Expression of gamma delta T cells and adhesion molecules in endometriotic tissue in patients with endometriosis and adenomyosis

Characterising the immune cell phenotype of ectopic adenomyosis lesions compared with eutopic endometrium: A systematic review

Inflammation is implicated in the symptomatology and the pathogenesis of adenomyosis. Injury at the endo-myometrial interface causes inflammation and may facilitate the invasion of endometrium into the myometrium, forming adenomyosis lesions. Their presence causes local inflammation, resulting in heavy menstrual bleeding, chronic pelvic pain, and subfertility. Immunological differences have been described in the eutopic endometrium from women with adenomyosis compared to healthy endometrium, and differences are also expected in the adenomyotic lesions compared with the correctly sited eutopic endometrium. This systematic review retrieved relevant articles from three databases with additional manual citation chaining from inception to 24th October 2022. Twenty-two eligible studies were selected in accordance with PRISMA guidelines. Risk of bias assessments were performed, and the findings presented thematically. Ectopic endometrial stroma contained an increased density of macrophages compared with eutopic endometrium in adenomyosis. This was associated with an increase in pro-inflammatory cytokines (IL-6, IL-8, ILβ-1, C-X-C Motif Chemokine Receptor 1(CXCR1), Monocyte Chemoattractant Protein-1 (MCP-1)), and an imbalance of anti-inflammatory cytokines (IL-22, IL-37). Cells in ectopic lesions also contained a higher levels of toll-like receptors and immune-mediated enzymes. However, the studies were heterogeneous, with inconsistent reporting of immune cell density within epithelial or stromal compartments, and inclusion of samples from different menstrual cycle phases in the same group for analysis. A detailed understanding of the immune cell phenotypes present in eutopic and ectopic endometrium in adenomyosis and associated dysregulated inflammatory processes will provide further insight into the pathogenesis, to enable identification of fertility-sparing treatments as an alternative to hysterectomy.

Increased NKG2A+CD8+ T-cell exhaustion in patients with adenomyosis

Immune dysregulation has long been proposed to be associated with adenomyosis, but the underlying mediators and mechanisms remain largely unexplored. Here, we used flow cytometry to investigate the alterations in immune cell subsets in adenomyotic uteri and analyze the phenotype and function of abnormal immune cells. We found that an increase in cluster of differentiation (CD)8⁺ T-cell number was the predominant alteration in ectopic lesions in patients with adenomyosis and was significantly associated with the severity of adenomyosis. Importantly, we identified an exhausted natural killer group protein 2A (NKG2A)⁺CD8⁺ T-cell subset that was associated with the severity of adenomyosis and found that the number of these cells was significantly increased in the eutopic endometrium and ectopic lesions. In addition, the increases in the expression of NKG2A ligand histocompatibility leucocyte antigen E and interleukin-15 in glandular epithelial cells in the adenomyotic microenvironment might contribute to CD8⁺ T-cell exhaustion by promoting NKG2A expression on CD8⁺ T cells or inhibiting the effector function of these cells. In conclusion, our data revealed a previously unrecognized role for NKG2A⁺CD8⁺ T-cell exhaustion in the pathogenesis of adenomyosis, indicating that therapeutic interventions designed to target and reinvigorate exhausted CD8⁺ T cells may be beneficial for patients with adenomyosis.

Bioinformatic analysis and machine learning to identify the diagnostic biomarkers and immune infiltration in adenomyosis

Background: Adenomyosis is a hormone-dependent benign gynecological disease characterized by the invasion of the endometrium into the myometrium. Women with adenomyosis can suffer from abnormal uterine bleeding, severe pelvic pain, and subfertility or infertility, which can interfere with their quality of life. However, effective diagnostic biomarkers for adenomyosis are currently lacking. The aim of this study is to explore the mechanism of adenomyosis by identifying biomarkers and potential therapeutic targets for adenomyosis and analyzing their correlation with immune infiltration in adenomyosis. Methods: Two datasets, GSE78851 and GSE68870, were downloaded and merged for differential expression analysis and functional enrichment analysis using R software. Weighted gene co-expression network analysis (WGCNA), the least absolute shrinkage and selection operator (LASSO), and support vector machine-recursive feature elimination (SVE-RFE) were combined to explore candidate genes. Quantitative reverse transcriptase PCR (qRT-PCR) was conducted to verify the biomarkers and receiver operating characteristic curve analysis was used to assess the diagnostic value of each biomarker. Single-sample Gene Set Enrichment Analysis (ssGSEA) and CIBERSORT were used to explore immune cell infiltration in adenomyosis and the correlation between diagnostic biomarkers and immune cells. Results: A total of 318 genes were differentially expressed. Through the analysis of differentially expressed genes and WGCNA, we obtained 189 adenomyosis-related genes. After utilizing the LASSO and SVM-RFE algorithms, four hub genes, namely, six-transmembrane epithelial antigen of the prostate-1 (STEAP1), translocase of outer mitochondrial membrane 20 (TOMM20), glycosyltransferase eight domain-containing 2 (GLT8D2), and NME/NM23 family member 5 (NME5) expressed in nucleoside-diphosphate kinase, were identified and verified by qRT-PCR. Immune infiltration analysis indicated that T helper 17 cells, CD56dim natural killer cells, monocytes, and memory B-cell may be associated with the occurrence of adenomyosis. There were significant correlations between the diagnostic biomarkers and immune cells. Conclusion: STEAP1, TOMM20, GLT8D2, and NME5 were identified as potential biomarkers and therapeutic targets for adenomyosis. Immune infiltration may contribute to the onset and progression of adenomyosis.

Intralipid infusion therapy as an adjunct treatment in women experiencing adenomyosis-related infertility

Background

Currently, there is some evidence that adenomyosis patients using gonadotropin-releasing hormone (GnRH) agonist long downregulation (LDR) prior to embryo transfer may improve in vitro fertilization (IVF) success rate, but not to the baseline expected success where there is no adenomyosis. Given the association between adenomyosis and an aberrant endometrial immune environment, many physicians also use prednisolone or Intralipid adjuvant treatments in combination with GnRH agonist therapy, despite neither being of proven benefit.

Objective

The purpose of this study was to investigate whether the addition of prednisolone or Intralipid immune therapy to GnRH agonist LDR improves fertility outcomes in patients with adenomyosis.

Methods

This is a retrospective cohort study of 116 consecutive adenomyosis patients who underwent their first transfer of a genetically screened euploid embryo between January 2019 and December 2020 at a private IVF clinic.

Results

There was no difference in maternal age, body mass index, number of embryo's transferred and gravidity or parity among the three treatment groups. Patients who received Intralipid had a poorer prognosis with a longer duration of infertility (4 years) and a higher number of previous embryo transfers (ETs, 5 previous ETs) compared to the comparison groups. Logistic regression analysis adjustment for all covariates revealed that LDR plus Intralipid therapy produced significantly higher live birth rates (LBRs; 60%) compared to LDR alone (40% LBR); yet, the addition of prednisolone to GnRH agonist LDR (30% LBR) provided no additional live birth benefit.

Conclusion

In this retrospective analysis, we showed Intralipid adjuvant treatment in combination with GnRH agonist therapy in adenomyosis patients undergoing IVF resulted in a LBR expected in women without adenomyosis using preimplantation genetic testing screened embryos. This benefit was not seen when using prednisolone as an adjuvant to GnRH agonist LDR. Future randomized clinical trials will be required to confirm the therapeutic benefit of Intralipid in combination with GnRH agonist therapy.

Uterine Adenomyosis: From Disease Pathogenesis to a New Medical Approach Using GnRH Antagonists

Uterine adenomyosis is a common chronic disorder frequently encountered in reproductive-age women, causing heavy menstrual bleeding, intense pelvic pain, and infertility. Despite its high prevalence, its etiopathogenesis is not yet fully understood, so there are currently no specific drugs to treat the disease. A number of dysregulated mechanisms are believed to contribute to adenomyosis development and symptoms, including sex steroid signaling, endometrial proliferation and invasiveness, and aberrant immune response. Abnormal sex steroid signaling, particularly hyperestrogenism and subsequent progesterone resistance, are known to play a pivotal role in its pathogenesis, which is why various antiestrogenic agents have been used to manage adenomyosis-related symptoms. Among them, gonadotropin-releasing hormone (GnRH) antagonists are swiftly gaining ground, with recent studies reporting efficient lesion regression and symptom alleviation. The aim of the present review is to compile available information on the pathogenesis of adenomyosis, explore the etiology and mechanisms of hyperestrogenism, and discuss the potential of antiestrogenic therapies for treating the disease and improving patient quality of life.

Immunological changes associated with adenomyosis: a systematic review

BACKGROUND

Adenomyosis is a benign gynecological disorder associated with subfertility, pelvic pain and abnormal uterine bleeding that have significant consequences for the health and quality of life of women. Histologically, it is defined as the presence of ectopic endometrial islets within the myometrium. Its pathogenesis has not yet been elucidated and several pieces of the puzzle are still missing. One process involved in the development of adenomyosis is the increased capacity of some endometrial cells to infiltrate the myometrium. Moreover, the local and systemic immune systems are associated with the onset of the disease and with maintaining it. Numerous observations have highlighted the activation of immune cells and the release of immune soluble factors in adenomyosis. The contribution of immunity occurs in conjunction with hormonal aberrations and activation of the epithelial to mesenchymal transition (EMT) pathway, which promotes migration of endometrial cells. Here, we review current knowledge on the immunological changes in adenomyosis, with the aim of further elucidation of the pathogenesis of this disease.

OBJECTIVE AND RATIONALE

The objective was to systematically review the literature regarding the role of the immune system in development of adenomyosis in the inner and the outer myometrium, in humans.

SEARCH METHODS

A systematic review of published human studies was performed in MEDLINE, EMBASE and Cochrane Library databases from 1970 to February 2019 using the combination of Medical Subject Headings (MeSH): Adenomyosis AND ('Immune System' OR 'Gonadal Steroid Hormones'), and free-text terms for the following search terms (and their variants): Adenomyosis AND (immunity OR immune OR macrophage OR 'natural killer cell' OR lymphocyte* OR leucocyte* OR HLA OR inflammation OR 'sex steroid' OR 'epithelial to mesenchymal transition' OR 'EMT'). Studies in which no comparison was made with control patients, without adenomyosis (systemic sample and/or eutopic endometrium), were excluded.

OUTCOMES

A total of 42 articles were included in our systematic review. Changes in innate and adaptive immune cell numbers were described in the eutopic and/or ectopic endometrium of women with adenomyosis compared to disease-free counterparts. They mostly described an increase in lymphocyte and macrophage cell populations in adenomyosis eutopic endometrium compared to controls. These observations underscore the immune contributions to the disease pathogenesis. Thirty-one cytokines and other markers involved in immune pathways were studied in the included articles. Pro-inflammatory cytokines (interleukin (IL) 6, IL1β, interferon (IFN) α, tumor necrosis factor α, IFNγ) as well as anti-inflammatory or regulatory mediators (IL10, transforming growth factor β…) were found to be elevated in the eutopic endometrium and/or in the ectopic endometrium of the myometrium in women with adenomyosis compared to controls. Moreover, in women affected by adenomyosis, immunity was reported to be directly or indirectly linked to sex steroid hormone aberrations (notably changes in progesterone receptor in eutopic and ectopic endometrium) in three studies and to EMT in four studies.

WIDER IMPLICATIONS

The available literature clearly depicts immunological changes that are associated with adenomyosis. Both systemic and local immune changes have been described in women affected by adenomyosis, with the coexistence of changes in inflammatory as well as anti-inflammatory signals. It is likely that these immune changes, through an EMT mechanism, stimulate the migration of endometrial cells into the myometrium that, together with an endocrine imbalance, promote this inflammatory process. In light of the considerable impact of adenomyosis on women's health, a better understanding of the role played by the immune system in adenomyosis is likely to yield new research opportunities to better understand its pathogenesis.

The endometrial immune environment of women with endometriosis

BACKGROUND

Endometriosis, a common oestrogen-dependent inflammatory disorder in women of reproductive age, is characterized by endometrial-like tissue outside its normal location in the uterus, which causes pelvic scarring, pain and infertility. While its pathogenesis is poorly understood, the immune system (systemically and locally in endometrium, pelvic endometriotic lesions and peritoneal fluid) is believed to play a central role in its aetiology, pathophysiology and associated morbidities of pain, infertility and poor pregnancy outcomes. However, immune cell populations within the endometrium of women with the disease have had incomplete phenotyping, thereby limiting insight into their roles in this disorder.

OBJECTIVE AND RATIONALE

The objective herein was to determine reproducible and consistent findings regarding specific immune cell populations and their abundance, steroid hormone responsiveness, functionality, activation states, and markers, locally and systemically in women with and without endometriosis.

SEARCH METHODS

A comprehensive English language PubMed, Medline and Google Scholar search was conducted with key search terms that included endometriosis, inflammation, human eutopic/ectopic endometrium, immune cells, immune population, immune system, macrophages, dendritic cells (DC), natural killer cells, mast cells, eosinophils, neutrophils, B cells and T cells.

OUTCOMES

In women with endometriosis compared to those without endometriosis, some endometrial immune cells display similar cycle-phase variation, whereas macrophages (Mø), immature DC and regulatory T cells behave differently. A pro-inflammatory Mø1 phenotype versus anti-inflammatory Mø2 phenotype predominates and natural killer cells display abnormal activity in endometrium of women with the disease. Conflicting data largely derive from small studies, variably defined hormonal milieu and different experimental approaches and technologies.

WIDER IMPLICATIONS

Phenotyping immune cell subtypes is essential to determine the role of the endometrial immune niche in pregnancy and endometrial homeostasis normally and in women with poor reproductive history and can facilitate development of innovative diagnostics and therapeutics for associated symptoms and compromised reproductive outcomes.

Endometrial biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women suffer from endometriosis, which is a costly, chronic disease that causes pelvic pain and subfertility. Laparoscopy is the gold standard diagnostic test for endometriosis, but it is expensive and carries surgical risks. Currently, there are no non-invasive tests available in clinical practice that accurately diagnose endometriosis. This is the first diagnostic test accuracy review of endometrial biomarkers for endometriosis that utilises Cochrane methodologies, providing an update on the rapidly expanding literature in this field.

OBJECTIVES

To determine the diagnostic accuracy of the endometrial biomarkers for pelvic endometriosis, using a surgical diagnosis as the reference standard. We evaluated the tests as replacement tests for diagnostic surgery and as triage tests to inform decisions to undertake surgery for endometriosis.

SEARCH METHODS

We did not restrict the searches to particular study designs, language or publication dates. To identify trials, we searched the following databases: CENTRAL (2015, July), MEDLINE (inception to May 2015), EMBASE (inception to May 2015), CINAHL (inception to April 2015), PsycINFO (inception to April 2015), Web of Science (inception to April 2015), LILACS (inception to April 2015), OAIster (inception to April 2015), TRIP (inception to April 2015) and ClinicalTrials.gov (inception to April 2015). We searched DARE and PubMed databases up to April 2015 to identify reviews and guidelines as sources of references to potentially relevant studies. We also performed searches for papers recently published and not yet indexed in the major databases. The search strategies incorporated words in the title, abstract, text words across the record and the medical subject headings (MeSH).

SELECTION CRITERIA

We considered published peer-reviewed, randomised controlled or cross-sectional studies of any size that included prospectively collected samples from any population of reproductive-aged women suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE).

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from each study and performed a quality assessment. For each endometrial diagnostic test, we classified the data as positive or negative for the surgical detection of endometriosis and calculated the estimates of sensitivity and specificity. We considered two or more tests evaluated in the same cohort as separate data sets. We used the bivariate model to obtain pooled estimates of sensitivity and specificity whenever sufficient data were available. The predetermined criteria for a clinically useful test to replace diagnostic surgery was one with a sensitivity of 94% and a specificity of 79%. The criteria for triage tests were set at sensitivity at or above 95% and specificity at or above 50%, which in case of negative results rules out the diagnosis (SnOUT test) or sensitivity at or above 50% with specificity at or above 95%, which in case of positive result rules in the diagnosis (SpIN test).

MAIN RESULTS

We included 54 studies involving 2729 participants, most of which were of poor methodological quality. The studies evaluated endometrial biomarkers either in specific phases of the menstrual cycle or outside of it, and the studies tested the biomarkers either in menstrual fluid, in whole endometrial tissue or in separate endometrial components. Twenty-seven studies evaluated the diagnostic performance of 22 endometrial biomarkers for endometriosis. These were angiogenesis and growth factors (PROK-1), cell-adhesion molecules (integrins α3β1, α4β1, β1 and α6), DNA-repair molecules (hTERT), endometrial and mitochondrial proteome, hormonal markers (CYP19, 17βHSD2, ER-α, ER-β), inflammatory markers (IL-1R2), myogenic markers (caldesmon, CALD-1), neural markers (PGP 9.5, VIP, CGRP, SP, NPY, NF) and tumour markers (CA-125). Most of these biomarkers were assessed in single studies, whilst only data for PGP 9.5 and CYP19 were available for meta-analysis. These two biomarkers demonstrated significant diversity for the diagnostic estimates between the studies; however, the data were too limited to reliably determine the sources of heterogeneity. The mean sensitivities and specificities of PGP 9.5 (7 studies, 361 women) were 0.96 (95% confidence interval (CI) 0.91 to 1.00) and 0.86 (95% CI 0.70 to 1.00), after excluding one outlier study, and for CYP19 (8 studies, 444 women), they were were 0.77 (95% CI 0.70 to 0.85) and 0.74 (95% CI 0.65 to 84), respectively. We could not statistically evaluate other biomarkers in a meaningful way. An additional 31 studies evaluated 77 biomarkers that showed no evidence of differences in expression levels between the groups of women with and without endometriosis.

AUTHORS' CONCLUSIONS

We could not statistically evaluate most of the biomarkers assessed in this review in a meaningful way. In view of the low quality of most of the included studies, the findings of this review should be interpreted with caution. Although PGP 9.5 met the criteria for a replacement test, it demonstrated considerable inter study heterogeneity in diagnostic estimates, the source of which could not be determined. Several endometrial biomarkers, such as endometrial proteome, 17βHSD2, IL-1R2, caldesmon and other neural markers (VIP, CGRP, SP, NPY and combination of VIP, PGP 9.5 and SP) showed promising evidence of diagnostic accuracy, but there was insufficient or poor quality evidence for any clinical recommendations. Laparoscopy remains the gold standard for the diagnosis of endometriosis, and using any non-invasive tests should only be undertaken in a research setting. We have also identified a number of biomarkers that demonstrated no diagnostic value for endometriosis. We recommend that researchers direct future studies towards biomarkers with high diagnostic potential in good quality diagnostic studies.

The Endometrium in Adenomyosis

Eutopic and ectopic endometria of women with adenomyosis show a series of metabolic and molecular abnormalities that increase angiogenesis and proliferation, decrease apoptosis, allow local production of estrogens, create progesterone resistance, and impair cytokine expression. These changes enhance the ability of the endometrium to infiltrate the junctional zone myometrium and the growth of ectopic tissue. In addition, in these subjects several immunological abnormalities have been observed, together with an increased production of ‘free radicals’ leading to excessive growth of endometrial stromal cells that may facilitate the establishment of adenomyosis. A limiting factor is that these studies have been performed on hysterectomy specimens representing final stages of the disease. This increased knowledge has created new therapeutic options, including the block of local aromatase production through the use of selective estrogen receptor modulators, estrogen-progestin combinations and gonadotropin-releasing hormone super agonists. Also promising are investigations into the mechanism of dysmenorrhea and abnormal uterine bleeding.

Endometrial stromal cells and immune cell populations within lymph nodes in a nonhuman primate model of endometriosis

Mounting evidence suggests that immunological responses may be altered in endometriosis. The baboon (Papio anubis) is generally considered the best model of endometriosis pathogenesis. The objective of the current study was to investigate for the first time immunological changes within uterine and peritoneal draining lymph nodes in a nonhuman primate baboon model of endometriosis. Paraffin-embedded femoral lymph nodes were obtained from 22 normally cycling female baboons (induced endometriosis n = 11; control n = 11). Immunohistochemical staining was performed with antibodies for endometrial stromal cells, T cells, immature and mature dendritic cells, and B cells. Lymph nodes were evaluated using an automated cellular imaging system. Endometrial stromal cells were significantly increased in lymph nodes from animals with induced endometriosis, compared to control animals (P = .033). In animals with induced endometriosis, some lymph node immune cell populations including T cells, dendritic cells and B cells were increased, suggesting an efficient early response or peritoneal drainage.

Different HLA-DR expression in endometriotic and adenomyotic lesions: correlation with transvaginal ultrasonography findings

OBJECTIVE

Human leukocyte antigen-DR (HLA-DR) has been implicated in eutopic and ectopic glandular epithelial cells in endometriosis. We investigated the expression of HLA-DR in endometriotic and adenomyotic tissues within the stromal and glandular cells. Moreover, we correlate the HLA-DR expression according the transvaginal ultrasonography findings.

METHODS

We studied operative and pathologic reports of 113 women who underwent laparoscopic or laparotomy treatment of endometrioma or adenomyosis. Tissues from 51 women with endometrioma and 62 women with adenomyosis were retrospectively evaluated. The distribution and intensity of the HLA-DR immunostaining was assessed using electron microscopy. Pathologic finding of the uterine junction zone and the size of endometrioma were evaluated with the laparoscopic results and the ultrasound findings.

RESULTS

In adenomyosis tissues, the percentage of HLA-DR cells expression was significantly higher in stromal cells (83.9%) compared to glandular cells (25.8%), (p<0.001). The number of HLA-DR-positive endometriotic glandular cells was significantly higher than the total glandular adenomyotic cells (p<0.005). HLA-DR-positive cells was significantly different between stromal (p<0.016) and glandular cells (p<0.044) in each side of endometrioma. Finally, HLA-DR-positive percentage cells were significantly more frequent in the secretory phase than the proliferative in stromal and glandular cells in both groups.

CONCLUSION

HLA-DR antigen expression in endometrium and adenomyotic tissues. However, HLA-DR expression is distributed preferentially in glandular epithelial cells in endometrioma and in the adenomyotic stroma. In both groups the HLA-DR expression was significantly higher in the secretory phase than the proliferative or glandular and stroma cells. Larger perspective studies are needed to establish the expression of HLA antigens in immune reactions which occur in adenomyosis and endometriosis.

Dendritic cell populations in the eutopic and ectopic endometrium of women with endometriosis

BACKGROUND

Immune alterations may be involved in the pathogenesis and progression of endometriosis. Dendritic cells (DCs) are potent antigen presenting cells that are highly involved in the initiation of the immune response. The aim of this study was to investigate DC populations in the eutopic and ectopic endometrium of women with endometriosis compared with controls.

METHODS

Hysterectomy samples were obtained from premenopausal women with (n = 33) and without (n = 28) endometriosis. In addition, paired peritoneal endometriotic lesions and uterine curettings were collected from 32 women with endometriosis. Specimen sections were stained immunohistochemically using antibodies for monoclonal mouse antibodies directed against human CD1a and CD83, which are specific for immature and mature DCs, respectively.

RESULTS

The mean density of endometrial CD1a+ DCs in the basal layer was significantly increased in women with endometriosis compared with controls during the proliferative phase only (P = 0.001). There was a highly significant decrease in the density of endometrial CD83+ DCs in women with endometriosis compared with controls in both layers of the endometrium across all phases of the menstrual cycle (P = 0.001). The density of CD1a+ DCs was significantly increased in peritoneal endometriotic lesions (P = 0.003) and in the surrounding peritoneum (P = 0.001) compared with paired uterine curettings and peritoneum distant from the lesion.

CONCLUSIONS

Both CD1a+ and CD83+ DC populations were altered in the eutopic and ectopic endometrium of women with endometriosis compared with controls. Alterations in these cells, which play a crucial role in the coordination of the immune response, may be involved in pain generation and the pathogenesis of endometriosis.

[Adenomyosis: update on a frequent but difficult diagnosis]

Adenomyosis is a frequent entity, with difficult diagnosis, often obtained by pathological analysis performed after hysterectomy. This condition can cause abnormal uterine bleeding and dysmenorrhea, frequent reasons for consultation and hysterectomy. The development of ultrasonographic and magnetic resonance imaging techniques allow preoperative diagnosis. They also permit the use of hysteroscopic techniques for conservative uterine surgery, and have brought diagnosis and management of this disease to the front of the scene. This article reviews the pathological description of the disease, its epidemiology, clinical presentations, useful and necessary explorations, etiopathogeny and available therapies.

IL-10-dependent down-regulation of MHC class II expression level on monocytes by peritoneal fluid from endometriosis patients

Endometriosis is a gynecologic disorder characterized by the ectopic growth of misplaced endometrial cells. Moreover, immunological abnormalities of cell-mediated and humoral immunity may be associated with the pathogenesis of endometriosis. The effects of peritoneal fluid (PF) from endometriosis patients on the expression levels of MHC class II and costimulatory molecules on the cell surfaces of monocytes were investigated. Compared to the PF of controls, the addition of 10% PF (n=10) from patients with endometriosis to culture medium significantly reduced the percentage of MHC class II-positive cells in cultures of a THP-1, monocytic cell line at 48 h. The effect of endometriosis patient PF (EPF) was dose-dependent, and similar effect was observed in peripheral blood monocytes. An inverse correlation was found between MHC class II expression level and IL-10 concentration in EPF (r=-0.518; p=0.019) and in the supernatant of peripheral blood monocyte cultured in EPF (r=-0.459; p=0.042) (n=20). The expression levels of costimulatory molecules (CD80 and CD86), but not of CD54 and B7-H1, were down-regulated by EPF. The mRNA level of HLA-DR was unaffected by EPF but protein level was reduced by EPF. Neutralizing IL-10 antibody abrogated MHC class II down-regulation on monocytes, which had been induced by EPF. However, in a functional assay, monocytes treated with EPF failed to stimulate T cell in mixed leukocyte reaction, although T cell proliferation was increased with EPF-treated monocytes and Staphylococcus enterotoxin B. These results suggest that MHC class II expression level on monocytes is down-regulated by EPF, but the cell stimulatory ability of monocytes does not coincide with MHC class II expression level.

Development of a nonsurgical diagnostic tool for endometriosis based on the detection of endometrial leukocyte subsets and serum CA-125 levels

OBJECTIVE

To determine whether the proportion of several leukocyte subsets is modulated in the endometrium of patients with endometriosis and, if yes, whether it can be used for diagnostic purposes.

DESIGN

Case-control study.

SETTING

Eight clinical institutions of the Montreal area.

PATIENT(S)

Women who underwent laparoscopy or laparotomy between 1997 and 2001, who had regular menstrual cycles and were not under hormone treatment for the previous 3 months were selected. This study included 368 women, 173 with surgically confirmed endometriosis and 195 controls with no surgical evidence of endometriosis.

INTERVENTIONS

MAIN OUTCOME MEASURE(S)

Cytometry analysis was used to measure the proportion of several leukocyte subsets among CD45(+) endometrial cells.

RESULT(S)

The proportion of CD3(+), CD16(+), CD3(-)HLADR(-), CD3(-)CD45RA(-), CD3(+)CD16(-), CD3(+)CD56(-), CD56(-)CD16(+), and CD16b(+) leukocytes was significantly altered in the endometrium of cases compared with controls. A multiple logistic regression model was adjusted with these endometrial leukocytes, serum CA-125 levels, risk factors, and confounders. The diagnostic performance of this predictive model was defined by a specificity of 95% and a sensitivity of 61%. Furthermore, the positive and negative predictive values were 91% and 75%, respectively.

CONCLUSION(S)

This predictive model represents a novel diagnostic tool to identify women with a high likelihood of suffering from endometriosis.

Adenomyosis

Adenomyosis is characterized as ectopic endometrial tissues within the myometrium in the uterus. The etiology and pathogenetic mechanism(s) responsible for adenomyosis are poorly understood. Definite diagnosis is made on hysterectomy specimens, although attempts are made at securing preoperative diagnosis by magnetic resonance imaging and myometrial biopsies. Definite treatment of symptomatic women is hysterectomy.

Aromatase P450 messenger RNA expression in eutopic endometrium is not a specific marker for pelvic endometriosis

OBJECTIVE

To determine whether expression of aromatase P450 mRNA in eutopic endometrium is predictive of the presence of pelvic endometriosis.

DESIGN

A prospective, multicenter, observational study.

SETTING

Four tertiary centers for reproductive medicine.

PATIENT(S)

Sixty subjects of reproductive age undergoing laparoscopy for subfertility exploration, pain assessment, or sterilization.

INTERVENTION(S)

Endometrial biopsy at time of laparoscopy.

MAIN OUTCOME MEASURE(S)

The expression of aromatase P450 mRNA in endometrial specimens was determined by single-tube reverse transcription-polymerase chain reaction (RT-PCR). Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA was amplified in parallel to exclude amplification failure.

RESULT(S)

The RT-PCR amplification was successful in 56 of the 60 biopsies (93%). Pelvic endometriosis was diagnosed in 34 patients (61%) and was strongly associated with aromatase P450 mRNA expression in eutopic endometrium. As a diagnostic marker for endometriosis, aromatase P450 mRNA expression yielded a sensitivity of 82%, a specificity of 59%, a positive predictive value of 76%, and a negative predictive value of 67%. If additional uterine pathology was taken in account, the sensitivity increased to 84%, the specificity to 72%, the positive predictive value to 87%, but the negative predictive value remained unchanged (67%).

CONCLUSION(S)

Although endometrial aromatase P450 gene expression is highly predictive of the presence of pelvic disease, the relative high incidence of false-negative results and lack of specificity is likely to impair clinical application.

Suppression of natural killer cell activity by splenocyte transplantation in a rat model of endometriosis

BACKGROUND

One immune characteristic of endometriosis is a decrease in natural killer (NK) cell activity. This study was performed to determine whether an abnormal immune reaction in an endometriosis animal model could be transferred to an animal of the same species.

METHODS

An endometriosis model was prepared using 8 week old female rats by grafting a small section of one uterine horn onto the mesentery, followed 4 weeks later by removal of the spleen and remaining uterine horn. Splenocytes, that had been depleted of macrophages were injected via the tail vein, and NK cell activity of splenocytes was determined 4 days later. The uterus was simultaneously investigated immunohistochemically for immune cells. There was a control group (untreated; group 1), a control-splenocyte injection group (group 2), an experimental endometriosis model group (group 3) and an endometriosis model splenocyte injection group (group 4).

RESULTS

Splenocyte NK cell activity was decreased in group 3 to 42.0% of that of group 1 and in group 4 to 38.9%. Immunohistologically, the number of NK cells in groups 3 and 4 markedly decreased to 62.0 and 55.1% of group 1 respectively.

CONCLUSION

It was demonstrated that abnormal immunity caused by allograft of immune cells could recur in an endometriosis rat model.

Enhanced T cells interactions with extracellular matrix proteins in infertile women with endometriosis

Essential features of endometriosis involve interactions with extracellular matrix (ECM). Recent data emphasize the important role of ECM proteins in the regulation of T cell function. The aim of this study was to determine activated T cell adhesion to ECM proteins in infertile women with endometriosis. Nine women with endometriosis diagnosed by laparoscopy according to the Revised American Fertility Society classification and ten normal healthy women with a previous successful pregnancy outcome were studied. We investigated phorbol acetate myristate (PMA) or phytohemaglutinin (PHA) activated peripheral blood T cell adhesion to the following proteins of ECM: collagen IV (C-IV), elastin (E) and fibronectin (Fn). In addition, CD4, CD8, CD29, CD45RO expression on peripheral CD3(+) T cells were studied using flow cytometry. We determine that PHA-activated T cell adhesion to C-IV and Fn are significantly higher in infertile women with endometriosis when compared to normal healthy women (P<0.05). No significant differences were noted in T cell's surface antigens expression between study groups. Our data suggest the existence of disturbed T cell-ECM interactions in infertile women with endometriosis. Further studies are needed to determine the role of these abnormalities in the pathogenesis of endometriosis.

Cytokine network of eutopic and ectopic endometrium in women with adenomyosis

PROBLEM

Recent studies showed the impairment of local cytokine balance in women with external endometriosis, but similar findings concerning direct production of cytokines by immunocompetent cells of women with adenomyosis are absent. In this context, investigation of the cytokine synthesis by mononuclear cells (MNCs) infiltrating eutopic and ectopic endometrium is of special interest.

METHOD OF STUDY

Concentration of interferon-gamma (IFNgamma), interferon-alpha (IFNalpha), tumour necrosis factor-alpha (TNFalpha), interleukin- 1beta (IL-1beta) and epidermal growth factor (EGF) in supernatants (SNs) of 24-hr cultures of MNCs obtained from eutopic and ectopic endometrium of women with adenomyosis was determined by enzyme-linked immunosorbent assay.

RESULTS

The levels of IFNgamma, IFNalpha, TNFalpha, IL-1beta and EGF in SNs of eutopic endometrial MNCs of women with adenomyosis were significantly increased and the content of IL-8 in SNs was reduced compared with that of the control figures. Ectopic MNCs of women with adenomyosis produced higher levels of IFNgamma, IFNalpha and TNFalpha than the MNCs of normal endometrium. The production of IL-1beta, IL-8 and EGF by ectopic endometrial MNCs was significantly reduced.

CONCLUSION

The results obtained indicate a significant role of local cytokine production impairment in the development of adenomyosis.

Immunohistochemical assessment of superoxide dismutase expression in the endometrium in endometriosis and adenomyosis

OBJECTIVE

To determine the expression of superoxide dismutase (SOD) in the endometrium during the menstrual cycle in endometriosis and adenomyosis.

DESIGN

Immunohistochemical identification of SOD in endometrial tissues using the monoclonal antibody.

SETTING

Department of obstetrics and gynecology in a university hospital.

PATIENT(S)

The subjects were divided into three groups: 36 patients with endometriosis, 38 patients with histologically proven adenomyosis, and 47 fertile control subjects.

INTERVENTION(S)

Endometrium was biopsied throughout the menstrual cycle.

MAIN OUTCOME MEASURE(S)

Semiquantitative immunostaining (evaluation nomogram) score for endometrial cells.

RESULT(S)

The analyses revealed phase-dependent changes in the expression of SODs in the glandular and surface epithelia during the menstrual cycle in fertile controls. Specifically, the expression of copper, zinc SOD was weakest in the early and midproliferative phases, then gradually increased, and was most marked in the early and midsecretory phases. The expression of manganese SOD reached a peak in the late secretory phase. The expression of both SODs in endometriosis and adenomyosis was persistently higher than the control levels throughout the menstrual cycle.

CONCLUSION(S)

The exaggerated expression of both SODs in the endometrium throughout the menstrual cycle suggests that superoxide plays a key role in infertility in endometriosis and adenomyosis.

Endometriosis: abnormal endometrium and dysfunctional immune response

This review highlights recent studies that illuminate the role of the immune system in endometriosis. The findings are discussed in the framework of a model which proposes that endometriosis reflects an immunological selection process. Endometrial cells, which are inherently resistant to apoptosis and immune-mediated elimination, acquire the capacity to utilize the products of an activated immune system to establish ectopic foci of disease. Cyclical inflammatory/immune cell stimulation that fails to eliminate ectopic endometrial implants results in progressive immunological derangement and associated pathophysiological changes which are characteristic of the disease.

Endothelial nitric oxide synthase in the endometrium during the menstrual cycle in patients with endometriosis and adenomyosis

OBJECTIVE

To determine the expression of endothelial nitric oxide synthase in the endometrium during the menstrual cycle in endometriosis and adenomyosis.

DESIGN

Immunohistochemical identification of endothelial nitric oxide in endometrial tissues using the monoclonal antibody.

SETTING

Department of obstetrics and gynecology in a university hospital.

PATIENT(S)

The subjects were divided into three groups: 35 patients with endometriosis, 33 patients with adenomyosis proven histologically, and 46 fertile controls.

MAIN OUTCOME MEASURE(S)

Semiquantitative immunostaining (evaluation nomogram) score in endometrial cells.

RESULT(S)

The analyses revealed phase-dependent changes in the expression of endothelial nitric oxide synthase in the surface and glandular epithelia during the menstrual cycle in the fertile controls. The expression was weakest in the early proliferative phase, gradually increased, was most marked in the midsecretory phase, and decreased thereafter. In contrast, stromal cells did not change throughout the cycle. Contrary to expectations, the expression of endothelial nitric oxide synthase in endometriosis and adenomyosis was persistently greater than the control levels throughout the menstrual cycle.

CONCLUSION(S)

This study has shown that endothelial nitric oxide synthase is changed in a phase-dependent manner during the menstrual cycle. The exaggerated expression of endothelial nitric oxide synthase in the endometrium throughout the cycle suggests some pathologic role in endometriosis and adenomyosis.

Endometrial leukocytes are altered numerically and functionally in women with implantation defects

PROBLEM

A significant cohort of women with autoimmune thyroid disease (ATD) also suffer from reduced fertility. The finding that neither exogenous hormones nor donor eggs correct the infertility suggests that the problem involves an inherent endometrial defect.

METHOD OF STUDY

Endometrial leukocyte populations in women with ATD were quantitated by immunohistochemistry. A semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) technique was used to examine the expression of transforming growth factor (TGF)-beta 1, interleukin (IL)-4, IL-10, and interferon (IFN)-gamma in the endometrial samples.

RESULTS

A significant increase in the endometrial T-cell population was observed in women with ATD compared to controls. The relative abundance of IL-4 and IL-10 was decreased in women with ATD compared to controls, whereas IFN-gamma was increased. No difference was noted in the abundance of TGF-beta 1. The source of cytokine production for IL-4, IL-10, and IFN-gamma was the endometrial leukocytes.

CONCLUSIONS

Both the leukocyte numbers and cytokine expression profile were altered significantly in a well-defined group of women with implantation defects.

Integrin adhesion molecules in the endometrial glandular epithelium in patients with endometriosis or adenomyosis

OBJECTIVE

To assess the role of beta 1-integrin and E-cadherin molecules in the eutopic glandular epithelium in patients with endometriosis or adenomyosis.

STUDY DESIGN

Twenty-four patients with endometriosis, and 22 patients with adenomyosis diagnosed histologically were selected as subjects. The controls consisted of 29 fertile women. Eutopic endometria were obtained by curettage or immediately after the operation. The samples were immunohistochemically examined for the expression of very late activation antigen-2 (VLA-2), VLA-3, VLA-4, VLA-5, VLA-6, and E-cadherin.

RESULTS

The expression of each VLA molecule and E-cadherin except VLA-4, VLA-5, and VLA-6 was significantly increased throughout the menstrual cycle in endometria in both the endometriosis and adenomyosis groups. In contrast, the expression of VLA-4 in the adenomyosis group was significantly reduced in the secretory phase.

CONCLUSION

Altered expression of beta 1-integrins and E-cadherin was observed throughout the menstrual cycle in patients with endometriosis and adenomyosis, suggesting the defective microenvironment of the endometrium.

Distribution of heat shock proteins in eutopic and ectopic endometrium in endometriosis and adenomyosis

OBJECTIVE

To evaluate the pathophysiologic role of heat shock proteins and to examine the effect of danazol on these proteins in patients with endometriosis and adenomyosis.

DESIGN

Immunohistochemical identification of human heat shock proteins 27, 60, and 70 in endometrial glandular cells identified using monoclonal antibodies.

SETTING

Department of obstetrics and gynecology in a university hospital.

PATIENT(S)

Subjects were 119 women with documented endometriosis or adenomyosis. The subjects were divided into three groups: fertile control (n = 38), with 14 in the proliferative phase and 24 in the secretory phase; endometriosis (n = 38); and adenomyosis (n = 43), including 33 who underwent hysterectomy and 10 treated with danazol.

MAIN OUTCOME MEASURE(S)

Staining of glandular cells by semiquantitative immunostaining (evaluation nomogram) score.

RESULT(S)

Significantly increased expression of heat shock protein 27 was noted in eutopic endometrium from patients with endometriosis and adenomyosis as compared with controls, regardless of the menstrual phase. The scores for heat shock protein 27 and heat shock protein 70 in the ectopic endometrium of patients with endometriosis were low compared with those in eutopic endometrium, whereas in adenomyosis, the scores were similar to those of eutopic endometrium. After treatment with danazol, the expression of heat shock proteins returned to control levels.

CONCLUSION(S)

We suggest that abnormally increased expression of heat shock proteins plays a role in the pathophysiology of endometriosis and adenomyosis.

Effect of danazol on the immunocompetent cells in the eutopic endometrium in patients with endometriosis: a multicenter cooperative study

OBJECTIVE

To assess the effects of danazol on immunocompetent cells, human leukocyte antigen (HLA) expression, and adhesion molecules in the eutopic endometrium of patients with endometriosis.

DESIGN

Antigens were localized immunohistochemically in the endometria, before treatment and during treatment (2 months later).

PARTICIPANTS

Ten patients with laparoscopically proven endometriosis who consented to participate in this study were treated with 400 mg/d of danazol for 4 months. Forty-two infertile patients without endometriosis or adenomyosis served as controls.

RESULTS

Immunohistochemical analysis revealed significantly increased expression of the T cell subsets, macrophages, adhesion molecules, and HLA antigens in eutopic endometrium in patients with endometriosis compared with the infertile group. Treatment with danazol reduced the number of cells in T cell subsets, adhesion molecules, or HLA antigen expression, especially of gamma delta T cells, to 39.5% of the pretreatment value in patients with endometriosis.

CONCLUSIONS

Danazol had an immunomodulatory effect on the autoimmune response in endometrium associated with endometriosis.