into four groups, 'no treatment', 'Immune Profiling', 'ERA' and 'ERA + Immune Profiling'. Endometrial biopsy was examined by ERA, immune profiling alone, or combination, and intention was adopted accordingly. Pregnancy outcomes were compared, and the association between ERA phases and endometrial immune profiling was also assessed.

RESULTS

The overall incidence rate of the displaced window of implantation (WOI) and endometrial immune dysregulations were 84.9% and 75.3%, respectively. Implantation rate was significantly higher in the 'ERA + Immune Profiling' group than the 'no treatment' group (P = 0.007). Clinical pregnancy rate was somewhat improved in the three treatment groups but with a borderline significance (P = 0.071). After controlling for other confounders, 'ERA + Immune Profiling' treatment was associated with a higher pregnancy rate [aOR (95%CI)  =  3.412 (1.387-8.395), P = 0.008]. There was no association between endometrial immune profiling and ERA phases.

CONCLUSIONS

Our findings highlight the high incidence of displaced WOI and endometrial immune dysregulation in multiple implantation failure patients. The combination of ERA and endometrial immune profiling is more likely to have clinical value than ERA or immune profiling alone. These data suggested the unsubstitutability of ERA and endometrial immune profiling on the treatment outcome for multiple implantation failure patients. This article is protected by copyright. All rights reserved.

The Diagnostic Criteria for Chronic Endometritis: A Survey of Pathologists

While acute endometritis is a reasonably well-defined entity of ascending infection and attendant active inflammation, chronic endometritis is less well defined. As part of a broad effort to define and refine the diagnostic criteria and management of the disease, we conducted a survey of pathologists to understand the variability in diagnostic criteria and implications of the diagnosis of nonspecific, nonobstetric chronic endometritis. Members of national and international professional pathology societies were surveyed utilizing anonymous electronic surveys designed to examine diagnostic criteria, etiological understanding and treatment implications of a pathologic diagnosis of nonspecific, nonobstetric chronic endometritis. There was substantial variability among pathologists in the diagnostic criteria used for making a diagnosis of nonspecific, nonobstetric chronic endometritis, with 28.5% of pathologists using the presence of a single plasma cell for making the diagnosis. There was additional variability in the use of special stains, reporting in the presence of coexisting lesions and the hormonal stage of the endometrium. There were no differences between generalists and specialists in the diagnostic criteria used, except the significantly greater likelihood of specialists making the diagnosis in gestational endometrium. The substantial variability in diagnostic criteria for nonspecific, nonobstetric chronic endometritis among pathologists, including among gynecologic pathologists, has the potential to confound the management of patients. Standardization of diagnostic criteria for chronic endometritis is essential to understand the implications of the diagnosis.

Identification of Uterine Microbiota in Infertile Women Receiving in vitro Fertilization With and Without Chronic Endometritis

In vitro fertilization (IVF) is an important assisted reproductive technology in treating infertility, whose failure rate is still high. Studies suggested that uterine microbiota are related to women’s reproductive diseases and persisting intrauterine bacterial infectious conditions, such as chronic endometritis (CE), impairing the pregnant processes. However, the relationship between uterine microbiota and IVF outcomes is still an open question. In the present study, 94 patients diagnosed with infertility were enrolled and were divided into CE (E group, n = 25) and non-CE (NE group, n = 69) groups depending on the hysteroscopy and immunohistochemistry. Subsequently, E (Ep, n = 8 and Enp, n = 17) and NE (NEp, n = 41 and NEnp, n = 28) groups were divided into pregnancy and non-pregnancy groups depending on the IVF outcomes, respectively. The uterine fluids were collected and microbial profiles were examined through the V4 region of 16S rRNA gene high-throughput sequencing. The results demonstrated that patients with CE had significantly lower clinical pregnancy rate compared with the non-CE patients (32 vs. 58.42%, p = 0.0014). The relative abundances of Proteobacteria and Acidobacteria were higher in the non-CE group, whereas high abundances of Actinobacteria and Fusobacteria were observed in the CE group at the phylum level. At the genus level, high relative abundances of Gardnerella were observed in the CE group and non-pregnancy groups, which significantly referred to the negative IVF outcome. In conclusion, CE may be a key factor for the negative outcome after IVF, of which the uterine microbiota plays a pivotal role, and the microbial diversity in uterine may serve as a biomarker to forecast the success of IVF outcome.

CircRNA circFADS2 is Downregulated in Endometritis and its Overexpression Promotes miR-643 Maturation in Human Endometrial Epithelial Cells to Suppress Cell Apoptosis

CircRNA circFADS2 suppresses LPS-induced inflammation, which plays a critical role in endometritis. Our preliminary sequencing analysis revealed a positive correlation between circFADS2 and miR-643, which also play protective roles in LPS-induced inflammation. Therefore, this study was performed to explore the involvement of circFADS2 in endometritis with a focus on its interaction with miR-643. RT-qPCR was performed to analyze the levels circFADS2, mature miR-643, and premature miR-643 in plasma samples from endometritis patients (n = 66) and healthy controls (n = 66). Pearson's correlation coefficient was applied to analyze correlations between these genes. The effect of circFADS2 on miR-643 maturation was analyzed by measuring miR-643 and premature miR-643 levels in circFADS2-overexpressed human endometrial epithelial cell line HEnEpCs. The role of circFADS2 and miR-643 in HEnEpC apoptosis under LPS treatment was analyzed by cell apoptosis assay. CircFADS2 was downregulated in endometritis and was positively correlated with mature miR-643, but not premature miR-643. CircFADS2 overexpression in HEnEpCs increased the level of mature miR-643 but not premature miR-643. Cell apoptosis analysis showed that circFADS2 and miR-643 overexpression protected HEnEpCs from LPS-induced cell apoptosis, and miR-643 inhibition reduced the effect of circFADS2 overexpression. CircFADS2 is downregulated in endometritis, and it overexpression promotes miR-643 maturation in HEnEpCs to suppress cell apoptosis.

Irisin protects female mice with LPS-induced endometritis through the AMPK/NF-κB pathway

OBJECTIVES

This research was designed to determine the role of irisin in lipopolysaccharide (LPS)-induced endometritis in female mice.

MATERIALS AND METHODS

Animals were randomly assigned into sham, sham + irisin, LPS, LPS + irisin (0.1, 1, 10 μg/kg), and LPS + irisin + compound C groups. Histological features and expression of AMPK, NF-κB, inflammatory mediators, and oxidative stress markers were compared among different groups.

RESULTS

The results showed that LPS resulted in obvious uterus damage, meanwhile, the inflammatory mediators (COX-2, iNOS, IL-1β, IL-6, and TNF-α), as well as NF-κB in the uterine tissue, were significantly increased and the level of adenosine monophosphate-activated protein kinase (AMPK) was reduced. Nevertheless, pretreatment with irisin reversed the phenomena caused by LPS. Interestingly, compound C (AMPK inhibitor) abolished irisin's effects on the uterus, which suggested that irisin's beneficial function was achieved through regulating the AMPK-NF-κB pathway. Moreover, LPS-induced alterations of oxidative factors (MnSOD, GSH, and MDA) were reversed significantly by pretreatment with irisin. This data indicated irisin's beneficial function was also related to antioxidation besides anti-inflammation.

CONCLUSION

Our study implies that irisin is a potential therapeutic agent for endometritis.

Hysteroscopic detection of chronic endometritis: Evaluating proposed hysteroscopic features suggestive of chronic endometritis

PURPOSE

To evaluate the proposed criteria in a large sample and in additional subgroups in order to test the validity of the hysteroscopic features widely-accepted as suggestive of CE.

METHOD(S)

All patients (n: 2675) underwent outpatient hysteroscopy, with the vaginoscopic approach technique. Hysteroscopic features such as, stromal oedema, diffuse or focal hyperaemia, "strawberry aspect", micropolyposis and endometrial polyps, are often indicate the presence of chronic endometritis. All hysteroscopic features, alone and in combination were applied in 7 (seven) different subgroups of the sample: total sample, women in reproductive age, women with infertility issues/IVF screening, women with history of recurrent miscarriages, menopausal women, and women with hysteroscopic indication of Abnormal Uterine Bleeding (AUB) in women of reproductive age and postmenopausal bleeding (PMB). From each case, endometrial samples were obtained and immunohistochemistry, identifying CD-138, was applied in order to diagnose CE.

RESULT(S)

A total of 2675 patients were included of which, 1444 women were found with at least one of the proposed hysteroscopic features mentioned above. Stromal oedema, focal or diffuse hyperaemia and "strawberry aspect" in combination with micropolyposis demonstrated higher rates of diagnostic accuracy in the detection of CE correlated to histologic confirmation. Micropolyposis, stromal oedema, focal or diffuse hyperaemia and "strawberry aspect" offer great diagnostic accuracy in the hysteroscopic detection of Chronic Endometritis, regardless reproductive status and/or clinical presentation. Endometrial polyps are not valid hysteroscopic features in cases of suspected CE.

CONCLUSION(S)

Diagnostic hysteroscopy can accurately diagnose cases of CE, based on stromal oedema, focal or diffuse hyperaemia and "strawberry aspect", in combination with micropolyposis. In subgroups of infertile women, higher diagnostic accuracy based on the hysteroscopic features mentioned, was more likely to be achieved. Whether endometrial polyps are suggestive of CE, when identified during office hysteroscopy, remains controversial.

Impact of oral antibiotic treatment for chronic endometritis on pregnancy outcomes in the following frozen-thawed embryo transfer cycles of infertile women: a cohort study of 640 embryo transfer cycles

OBJECTIVE

To investigate the therapeutic effect of antibiotic treatment on pregnancy outcomes in the following frozen-thawed embryo transfer cycles of infertile women.

DESIGN

Retrospective study.

SETTING

University assisted reproduction unit.

PATIENT(S)

A total of 640 women were included. Among them, the number of CD138+ cells per high-power field (CD138+/HPF) in the endometrium at the first evaluation was 0 in 88 women; 315 women had 1-4 CD138+/HPF and the remaining 237 had ≥5 CD138+/HPF. Finally, 26 of 237 women had persistent chronic endometritis (PCE) diagnosed.

INTERVENTION(S)

Hysteroscopy and endometrial biopsy were performed in the proliferative phase. After antibiotic treatment, endometrial biopsy samples were collected again.

MAIN OUTCOME MEASURE(S)

Live birth rate.

RESULT(S)

No significant difference in pregnancy outcomes was found between women with CD138+/HPF = 0 and those with CD138+/HPF 1-4. The cure rate was 89.0% in women with CD138+/HPF ≥5 after treatment. The implantation rate (51.6% vs. 32.3%, relative risk [RR] 2.23, 95% confidence interval [CI] 1.07-4.66), clinical pregnancy rate (65.7% vs. 42.3%, RR 2.62, 95% CI 1.17-5.86), live birth rate (52.1% vs. 30.7%, RR 2.45, 95% CI 1.04-5.76), and cumulative live birth rate (64.2% vs. 38.5%, RR 2.88, 95% CI 1.27-6.51) were all significantly higher in women with CD138+/HPF ≤4 than in women with PCE.

CONCLUSION(S)

CD138+/HPF ≤4 in the endometrium had no negative impact on pregnancy outcomes. Antibiotic treatment was an effective way to improve the reproductive outcomes of women with CD138+/HPF ≥5. PCE was associated with poorer pregnancy outcomes.

Chronic endometritis in women with suspected retained products of conception and their reproductive outcomes

OBJECTIVE

To determine whether women who underwent operative hysteroscopy for suspected retained products of conception (rPOC) have histopathologic evidence of chronic endometritis (CE).

DESIGN

Retrospective cohort.

SETTING

Academic center.

PATIENT(S)

One hundred and eleven women who underwent operative hysteroscopy for suspected rPOC between 2016 and 2018.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Evidence of CE on histopathology and subsequent reproductive outcomes.

RESULT(S)

One hundred and eleven women with retained products of conception were included in our study of which 26 (23.4%) were diagnosed with CE. Women without CE had a higher median gravidity (1 vs. 2, p = .021) and a higher median number of prior pregnancy losses (1 vs. 2 prior losses, p = .005) compared to those with CE. Subsequent pregnancy data were available for 63 women. There was no difference in the subsequent pregnancy rate (61.5 vs. 54%, p = .626) between those with and without CE. Once pregnant, miscarriage (37.5 vs. 25.9%, p = .524) and live birth rates (50 vs. 44.4%, p = .782) were similar between the groups. Women with CE received antibiotics 57.7% of the time, the most common of which was doxycycline (46.6%). Of the women with CE who received antibiotics (n = 10), 8 became pregnant, and 4 of whom went on to have a live birth.

CONCLUSION(S)

Nearly 1 in 4 women undergoing hysteroscopy for rPOC was incidentally diagnosed with CE. It is not clear whether CE is a causative agent for retained products or a response to the pregnancy loss. In this cohort, a diagnosis of CE did not negatively impact subsequent reproductive outcomes.

Pathological spectrum of endometrial biopsies in Saudi women with abnormal uterine bleeding: A retrospective study of 13-years

OBJECTIVES

To assess and age stratify the types and frequencies of endometrial pathologies in Saudi women with abnormal uterine bleeding (AUB) that underwent endometrial biopsies, at our hospital over a 13-year period.

METHODS

In a retrospective study, from 2006 to 2018, all endometrial biopsies from Saudi women with AUB, reported at the laboratory of King Saud University-Medical City, Riyadh, Saudi Arabia, were revisited and analyzed. The women were categorized into <40, between 40-55 and >55 years of age.

RESULTS

We analyzed 6458 biopsies. In <40 and 40-55 years' groups cyclical endometrium was most common followed by endometrial polyps and disordered proliferative endometrium. In the >55 years' group, atrophic endometrium was most common followed by endometrial polyps. The hyperplasias and malignancies together accounted for 7.2% of the study, majority in the >55 years' group. Simple hyperplasia without atypia was the most common (3.9%), followed by malignancies (1.9%), complex atypical hyperplasia (0.7%), complex hyperplasia without atypia (0.4%), and simple atypical hyperplasia (0.3%).

CONCLUSION

Awareness of the probable spectrum of endometrial histopathologies in the various ages is useful in guiding management. Endometrial biopsies are valuable in early detection of precancerous and cancerous endometrial lesions especially in women over 40 years.