New endometrial immune cell-based score (EI-score) for the prediction of implantation success for patients undergoing IVF/ICSI

Analysis of cancer-specific survival in patients with metastatic colorectal cancer: A evidence-based medicine study

BACKGROUND

Metastatic colorectal cancer (mCRC) is a common malignancy whose treatment has been a clinical challenge. Cancer-specific survival (CSS) plays a crucial role in assessing patient prognosis and treatment outcomes. However, there is still limited research on the factors affecting CSS in mCRC patients and their correlation.

AIM

To predict CSS, we developed a new nomogram model and risk grading system to classify risk levels in patients with mCRC.

METHODS

Data were extracted from the United States Surveillance, Epidemiology, and End Results database from 2018 to 2023. All eligible patients were randomly divided into a training cohort and a validation cohort. The Cox proportional hazards model was used to investigate the independent risk factors for CSS. A new nomogram model was developed to predict CSS and was evaluated through internal and external validation.

RESULTS

A multivariate Cox proportional risk model was used to identify independent risk factors for CSS. Then, new CSS columns were developed based on these factors. The consistency index (C-index) of the histogram was 0.718 (95%CI: 0.712-0.725), and that of the validation cohort was 0.722 (95%CI: 0.711-0.732), indicating good discrimination ability and better performance than tumor-node-metastasis staging (C-index: 0.712-0.732). For the training set, 0.533, 95%CI: 0.525-0.540; for the verification set, 0.524, 95%CI: 0.513-0.535. The calibration map and clinical decision curve showed good agreement and good potential clinical validity. The risk grading system divided all patients into three groups, and the Kaplan-Meier curve showed good stratification and differentiation of CSS between different groups. The median CSS times in the low-risk, medium-risk, and high-risk groups were 36 months (95%CI: 34.987-37.013), 18 months (95%CI: 17.273-18.727), and 5 months (95%CI: 4.503-5.497), respectively.

CONCLUSION

Our study developed a new nomogram model to predict CSS in patients with synchronous mCRC. In addition, the risk-grading system helps to accurately assess patient prognosis and guide treatment.

Current Status of Ovarian and Endometrial Biomarkers in Predicting ART Outcomes

This review evaluates the role of ovarian and endometrial biomarkers in predicting outcomes in assisted reproductive technology (ART). It highlights established ovarian biomarkers such as the anti-Müllerian hormone (AMH) and follicle-stimulating hormone (FSH), alongside emerging ones like growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), connexin, and granulosa cell gene profiles. Additionally, the paper explores endometrial biomarkers such as ERA, BCL6, and immune markers, as well as the potential for genomic and proteomic technologies in customizing implantation. It concludes that while many of these biomarkers show promise, their clinical integration requires rigorous research and validation to confirm their safety and utility in ART.

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.

Exploring Natural Killer Cell Testing in Embryo Implantation and Reproductive Failure: An Overview of Techniques and Controversies

The blastocyst nidation is the most crucial stage to a successful pregnancy, as the white cells work to promote a favorable endometrial microenvironment for this process. Intriguingly, this implantation window lasts, on average, 6 days in most regular women, and its quality is affected by many pathological conditions. Since the grounds of reproductive failure in healthy couples are still uncharted, studies have widely suggested a potential hostile role of the immune system in the equilibrium of the maternal-fetal interface. In recent years, natural killer cells have been the highlight as they represent the greatest lymphocyte in the uterus and have immune surveillance through cytotoxicity during the implantation window. This review explored the main techniques used for natural killer (NK) cell testing in the implantation window over the last 13 years on the PubMed® database. Of 2167 published articles potentially relevant for the review, only thirty-three were about cell evaluation in healthy women, met the inclusion criteria, and had their methodology critically analyzed. Here, we bring a summary from the study group and sample collection to evidence comments about their findings and correlations. Meanwhile, we also summarize the current relationship between NK cells and endometrial receptivity with reproductive failure to help enhance the possibilities for future research. In conclusion, our overview points out that restricted and unstandardized methods support the controversy between the NK population and unsuccessful embryo implantation, which is an obstacle to studying why healthy eggs do not thrive and finding a solution for one of the most controversial topics in human reproduction.

The effectiveness and safety of intrauterine infusion of autologous regulatory T cells (Tregs) in patients with recurrent pregnancy loss and low levels of endometrial FoxP3+ cells: A retrospective cohort study

PROBLEM

Regulatory T cells (Tregs) are a specialized type of T cells that help maintain immune tolerance and homeostasis. The potential of Tregs cell-based therapies in treating diseases has been demonstrated in several clinical trials, which have shown promising outcomes and high safety in autoimmune diseases, transplant rejection, and graft-versus-host disease. However, their effectiveness and safety in improving endometrial receptivity and reducing pregnancy loss in human reproduction are unknown.

METHOD OF STUDY

The study used a retrospective design and included patients with recurrent pregnancy loss (RPL) and lower levels of endometrial FoxP3⁺ Tregs. Patients in the Tregs group (n = 33) received intrauterine Tregs infusion three times during the follicular phase, while the control group (n = 28) did not receive any intrauterine infusion.

RESULTS

The intrauterine infusion of autologous Tregs increased the levels of FoxP3⁺ Tregs and CD56⁺ NK cells. Patients in the Treg group had higher live birth rates and lower miscarriage rates, especially early miscarriage rates. However, the two groups had no differences in the implantation rate, clinical pregnancy rate, and percentage of preterm delivery.

CONCLUSIONS

The findings suggest that intrauterine Tregs infusion may be a potential therapeutic approach for RPL. Further research in larger clinical trials is needed to confirm these findings.

Endometrial proteomic profile of patients with repeated implantation failure

Introduction

Successful embryo implantation, is the initiating step of pregnancy, relies on not only the high quality of the embryo but also the synergistic development of a healthy endometrium. Characterization and identification of biomarkers for the receptive endometrium is an effective method for increasing the probability of successful embryo implantation.

Methods

Endometrial tissues from 22 women with a history of recurrent implantation failure (RIF) and 19 fertile controls were collected using biopsy catheters on 7-9 days after the peak of luteinizing hormone. Differentially expressed proteins (DEPs) were identified in six patients with RIF and six fertile controls using isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomics analysis.

Results

Two hundred and sixty-three DEPs, including proteins with multiple bioactivities, such as protein translation, mitochondrial function, oxidoreductase activity, fatty acid and amino acid metabolism, were identified from iTRAQ. Four potential biomarkers for receptive endometrium named tubulin polymerization-promoting protein family member 3 TPPP3, S100 Calcium Binding Protein A13 (S100A13), 17b-hydroxysteroid dehydrogenase 2 (HSD17B2), and alpha-2-glycoprotein 1, zinc binding (AZGP1) were further verified using ProteinSimple Wes and immunohistochemical staining in all included samples (n=22 for RIF and n=19 for controls). Of the four proteins, the protein levels of TPPP3 and HSD17B2 were significantly downregulated in the endometrium of patients with RIF.

Discussion

Poor endometrial receptivity is considered the main reason for the decrease in pregnancy success rates in patients suffering from RIF. iTRAQ techniques based on isotope markers can identify and quantify low abundance proteomics, and may be suitable for identifying differentially expressed proteins in RIF. This study provides novel evidence that TPPP3 and HSD17B2 may be effective targets for the diagnosis and treatment of non-receptive endometrium and RIF.

Immune profiling and RNA-seq uncover the cause of partial unexplained recurrent implantation failure

BACKGROUND

Detailed knowledge of the changes in endometrial immune cells during the window of implantation in unexplained recurrent implantation failure (RIF) patients, the functions performed by immune cells, and the interactions between them is largely lacking. This study aimed to classify RIF patients and explore the mechanism through endometrial immune profiling and RNA-seq analysis.

METHODS

This study enrolled a total of 172 patients, comprising 144 women with unexplained RIF and 28 fertile women. Endometrial samples were collected using endometrial scratching at the mid-luteal phase before in vitro fertilization treatment or pregnancy. Transcriptome sequencing and immunohistochemical staining of endometrial immune cells including natural killer (NK) cells, macrophages, T cells, and B cells were performed.

MAIN OUTCOME MEASURE(S)

Comparison of the percentage of endometrial immune cells and the RNA-seq information between RIF patients and fertile control patients.

RESULT(S)

The proportions of uterine CD56⁺ uNK cells, CD57⁺ NKT cells, CD68⁺ macrophages, and CD19⁺ B cells were significantly elevated in RIF patients. In addition, the number of positive CD68 glandular lumens was significantly higher in RIF patients than in the fertile group. In addition, based on this result, we classified RIF patients into three categories.

CONCLUSION(S)

Hyperactivation of endometrial immune cells may be associated with reduced endometrial tolerance and recurrent implantation failure, affecting pregnancy outcomes in RIF patients.

How do pre-pregnancy endometrial macrophages contribute to pregnancy?

Macrophages are professional phagocytes with a wide distribution in all tissues throughout the body. Macrophages play a crucial role in homeostasis and numerous physiological processes beyond innate and adaptive immunity, including cellular debris removal, metabolic regulation, tissue repair, and tissue remodeling. Uterine macrophages are a heterogeneous and highly plastic subset of immune cells regulated by the local microenvironment and, in addition to their anti-inflammatory and anti-infective functions, support the establishment and maintenance of pregnancy. Comprehensive reviews have summarized the role of decidual macrophages during pregnancy. However, the distribution of macrophages in the endometrium prior to pregnancy, their functional remodeling, and the knock-on effects on subsequent pregnancies have not been elucidated. In this review, we focus on 1) how the phenotypes of endometrial macrophages and their interactions with other endometrial cells indicate or contribute to the subsequent pregnancy, 2) the adaptive switching of endometrial macrophages during the initial establishment of pregnancy, 3) and the pregnancy complications and pregnancy-related disorders associated with endometrial macrophages.

Gradient Boosting Machine Learning Model for Defective Endometrial Receptivity Prediction by Macrophage-Endometrium Interaction Modules

Background

A receptive endometrium is a prerequisite for successful embryo implantation. Mounting evidence shows that nearly one-third of infertility and implantation failures are caused by defective endometrial receptivity. This study pooled 218 subjects from multiple datasets to investigate the association of the immune infiltration level with reproductive outcome. Additionally, macrophage-endometrium interaction modules were constructed to explore an accurate and cost-effective approach to endometrial receptivity assessment.

Methods

Immune-infiltration levels in 4 GEO datasets (n=218) were analyzed and validated through meta-analysis. Macrophage-endometrium interaction modules were selected based on the weighted gene co-expression network in GSE58144 and differentially expressed genes dominated by GSE19834 dataset. Xgboost, random forests, and regression algorithms were applied to predictive models. Subsequently, the efficacy of the models was compared and validated in the GSE165004 dataset. Forty clinical samples (RT-PCR and western blot) were performed for expression and model validation, and the results were compared to those of endometrial thickness in clinical pregnancy assessment.

Results

Altered levels of Mϕs infiltration were shown to critically influence embryo implantation. The three selected modules, manifested as macrophage-endometrium interactions, were enrichment in the immunoreactivity, decidualization, and signaling functions and pathways. Moreover, hub genes within the modules exerted significant reproductive prognostic effects. The xgboost algorithm showed the best performance among the machine learning models, with AUCs of 0.998 (95% CI 0.994-1) and 0.993 (95% CI 0.979-1) in GSE58144 and GSE165004 datasets, respectively. These results were significantly superior to those of the other two models (random forest and regression). Similarly, the model was significantly superior to ultrasonography (endometrial thickness) with a better cost-benefit ratio in the population.

Conclusion

Successful embryo implantation is associated with infiltration levels of Mϕs, manifested in genetic modules involved in macrophage-endometrium interactions. Therefore, utilizing the hub genes in these modules can provide a platform for establishing excellent machine learning models to predict reproductive outcomes in patients with defective endometrial receptivity.

Establishment of an Artificial Neural Network Model Using Immune-Infiltration Related Factors for Endometrial Receptivity Assessment

Background: A comprehensive clinical strategy for infertility involves treatment and, more importantly, post-treatment evaluation. As a component of assessment, endometrial receptivity does not have a validated tool. This study was anchored on immune factors, which are critical factors affecting embryonic implantation. We aimed at establishing novel approaches for assessing endometrial receptivity to guide clinical practice. Methods: Immune-infiltration levels in the GSE58144 dataset (n = 115) from GEO were analysed by digital deconvolution and validated by immunofluorescence (n = 23). Then, modules that were most associated with M1/M2 macrophages and their hub genes were selected by weighted gene co-expression network as well as univariate analyses and validated using the GSE5099 macrophage dataset and qPCR analysis (n = 19). Finally, the artificial neural network model was established from hub genes and its predictive efficacy validated using the GSE165004 dataset (n = 72). Results: Dysregulation of M1 to M2 macrophage ratio is an important factor contributing to defective endometrial receptivity. M1/M2 related gene modules were enriched in three biological processes in macrophages: antigen presentation, interleukin-1-mediated signalling pathway, and phagosome acidification. Their hub genes were significantly altered in patients and associated with ribosomal, lysosomal, and proteasomal pathways. The established model exhibited an excellent predictive value in both datasets, with an accuracy of 98.3% and an AUC of 0.975 (95% CI 0.945–1). Conclusions: M1/M2 polarization influences endometrial receptivity by regulating three gene modules, while the established ANN model can be used to effectively assess endometrial receptivity to inform pregnancy and individualized clinical management strategies.

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.

CD19 and intraglandular CD163-positivity as prognostic indicators of pregnancy outcome in CD138-negative women with a previous fresh-embryo-transfer failure

Many factors impede embryonic implantation, and excluding obvious known factors such as chronic endometritis, the immune status of the endometrium may be related to pregnancy. Although an abundantly large number of immune cells infiltrate the endometrium during the secretory phase, whether these immune cells can be used as a predictor of prognosis in ART has not yet been clarified. In the present study we therefore retrospectively analyzed 97 CD138-negative women with a previous fresh-embryo-transfer failure. We assessed the expression of CD56+ uNK cells, CD16+ NK cells, CD57+ NK cells, CD68+ pan-macrophages, CD163+ M2 macrophages, CD4+T cells, CD8+T cells, FOXP3+ regulatory T cells, and CD19+ B cells in the endometrium by IHC to evaluate mid-luteal endometrial immune cells as prognostic indicators of pregnancy outcome in the next frozen-embryo-transfer cycle. CD19-positive cells and the intraglandular CD163-positivity rate increased significantly in the clinically non-pregnant group (0.47 % vs. 0.20 %, P =  0.021; 61 % vs. 30 %, P =  0.017). The ratios of CD4/CD8 were also higher in the non-pregnant group (1.96 vs. 1.45, P =  0.005).The area under the ROC curve of CD19 cell number alone, the intraglandular CD163-positivity alone, and CD19 number combined with the intraglandular CD163-positivity were 0.692 (95 % CI, 0.55-0.834), 0.661 (95 % CI, 0.514-0.809), and 0.748 (95 % CI, 0.614-0.882), respectively. The optimal cut-off value of CD19 was 0.464 %, and the clinical pregnancy rate and live-birth rate diminished significantly when the CD19 level was above this cut-off value. Our study suggests that CD19-positive cells and intraglandular CD163-positivity can be used as prognostic indicators of pregnancy outcome in CD138-negative patients who experienced first-fresh-embryo transfer failure.

Global transcriptomic changes occur in uterine fluid-derived extracellular vesicles during the endometrial window for embryo implantation

STUDY QUESTION

Are uterine fluid-derived extracellular vesicles (UF-EVs) a 'liquid biopsy' reservoir of biomarkers for real-time monitoring of endometrial status?

SUMMARY ANSWER

The transcriptomic cargo of UF-EVs reflects the RNA profile of the endometrial tissue as well as changes between the non-receptive and the receptive phase, possibly supporting its use for a novel endometrial receptivity test.

WHAT IS KNOWN ALREADY

EVs have been previously isolated from uterine fluid, where they likely contribute to the embryo-endometrium crosstalk during implantation. Based on a meta-analysis of studies on endometrial tissue implantation-associated genes and the human exosomes database, 28 of the 57 transcripts considered as receptivity markers refer to proteins present in human exosomes. However, the specific transcriptomic content of receptive phase UF-EVs has yet to be defined.

STUDY DESIGN, SIZE, DURATION

Two experimental series were set up. First, we simultaneously sequenced RNA species derived from paired UF-EVs and endometrial tissue samples collected from physiologically cycling women. Second, we analyzed RNA species of UF-EVs collected during the non-receptive (LH + 2) and receptive (LH + 7) phase of proven fertile women and from the receptive (LH + 7) phase of a population of women undergoing ART and transfer of euploid blastocysts.

PARTICIPANTS/MATERIALS, SETTING, METHODS

For paired UF-endometrial tissue sampling, endometrial tissue biopsies were obtained with the use of a Pipelle immediately after UF collection performed by lavage of the endometrial cavity. Overall, n = 87 UF samples were collected and fresh-processed for EV isolation and total RNA extraction, while western blotting was used to confirm the expression of EV protein markers of the isolated vesicles. Physical characterization of UF-EVs was performed by Nanoparticle Tracking Analysis. To define the transcriptomic cargo of UF-EV samples, RNA-seq libraries were successfully prepared from n = 83 UF-EVs samples and analyzed by RNA-seq analysis. Differential gene expression (DGE) analysis was used to compare RNA-seq results between different groups of samples. Functional enrichment analysis was performed by gene set enrichment analysis with g:Profiler. Pre-ranked gene set enrichment analysis (GSEA) with WebGestalt was used to compare RNA-seq results with the gene-set evaluated in a commercially available endometrial receptivity array.

MAIN RESULTS AND THE ROLE OF CHANCE

A highly significant correlation was found between transcriptional profiles of endometrial biopsies and pairwise UF-EV samples (Pearson's r = 0.70 P < 0.0001; Spearman's ρ = 0.65 P < 0.0001). In UF-EVs from fertile controls, 942 gene transcripts were more abundant and 1305 transcripts less abundant in the LH + 7 receptive versus the LH + 2 non-receptive phase. GSEA performed to evaluate concordance in transcriptional profile between the n = 238 genes included in the commercially available endometrial receptivity array and the LH + 7 versus LH + 2 UF-EV comparison demonstrated an extremely significant and consistent enrichment, with a normalized enrichment score (NES)=9.38 (P < 0.001) for transcripts up-regulated in LH + 7 in the commercial array and enriched in LH + 7 UF-EVs, and a NES = -5.40 (P < 0.001) for transcripts down-regulated in LH + 7 in the commercial array and depleted in LH + 7 UF-EVs. When analyzing LH + 7 UF-EVs of patients with successful versus failed implantation after transfer of one euploid blastocyst in the following cycle, we found 97 genes whose transcript levels were increased and 64 genes whose transcript levels were decreased in the group of women who achieved a pregnancy. GSEA performed to evaluate concordance in transcriptional profile between the commercially available endometrial receptivity array genes and the comparison of LH + 7 UF-EVs of women with successful versus failed implantation, demonstrated a significant enrichment with a NES = 2.14 (P = 0.001) for transcripts up-regulated in the commercial array in the receptive phase and enriched in UF-EVs of women who conceived, and a not significant NES = -1.18 (P = 0.3) for transcripts down-regulated in the commercial array and depleted in UF-EVs. In terms of physical features, UF-EVs showed a homogeneity among the different groups analyzed except for a slight but significant difference in EV size, being smaller in women with a successful implantation compared to patients who failed to conceive after euploid blastocyst transfer (mean diameter ± SD 205.5± 22.97 nm vs 221.5 ± 20.57 nm, respectively, P = 0.014).

LARGE SCALE DATA

Transcriptomic data were deposited in NCBI Gene Expression Omnibus (GEO) and can be retrieved using GEO series accession number: GSE158958.

LIMITATIONS, REASONS FOR CAUTION

Separation of RNA species associated with EV membranes might have been incomplete, and membrane-bound RNA species-rather than the internal RNA content of EVs-might have contributed to our RNA-seq results. Also, we cannot definitely distinguish the relative contribution of exosomes, microvesicles and apoptotic bodies to our findings. When considering patients undergoing ART, we did not collect UFs in the same cycle of the euploid embryo transfer but in the one immediately preceding. We considered this approach as the most appropriate in relation to the novel, explorative nature of our study. Based on our results, a validation of UF-EV RNA-seq analyses in the same cycle in which embryo transfer is performed could be hypothesized.

WIDER IMPLICATIONS OF THE FINDINGS

On the largest sample size of human EVs ever analyzed with RNA-seq, this study establishes a gene signature to use for less-invasive endometrial receptivity tests. This report is indeed the first to show that the transcriptome of UF-EVs correlates with the endometrial tissue transcriptome, that RNA signatures in UF-EVs change with endometrial status, and that UF-EVs could serve as a reservoir for potential less-invasive collection of receptivity markers. This article thus represents a step forward in the design of less-invasive approaches for real-time monitoring of endometrial status, necessary for advancing the field of reproductive medicine.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by a competitive grant from European Society of Human Reproduction and Embryology (ESHRE Research Grant 2016-1). The authors have no financial or non-financial competing interests to disclose.

TRIAL REGISTRATION NUMBER

NA.