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

Towards a Better Understanding of Endometriosis-Related Infertility: A Review on How Endometriosis Affects Endometrial Receptivity

Endometriosis is the most common cause of infertility. Endometrial receptivity has been suggested to contribute to infertility and poor reproductive outcomes in affected women. Even though experimental and clinical data suggest that the endometrium differs in women with endometriosis, the pathogenesis of impaired endometrial receptivity remains incomplete. Therefore, this review summarizes the potential mechanisms that affect endometrial function and contribute to implantation failure. Contemporary data regarding hormone imbalance, inflammation, and immunoregulatory dysfunction will be reviewed here. In addition, genetic, epigenetic, glycosylation, metabolism and microRNA in endometriosis-related infertility/subfertility will be summarized. We provide a brief discussion and perspectives on their future clinical implications in the diagnosis and therapy to improve endometrial function in affected women.

Seven Hormonal Biomarkers for Diagnosing Endometriosis: Meta-Analysis and Adjusted Indirect Comparison of Diagnostic Test Accuracy

OBJECTIVE

To compare the diagnostic accuracy of different hormonal biomarkers and to find the most effective hormonal biomarker for the diagnosis of endometriosis.

DATA SOURCES

We conducted a systematic search using PubMed, EMBASE, Cochrane Library, and China Biomedical Literature to identify relevant studies from the first day of databases to August 2018.

METHODS OF STUDY SELECTION

Two independent reviewers screened for study eligibility and extracted data. Random controlled trials, cross-sectional studies, case-control studies, and cohort studies evaluating the diagnostic accuracy of hormonal markers for endometriosis were included.

TABULATION, INTEGRATION, AND RESULTS

We included 17 studies that involved 1279 participants and evaluated 7 hormonal biomarkers. The pooled sensitivity and specificity in endometriosis were .79 (.71, .86) and .89 (.82, .94) for aromatase, .30 (.18, .46) and .80 (.65, .90) for human chorionic gonadotropin/luteinizing hormone receptor, .75 (.66, .83) and .47 (.34, .60) for estrogen receptor (ER)-α, .65 (.56, .74) and .68 (.55, .80) for ER-β, .45 (.38-.52) and .92 (.85-.97) for serum prolactin, .69 (.51, .83) and .30 (.16, .49) for estrogen sulfotransferase, and .73 (.60-.84) and .48 (.33-.63) for 17β-hydroxysteroid dehydrogenase type 2 (17βHSD2). Compared with human chorionic gonadotropin/luteinizing hormone receptor, ER-α, ER-β, estrogen sulfotransferase, and 17βHSD2, aromatase had a higher sensitivity, specificity, positive likelihood ratio, and diagnostic odds ratio. The specificities of aromatase and serum prolactin were comparable, but the sensitivity, positive likelihood ratio, and positive likelihood ratio of serum prolactin were much lower than that of aromatase.

CONCLUSION

Aromatase may be an excellent diagnostic test for endometriosis. However, because of the moderate quality of the included studies and the limited sample size, this result requires more research to validate. (PROSPERO registration number: PROSPERO 2018 CRD42018105126.).

Hormonal biomarkers for the noninvasive diagnosis of endometriosis: A protocol for a network meta-analysis of diagnostic test accuracy

BACKGROUND

Endometriosis is a major cause of disability and compromised the quality of life in women and teenage girls. The gold standard for diagnosis of endometriosis is laparoscopy with histology of excised endometriosis lesions. However, women can suffer for 8 to 12 years before obtaining a correct diagnosis. Several biomarkers showed good diagnostic value for endometriosis, but no studies directly or indirectly compare the diagnostic value of different biomarkers. We perform this network meta-analysis (NMA) to assess the diagnostic accuracy of hormonal biomarkers, and to find a most effective hormonal biomarker for the diagnosis of endometriosis.

METHODS

A systematic search will be performed using PubMed, EMBASE, Cochrane Library and Chinese Biomedicine Literature to identify relevant studies from inception to August 2018. We will include random controlled trials, cross-sectional studies, case-control studies, and cohort studies that evaluated the diagnostic accuracy of hormonal markers for endometriosis. The Quality Assessment of Diagnostic Accuracy Studies 2 quality assessment tool will be used to assess the risk of bias in each study. Standard pairwise meta-analysis and NMA will be performed using STATA V.12.0, MetaDiSc 1.40 and R 3.4.1 software to compare the diagnostic efficacy of different hormonal biomarkers.

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSION

This study will summarize the direct and indirect evidence to determine the diagnostic accuracy of the hormonal biomarkers for endometriosis and attempt to find a most effective biomarker for the diagnosis of endometriosis.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required as this study is a meta-analysis based on published studies.

PROSPERO REGISTRATION NUMBER

CRD42018105126.

Intracrine Regulation of Estrogen and Other Sex Steroid Levels in Endometrium and Non-gynecological Tissues; Pathology, Physiology, and Drug Discovery

Our understanding of the intracrine (or local) regulation of estrogen and other steroid synthesis and degradation expanded in the last decades, also thanks to recent technological advances in chromatography mass-spectrometry. Estrogen responsive tissues and organs are not passive receivers of the pool of steroids present in the blood but they can actively modify the intra-tissue steroid concentrations. This allows fine-tuning the exposure of responsive tissues and organs to estrogens and other steroids in order to best respond to the physiological needs of each specific organ. Deviations in such intracrine control can lead to unbalanced steroid hormone exposure and disturbances. Through a systematic bibliographic search on the expression of the intracrine enzymes in various tissues, this review gives an up-to-date view of the intracrine estrogen metabolisms, and to a lesser extent that of progestogens and androgens, in the lower female genital tract, including the physiological control of endometrial functions, receptivity, menopausal status and related pathological conditions. An overview of the intracrine regulation in extra gynecological tissues such as the lungs, gastrointestinal tract, brain, colon and bone is given. Current therapeutic approaches aimed at interfering with these metabolisms and future perspectives are discussed.

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.

Surface plasmon resonance imaging biosensors for aromatase based on a potent inhibitor and a specific antibody: Sensor development and application for biological material

Aromatase (ARO) is an enzyme with potential diagnostic significance. Aberrant expression of aromatase in tissues is associated with a number of pathological conditions, including tumor of the breast, ovary, testes, liver, adrenal cortex and uterus, as well as endometriosis.

Two methods for the highly selective determination of ARO concentration in human tissues by using of two different biosensors co-operating with the surface plasmon resonance imaging technique (SPRI) have been developed. One of the developed biosensors contains immobilised rabbit polyclonal antibody specific for aromatase (Y-ARO), while the other contains immobilized ARO inhibitor-exemestane (E-ARO). Both biosensors specifically bound ARO from analyzed samples. The analytically useful dynamic response range of both biosensors is between 0.3 and 5.0 ng mL−1. The detection limit (3S.D.) of both biosensors is 90 pg mL−1. Standard deviation of both biosensors is 1%. Recoveries of ARO spikes are between 97 and 108% for both biosensors under model conditions and for real samples. Albumin and alkaline phosphatase are tolerated for both biosensors up to 10,000 fold excess.

Biomarkers of endometriosis

BACKGROUND

Diagnosis of endometriosis is surgical through laparoscopy, which is invasive, costly and associated with potential complications.

OBJECTIVES

A non-invasive test for diagnosis of endometriosis will focus the use of laparoscopy on women who are highly suspected of having endometriosis. This review includes studies about different biomarkers for endometriosis and their potential for the non-surgical diagnosis of this disease.

METHODS

This review covers studies that investigated different biomarkers in blood or endometrium. Studies that identified definite cutoff points and evaluated the diagnostic performance of the biomarker as a blood test for endometriosis are focused on.

RESULTS/CONCLUSIONS

Some of the markers investigated showed a good specificity, none of them showed a high sensitivity. More multi-center studies involving larger numbers of patients are required to identify the most useful biomarker.

The emerging use of aromatase inhibitors for endometriosis treatment

Endometriosis is defined as the growth of endometrial tissue outside of the uterine cavity. The disease occurs primarily in women of reproductive age but recurrent endometriosis is also detected in post-menopausal women. Regardless of age, endometriosis is associated with pain and reduces the quality of life for millions of women world-wide. Conventional therapies focus on reducing systemic levels of estrogen which results in cessation of endometriotic implant growth and pain symptoms associated with the disease. However, these treatments are not effective in all women and are not without side effects. Based upon the discovery that endometriotic tissue over-expresses aromatase, an enzyme critical for estrogen production, emphasis has been placed upon the use of aromatase inhibitors for the treatment of endometriosis and its associated symptoms. This article will review the rationale behind the use of aromatase inhibitors in treating endometriosis and summarize those studies which have evaluated the use of aromatase inhibitors in the treatment of endometriosis and its associated symptoms.

Endometrial aromatase mRNA as a possible screening tool for advanced endometriosis and adenomyosis

Endometriosis (ENDs) and adenomyosis (ADNs) are estrogen-dependent diseases. The aim of this study was to determine the clinical usefulness of examining endometrial biopsy specimens for aromatase cytochrome P450 (CYP19) as a diagnostic importance for endometriosis and adenomyosis. In general, the RT-PCR analyses of 101 samples revealed increased aromatase mRNA expression in eutopic endometrium in women with endometriosis and adenomyosis compared to healthy controls (p = 0.0002). The highest number of positive cases (93.3%) of CYP19 mRNA expression was detected in women with advanced disease stages. Concrete expression of CYP19 mRNA level in controls was 0.68 compared to patients with ADNs (1.21), ENDsL stage I-II (1.15) and ENDsA stage III-IV (1.65) (p < 0.0001), respectively. The possible influence of increased body mass index on aromatase expression in each group showed in controls an insignificant slight increase of aromatase expression, contrary to cases where this trend was the opposite. The results point to the higher (2.45-fold) difference in aromatase expression in patients with endometriosis stage III-IV compared to controls and provide direct evidence that screening for eutopic endometrial aromatase expression in combination with clinical data could be of discriminative value in the prediction of estrogen-dependent diseases, independent from body mass index.

In situ estrogen metabolism in proliferative endometria from untreated women with polycystic ovarian syndrome with and without endometrial hyperplasia

The aim of the present investigation was to study whether the endocrinological status of women bearing polycystic ovarian syndrome (PCOS) affects the endometrial in situ steroid metabolism. For this purpose, we evaluated the mRNA levels (RT-PCR), and the activity of steroid metabolic enzymes: P450 aromatase, steroid sulfatase (STS), estrogen sulfotransferase (EST) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) in 23 samples of normal endometria (CE), 18 PCOS endometria without treatment (PCOSE), 10 specimens from PCOS women with endometrial hyperplasia (HPCOSE), and 7 endometria from patients with endometrial hyperplasia not associated to PCOS (EH). The data showed lower levels of STS mRNA for PCOSE and HPCOSE (p<0.05, p<0.01, respectively) and of EST for HPCOSE and EH compared to control (p<0.05). However, higher levels for EST mRNA were obtained in PCOSE (p<0.05) versus CE. The mRNA and protein levels for P450 aromatase were undetectable in all analyzed endometria. The relationship between the activities of STS and EST was lower in PCOSE and HPCOSE (p<0.05) versus CE. The ratio between the mRNA from 17beta-HSD type 1/type 2 was higher in PCOSE (p<0.05), whereas, a diminution in the 17beta-HSD type 2 activity was observed in PCOSE (p<0.05). These results indicate that the activity of enzymes related to the steroid metabolism in analyzed PCOSE differ from those found in the CE. Consequently, PCOSE may present an in situ deregulation of the steroid metabolism.

Facilitation of decidualization by locally produced ghrelin in the human endometrium

Ghrelin acting via the growth hormone secretagogue receptor (GHS-R) stimulates GH secretion from pituitary glands. Both ligand and receptor are present in the pituitary, hypothalamus and many peripheral tissues including the uterus. This study demonstrates the cyclical expression of GHS-R and ghrelin in human endometrium. mRNA and protein for ghrelin and GHS-R were examined using RT-PCR and immunohistochemistry. Both ghrelin and GHS-R mRNA levels were highest in the secretory phase, with lower levels in the mid-proliferative phase and even lower expression in the menstrual phase. Immunoreactive ghrelin and GHS-R were confined predominantly to glandular epithelial and stromal cells with the greatest intensity of staining in secretory phase samples, consistent with the RT-PCR data. Additionally, we examined ghrelins effect on the decidualization of human endometrial stromal cells (HESCs) combined with sex steroid and cAMP treatments using prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP-1) production as markers of decidualization. Ghrelin administered in combination with sex steroids to HESC, resulted in an increase in PRL and IGFBP-1 production above that obtained with cAMP, or sex steroids alone (P<0.001) whereas ghrelin in combination with cAMP inhibits the action of cAMP. These findings have potential clinical applications for the regulation of fertility.

Aromatase expression in endometriotic tissues and its relationship to clinical and analytical findings

OBJECTIVE

To study the relationship between aromatase expression in endometriotic tissues and clinical and laboratory findings.

DESIGN

Prospective basic and clinical research.

SETTING

University hospital.

PATIENT(S)

Sixty-two women with endometriosis, and 12 without endometriosis.

INTERVENTION(S)

Conservative surgery, or hysterectomy and adnexectomy, along with an immunohistochemical study of aromatase in endometriotic and nonendometriotic tissues.

MAIN OUTCOME MEASURE(S)

Symptoms of the disease, ultrasound and surgical findings, values of tumor markers, steroids and immunoglobulins, and recurrences after surgery.

RESULT(S)

We observed positive immunohistochemical expression for aromatase in endometriotic tissues from 38 patients (61.3%). Aromatase expression was negative in the rest of the tissues studied and in the 12 cases without endometriosis. Aromatase-positive patients had a higher number of endometriomas, more bilaterality, and more moderate-to-severe chronic pelvic pain. Also, infertility and associated leiomyomas were more frequent in these patients, though without significant differences. There were no differences in recurrence of the disease 1 year later. Estradiol and PRL levels were significantly higher, and IgG values lower, than in aromatase-negative patients. High values of blood sedimentation rate were more frequent in aromatase-negative patients.

CONCLUSION(S)

Molecular alterations such as the presence of aromatase in endometriotic tissues could be involved in the development or maintenance of endometriosis. Our findings suggest major severity, activity, and chronic pelvic pain in patients with aromatase in endometriotic tissue.

Analysis of aromatase and 17beta-hydroxysteroid dehydrogenase type 2 messenger ribonucleic acid expression in deep endometriosis and eutopic endometrium using laser capture microdissection

OBJECTIVE

To investigate mRNA expression of aromatase and 17beta-hydroxysteroid dehydrogenase type 2 (17betaHSD2) in epithelial and stromal cells from eutopic and ectopic endometrium of patients with deep endometriosis.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENT(S)

Patients with deep endometriosis and fertile women with macroscopically normal pelvic cavities.

INTERVENTION(S)

During surgery, 30 endometrial and 16 endometriotic samples were obtained from 30 patients with deep endometriosis. Control endometrial samples were obtained from 24 fertile women with macroscopically normal pelvic cavities who underwent laparoscopic tubal ligation or reversal of tubal sterilization. Epithelial cells and stromal cells from endometrial or endometriotic tissues were microdissected using laser capture microdissection.

MAIN OUTCOME MEASURE(S)

Expression levels of aromatase and 17betaHSD2 mRNA in microdissected epithelial and stromal cells were determined using quantitative real-time reverse transcriptase polymerase chain reaction.

RESULT(S)

Aromatase mRNA expression was significantly higher in epithelial cells than in stromal cells in both eutopic and ectopic endometrium obtained from endometriosis patients. In the ectopic endometrium of 8 patients (8/16, 50%), 17betaHSD2 expression was not detected in either epithelial or stromal cells. In eutopic endometrium from endometriosis patients, 17betaHSD2 expression in epithelial cells was significantly increased during the early, middle, and late secretory phases compared with the late proliferative phase, whereas no significant cyclical difference was detected in control endometrium.

CONCLUSION(S)

Local estrogen concentration may be much higher in epithelial cells than in stromal cells in deep endometriotic tissue.

Aromatase and cyclooxygenase-2 expression in endometrial polyps during the menstrual cycle

OBJECTIVES

To study the changes in aromatase, Ki-67 and cyclooxygenase-2 (COX-2) expression during the menstrual cycle in both endometrial polyps and normal endometria.

PATIENTS AND METHODS

Paraffin-embedded tissue samples from 118 premenopausal patients were submitted to immunohistochemistry for measurement of aromatase, COX-2 and Ki-67 expression. Fifty cases of endometrial polyps and 68 cases of disease-free endometrium were included.

RESULTS

The presence of aromatase expression was significantly higher in endometrial polyps than in disease-free endometria. On the other hand, changes in COX-2 and Ki-67 expression followed a similar pattern during the menstrual cycle in both groups, expression peaking during the proliferative phase and falling during the late luteal phase.

CONCLUSION

A significantly higher proportion of endometrial polyps express aromatase compared with disease-free endometrium; however, no correlation was found between aromatase expression and changes in either Ki-67 or COX-2 expression during the menstrual cycle.

Effects of aromatase inhibitors on proliferation and apoptosis in eutopic endometrial cell cultures from patients with endometriosis

OBJECTIVE

To study the effect of letrozole (Let) and anastrozole (Anas) on apoptosis and cell proliferation in epithelial endometrial cells (EEC) from patients with endometriosis (EDT).

DESIGN

Prospective study.

SETTING

Research institute and clinical fertility center.

PATIENT(S)

Eighteen women with untreated EDT.

INTERVENTION(S)

Biopsy specimens of eutopic endometrium were obtained from all subjects. Apoptosis and cell proliferation were examined in EEC after incubation with Let or Anas.

MAIN OUTCOME MEASURE(S)

Percentage of apoptotic cells (ApC) was evaluated by the acridine orange-ethidium bromide technique; cell proliferation was assessed by 3H-thymidine incorporation.

RESULT(S)

Treatment with Let 10 nM and Let 100 nM enhanced values of ApC in cultures from EDT patients. Epithelial endometrial cells treated with Anas 100 nM or Anas 500 nM showed a statistically significant induction on apoptosis levels. Cultures treated with Let 1 nM or Anas 50 nM did not show any significant differences in ApC levels compared with basal conditions. 3H-Thymidine uptake was down regulated by Let 10 nM and Let 100 nM. Similarly, Anas 100 nM and Anas 500 nM showed a significantly lower degree of cell proliferation in EEC. Lower concentrations of Let and Anas did not induce any significant change in cell proliferation rates.

CONCLUSION(S)

Our results show that Let and Anas produced a significant and positive effect on apoptosis and cell proliferation on EEC from EDT patients. These findings support the further investigation of aromatase inhibitors as a treatment option in EDT.

A predictive model for endometriosis

BACKGROUND

Aromatase is the key enzyme in the process of estrogen biosynthesis from the precursor androgen. Recently, aromatase has been found to be aberrantly expressed in eutopic endometrium of patients suffering from endometriosis. This finding has prompted speculation about the contribution of this enzyme to the prediction of this disease.

METHODS

We prospectively aimed to evaluate whether endometrial biopsy, prior to laparoscopy in symptomatic women to screen for the presence of aromatase by real-time RT-PCR and immunohistochemistry, combined with select patients' characteristics, is of value to predict endometriosis.

RESULTS

Of 48 consecutive symptomatic and eligible patients, 25 (52.1%) exhibited endometriosis and 23 (47.9%) were disease-free. A multiple logistic regression model revealed that 95.5% of patients whose eutopic endometrium was found to be positive for aromatase mRNA as well as immunohistochemically detected protein and who were additionally suffering from moderate to severe dysmenorrhoea (visual analogue scale score >4/10) exhibited endometriosis at laparoscopy.

CONCLUSIONS

These findings provide direct evidence that screening for eutopic endometrial aromatase in combination with clinical data could be of discriminative value in the prediction of disease.

Laboratory testing for endometriosis

BACKGROUND

Typically, endometriosis is diagnosed surgically by laparoscopy. CA-125 is the principal serum marker used in the diagnosis and management of late-stage endometriosis. The search for a body fluid marker of early stage disease has included studies of serum, peritoneal fluid (PF), and/or tissue levels of secretory proteins, cell adhesion molecules, cytokines, tumor necrosis and vascular endothelial growth factors (VEGFs), chemokines, antiendometrial antibodies, autoantibodies to oxidized lipoproteins, aromatase P-450 expression, cytokeratins, and hormone receptors. We compared the diagnostic accuracy and clinical utility of these various types of substances in the non-surgical identification of patients with endometriosis.

METHOD

We reviewed the MEDLINE database for all publications on serum, peritoneal fluid and tissue markers of endometriosis.

RESULTS

Except for serum interleukin (IL)-6 and peritoneal fluid tumor necrosis factor (TNF)-alpha levels, the diagnostic accuracy of other markers of endometriosis was either similar or worse than that of CA-125 (sensitivity 24-94%; specificity 83-93%). The diagnostic accuracy of IL-6 and TNF-alpha was 90-100% (sensitivity) and 67-89% (specificity).

CONCLUSION

CA-125 has limited diagnostic accuracy in the identification of early stage endometriosis and none of the other markers we reviewed dramatically outperformed CA-125 in this regard with the possible exception of serum IL-6 and peritoneal fluid TNF-alpha levels.

Non-invasive methods of diagnosis of endometriosis

PURPOSE OF REVIEW

Laparoscopy is the gold standard for the diagnosis of endometriosis but the need for visual evidence of the disease is a major stumbling-block for both effective clinical management of affected patients as well as for research into this common and debilitating reproductive disease. Laparoscopy is invasive and often causes a delay in diagnosis and treatment, especially in symptomatic teenagers and young women. Moreover, the visual inspection of the pelvis has major limitations, particularly for the diagnosis of retroperitoneal lesions. It is therefore not surprising that considerable efforts are being made to improve imaging techniques and to evaluate the diagnostic value of potential molecular markers of disease.

RECENT FINDINGS

High-resolution transvaginal ultrasonography and, in selected cases, magnetic resonance imaging improve the diagnosis of retroperitoneal pelvic endometriosis as well as the identification of lesions that involve pelvic organs. A variety of serum and endometrial markers are being evaluated for their diagnostic potential, particularly in endometriosis associated infertility. The first gene profiling studies are showing positive results and proteomic technology is being applied to identify novel diagnostic protein expression patterns.

SUMMARY

Current imaging techniques, such as transvaginal ultrasonography, are useful to screen the pelvis for the presence of retroperitoneal endometriosis but fail to diagnose peritoneal lesions, small ovarian endometriomas and adhesions. Postgenomic technologies and identification of novel serum and endometrial markers are likely to revolutionize future diagnosis of endometriosis.

C6 cells express a sodium-calcium exchanger/GM1 complex in the nuclear envelope but have no exchanger in the plasma membrane: comparison to astrocytes

Previous work demonstrated the presence of an isoform of Na(+)/Ca(2+) exchanger in the nuclear envelope of neurons and NG108-15 cells that is tightly associated with GM1 ganglioside and potentiated by the latter. This contrasted with the Na(+)/Ca(2+) exchanger(s) in the plasma membrane, which were suggested to associate more loosely with GM1. To study these aspects of Na(+)/Ca(2+) exchanger expression in nonneuronal neural cells, we have examined nuclear and plasma membrane exchanger patterns in astrocytes and C6 cells, a glia-derived line. We find both cell types contain the tightly associated exchanger/GM1 complex in the nuclear envelope but, surprisingly, only astrocytes possess Na(+)/Ca(2+) exchanger activity in the plasma membrane. This is the first reported example of a cell (C6) with Na(+)/Ca(2+) exchangers in the nuclear envelope but not in the plasma membrane. RT-PCR established the presence of the NCX1 subtype in C6 cells and both NCX1 and NCX2 in astrocytes. Comparison was made with NG108-15 cells, which have Na(+)/Ca(2+) exchangers in both nuclear and plasma membranes, and Jurkat cells, which have no Na(+)/Ca(2+) exchanger in either membrane. Culturing of C6 cells in the presence dibutyryl-cAMP caused upregulation of a high molecular weight isoform of the exchanger together with GM1 in the nuclear envelope, resulting in significant elevation of Na(+)/Ca(2+) exchanger activity in the latter. Application of exogenous GM1 to nuclei from non-treated cells also potentiated exchanger activity, although to a lesser degree. The Na(+)/Ca(2+) exchanger/GM1 complex occurs in the inner membrane of the nuclear envelope, suggesting a functional role in transferring Ca(2+) between nucleoplasm and the envelope lumen.

Steroid receptor and aromatase expression in baboon endometriotic lesions

OBJECTIVE

To evaluate steroid receptor and aromatase gene expression in endometriotic lesions, and determine the effects of endometriosis on uterine receptivity in a baboon model for endometriosis.

DESIGN

Prospective study to determine the expression of steroid receptors, and aromatase in ectopic endometriotic lesions and endometrial genes in the eutopic endometrium of baboons with induced endometriosis by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry.

SETTING

University research laboratory and primate research facility.

ANIMAL(S)

Normally cycling baboons inoculated intraperitoneally with menstrual endometrium to induce endometriosis.

INTERVENTION(S)

Endometriotic lesions were resected during laparotomy, and endometrium was obtained by endometrectomy or after hysterectomy.

MAIN OUTCOME MEASURE(S)

Steroid receptor and aromatase expression by RT-PCR and immunocytochemistry in endometriotic lesions and glycodelin and alpha-smooth muscle actin expression and localization in endometrium after chorionic gonadotropin (CG) stimulation.

RESULT(S)

This study demonstrated that estrogen receptor-alpha (ERalpha) and progesterone receptor (PR) were expressed in both ectopic and eutopic endometrium between 1 and 10 months after inoculation. In contrast, ERbeta was only expressed in the ectopic endometriotic lesions. Aromatase expression was only evident in lesions obtained 10 months after inoculation. Infusion of CG during the luteal phase failed to induce the expression of glycodelin in the glandular epithelium or alpha-smooth muscle actin (alpha-SMA) in stromal cells in animals with endometriosis as early as 1 and 4 months after inoculation.

CONCLUSION(S)

The ERbeta expression is selectively up-regulated in the endometriotic lesions at all stages of the disease, whereas aromatase expression is not evident until the disease progresses. However, expression of uterine receptivity markers was down-regulated as early as 1 and 4 months after inoculation.

Noninvasive diagnosis of endometriosis: the role of imaging and markers

Endometriosis is defined by the presence of endometrial tissue outside the uterus. Clinical and basic research in endometriosis has been hampered severely by the lack of accurate noninvasive diagnostic techniques. Transvaginal ultrasonography, MRI, and endometrial and serum markers have the potential to facilitate the diagnosis and can be useful in the follow-up of patients. Endometriosis research has entered the postgenomic era, and powerful genomic and proteomic technology is being applied in the search for novel diagnostic and therapeutic approaches. This article explores the recent advances in imaging techniques and the development of diagnostic molecular markers of endometriosis.