Jean-Christophe Lousse

Laparoscopic management of endometriomas using a combined technique of excisional (cystectomy) and ablative surgery

OBJECTIVE To describe and evaluate a new technique of laparoscopic treatment of endometriomas that combines excisional and ablative surgery. DESIGN Descriptive and prospective study. SETTING Gynecology research unit in a university hospital. PATIENT(S) Fifty-two women under 35 years of age presenting for infertility and/or pelvic pain with endometriomas larger than 3 cm were included in the study. None had undergone any surgery for endometriosis. INTERVENTION(S) A large part of the endometrioma wall was first excised according to the cystectomy technique. After this first step, CO(2) laser was used to vaporize the remaining 10%-20% of the endometrioma wall close to the hilus. MAIN OUTCOME MEASURE(S) The feasibility of this new technique was assessed. Ovarian volume and antral follicle count (AFC) were compared between operated ovaries and nonoperated ovaries of patients with endometriosis and controls (women with male factor infertility). RESULT(S) The combined technique was possible in all cases. The volume of the ovary after the combined technique was similar to that of the contralateral normal ovary, as well as to that observed in infertile women without endometriosis presenting for male factor infertility. The AFC on day 2-5 showed the same number of antral follicles in all subgroups. Histopathology of the excised part of the endometrioma revealed the presence of follicles in only one case (2%). The pregnancy rate was 41% at a mean follow-up of 8.3 months. Recurrence of a small endometrioma was observed in only one case (2%). CONCLUSION(S) The combined technique (stripping and ablation) has proved not to be deleterious to the ovary.

Potential involvement of iron in the pathogenesis of peritoneal endometriosis

The aim of this study is to review the current literature associating endometriosis with iron and to discuss the potential causes and consequences of iron overload in the pelvic cavity. Indeed, iron is essential for all living organisms. However, excess iron can result in toxicity and is associated with pathological disorders. In endometriosis patients, iron overload has been demonstrated in the different components of the peritoneal cavity (peritoneal fluid, endometriotic lesions, peritoneum and macrophages). Animal models allow us to gather essential information on the origin, metabolism and effect of iron overload in endometriosis, which may originate from erythrocytes carried into the pelvic cavity mainly by retrograde menstruation. Peritoneal macrophages play an important role in the degradation of these erythrocytes and in subsequent peritoneal iron metabolism. Iron overload could affect a wide range of mechanisms involved in endometriosis development, such as oxidative stress or lesion proliferation. In conclusion, excess iron accumulation can result in toxicity and may be one of the factors contributing to the development of endometriosis. Treatment with an iron chelator could thus be beneficial in endometriosis patients to prevent iron overload in the pelvic cavity, thereby diminishing its deleterious effect.

Absence of aromatase protein and mRNA expression in endometriosis.

BACKGROUND Aromatase has been reported to be involved in estrogen biosynthesis and expressed in eutopic and ectopic endometrium of endometriosis patients. The objective of the present study was to investigate its expression and localization in three distinct types of endometriosis. METHODS Human peritoneal, ovarian and rectovaginal endometriotic lesions and matched eutopic endometrium were collected from patients during laparoscopy. Aromatase protein localization (immunohistochemistry, n = 63) and mRNA expression [quantitative polymerase chain reaction (Q-PCR), n = 64] were assessed. RESULTS No aromatase protein was detected by immunohistochemistry in either the glandular or stromal compartment of endometriotic lesions or eutopic endometrium, while it was strong in placental syncytiotrophoblasts, granulosa and internal theca cells from pre-ovulatory follicles, and luteal cells from corpus luteum. By Q-PCR, low but discernible levels of aromatase expression were found in endometriomas, probably due to follicular expression. Transcripts for aromatase were barely detectable in only a few peritoneal and rectovaginal endometriotic lesions, and a few eutopic endometrium samples, probably due to contaminating surrounding tissues (adipose tissue, intact peritoneum). CONCLUSIONS Unlike previous studies, we observed no aromatase protein in any of the endometriosis types, and barely detectable aromatase mRNA expression, suggesting that locally produced aromatase (within endometriotic lesions) may be less implicated in endometriosis development than previously postulated. Potential factors responsible for these discrepancies are discussed.

Peritoneal endometriosis is an inflammatory disease.

Peritoneal endometriosis is a chronic inflammatory disease characterized by increased numbers of peritoneal macrophages and their secreted products. Inflammation plays a major role in pain and infertility associated with endometriosis, but is also extensively involved in the molecular processes that lead to peritoneal lesion development. Peritoneal oxidative stress is currently thought to be a major constituent of the endometriosis-associated inflammatory response. Excessive production of reactive oxygen species, secondary to peritoneal influx of pro-oxidants such as heme and iron during retrograde menstruation, may induce cellular damage and increased proinflammatory gene expression through nuclear factor-kappa B activation. In particular, prostaglandin biosynthetic enzyme expression is regulated by this transcriptional factor, and increased peritoneal prostaglandin concentrations have been demonstrated in endometriosis. In the light of available data collected from patient biopsies, as well as in vitro and in vivo studies, the respective involvement and potential molecular interactions of iron, nuclear factor-kappa B and prostaglandins in the pathogenesis of endometriosis are explored and discussed. The key role of peritoneal macrophages is emphasized and potential therapeutic targets are examined.

Iron storage is significantly increased in peritoneal macrophages of endometriosis patients and correlates with iron overload in peritoneal fluid

OBJECTIVE To further investigate peritoneal iron disruption in endometriosis by studying iron storage in peritoneal macrophages of patients with endometriosis compared with controls. DESIGN Cross-sectional study. SETTING Academic gynecology research unit in a university hospital. PATIENT(S) Fifty patients undergoing laparoscopy. INTERVENTION(S) Collection of peritoneal fluid samples (N = 50) from patients with (n = 27) and without (n = 23) endometriosis undergoing laparoscopy. MAIN OUTCOME MEASURE(S) Quantification of peritoneal macrophage ferritin by immunocytochemical staining and immunodensitometry and measurement of peritoneal iron, transferrin, ferritin, and prohepcidin concentrations. RESULT(S) The optical density of peritoneal macrophage ferritin staining was statistically significantly higher in endometriosis patients than in controls. Higher iron concentrations, transferrin saturations, and ferritin concentrations were also detected in case of endometriosis. A statistically significant positive correlation was found between the optical density of macrophage ferritin staining and peritoneal iron concentrations in endometriosis and control patients. CONCLUSION(S) Iron storage is statistically significantly increased in peritoneal macrophages of patients with endometriosis and correlates with iron overload in peritoneal fluid. The potential implications of iron accumulation in peritoneal macrophages in case of endometriosis are discussed.

Inhibition of steroid sulfatase decreases endometriosis in an in vivo murine model

BACKGROUND Steroid sulfatase (STS) is involved in estrogen biosynthesis and expressed in eutopic and ectopic endometrium of disease-free and endometriosis patients. The present study was designed to investigate its role in endometriosis development. METHODS Human endometrial explants were cultured on inserts for 24 h to assess the effectiveness of an STS inhibitor (STS-I), estradiol-3-O-sulfamate (E2MATE), on STS activity in endometrial tissue. Endometriosis was induced in mice, and E2MATE (or vehicle alone) was given orally for 21 days. Plasma estradiol levels were measured, and STS activity was assessed in murine organs (uterus, liver and leukocytes) and in lesions. Lesion number, weight and size (morphometry) were quantified. Lesion STS and progesterone receptor (PR) expression, proliferation and apoptosis rates were determined by immunohistochemistry. RESULTS In vitro, addition of 1 µM E2MATE to the culture medium resulted in decreased STS activity in endometrial explants (P < 0.001). Treatment of mice with E2MATE (1.0 and 0.5 mg/kg) did not modify plasma estradiol levels, but inhibited STS activity in murine uterus (P < 0.05), liver (P < 0.001) and leukocytes (P < 0.001), as well as in induced lesions (P < 0.05). E2MATE reduced lesion weight (P < 0.01) and size (P < 0.05), but had no impact on proliferation or apoptosis rates, nor STS protein expression. Stromal edema was observed in the uterus of animals treated with E2MATE, but not in the stroma of lesions. Increased PR expression was detected in endometriotic lesions (P < 0.001). CONCLUSIONS E2MATE was shown to effectively inhibit STS activity in endometrial tissue in vitro. In vivo, E2MATE decreased endometriosis development without affecting systemic estradiol levels. Use of STS-I could therefore be of potential interest in endometriosis treatment.

Expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in human endometrial stromal and epithelial cells is regulated by interferon-gamma but not iron.

Background/Aims: Endometrial cells are chronically exposed to iron due to cyclic menstrual bleeding. Iron induces expression of adhesion molecules in endothelial cells. The purpose of this study was to investigate iron incorporation by human endometrial cells and to test whether iron may stimulate expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1. Methods: Endometrial stromal and epithelial cells were cultured in medium alone or supplemented with INF-γ or transferrin (Tf). Iron incorporation by cells was quantified by densitometry of ferritin immunostaining. ICAM-1 and VCAM-1 expression were evaluated at the transcriptional level by real-time RT-PCR. Membrane-bound and soluble protein levels of ICAM-1 were measured by quantitative immunohistochemistry and ELISA, respectively. Results: Tf induced a significant increase in ferritin immunostaining in both endometrial cell types. Endometrial cells treated with INF-γ expressed more ICAM-1 and VCAM-1 than untreated cells. By contrast, Tf treatment did not alter ICAM-1 and VCAM-1 expression in cultured endometrial cells. Conclusions: Endometrial cells are able to incorporate iron from Tf and to metabolize it to ferritin. Iron, unlike interferon-γ, does not appear to be involved in the regulation of ICAM-1 and VCAM-1 expression in cultured endometrial cells.

Laparoscopic observation of spontaneous human ovulation

We report laparoscopic observation of spontaneous human ovulation, illustrated by protrusion of the mature follicle and oocyte release into the peritoneal cavity.

Evaluation of Estrogen Treatment in an Immunodeficient Mouse Endometriosis Model.

Background/Aims: Endometriosis is known to be an estrogen-dependent disease. However, only a few studies have analyzed the effect of estrogen treatment in mice xenotransplanted with human endometrium. The objective of this study was to adapt a previously developed heterologous murine model to the study of estrogens and test the impact of estrone treatment on endometriosis development. Methods: Human proliferative endometrium was xenotransplanted into the peritoneal cavity of castrated immunodeficient mice. These mice were treated with estrogens by means of subcutaneous estrone-releasing pellets. The effect of estrone on estradiol level, uterine histology and endometriosis development was evaluated after 21 days. Results: Bioactivity of estrone pellets and their metabolization into estradiol were demonstrated. However, there was no impact on endometriosis development (no difference in lesion number, weight, size or fluorescence). This lack of response was not due to absence of estrogen receptor expression, since strong expression was found in all lesions harvested. Surprisingly, castrated nontreated mice presented with lesions showing high proliferative activity, similar to lesions found in treated mice (around 30%). Conclusion: The high proliferation observed in lesions recovered from ovariectomized nontreated mice questions the utility of using estrogens in heterologous murine models.

Non-gestational Malignant Placental Site Trophoblastic Tumor of the Ovary in a 4-Year-Old Rhesus Monkey

We report a case of ovarian malignant intermediate-type trophoblastic tumor in a clinically normal, nonpregnant 4-year-old rhesus monkey (Macaca, mulatta). A large solid lobulated mass replaced the right ovary and filled the pelvis. Multiple metastases were observed within the lungs and the liver. The tumor was histologically identified as predominantly composed of intermediate trophoblastic cells, without prominent hemorrhages and the classic bilaminar pattern of cyto- and syncytiotrophoblastic cells characteristic of choriocarcinoma. Immunohistochemical analysis showed the presence of placental lactogen hormone in many tumor cells and chorionic gonadotropin in a few multinucleated cells consistent with syncytiotrophoblastic differentiation. No other germ cell differentiation was identified in the pelvis mass nor in the metastases. In the absence of previous and present pregnancy, this neoplasm has to be considered as a nongestational malignant placental site trophoblastic tumor of the ovary.