Endometriosis: abnormal endometrium and dysfunctional immune response

Contribution of Bone Marrow-Derived Stem Cells to Endometrium and Endometriosis

Bone marrow-derived cells (BMDCs) can differentiate into nonhematopoietic cells, suggesting that BMDCs may contribute to the maintenance of multiple tissues. Donor-derived bone marrow cells have been identified in human uterine endometrium. Here, two murine models were used to investigate the contribution of nonendometrial stem cells to endometrium. We investigate whether BMDCs can localize to uterine endometrium and to endometriosis. After bone marrow transplantation, male donor-derived bone marrow cells were found in the uterine endometrium of female mice. Although uncommon (<0.01%), these cells can differentiate into epithelial cells. After generation of experimental endometriosis by ectopic endometrial implantation in the peritoneal cavity, bone marrow from LacZ transgenic mice was used for transplantation. LacZ expressing cells were found in the wild-type ectopic endometrium implanted in the peritoneal cavity of hysterectomized LacZ transgenic mice. The repopulation of endometrium with bone marrow-derived stem cells may be important to normal endometrial physiology and also may help to explain the cellular basis for the high long-term failure of conservative alternatives to hysterectomy. The examination of a sexually dimorphic organ such as the uterus demonstrates the ability of male bone marrow, which cannot harbor circulating endometrial cells, to generate endometrium de novo and proves their mesenchymal stem cell origin. Finding Y chromosome bearing endometrial cells demonstrates the potential to recapitulate embryonic developmental pathways that were never activated in males; BMDCs may have vast regenerative capacity. Additionally, the ability of stem cells to engraft endometriosis has implications for the origin and progression of this disease. Ectopic differentiation of stem cells may be a novel mechanism of disease. Disclosure of potential conflicts of interest is found at the end of this article.

Tyrosine receptor kinase B (TrkB) protein expression in the human endometrium

Tyrosine kinase receptor B (TrkB) gene expression, a neurotrophic factor receptor expressed in the brain and ovary, has recently been identified in deep infiltrating endometriosis by gene array. TrkB is thought to be important in resistance to anchorage independent apoptosis (ANOIKIS) and thus could be important in the pathogenesis of endometriosis. However, TrkB protein expression in the eutopic endometrium of women with and without endometriosis is unknown. Therefore, we examined TrKB protein expression in the endometrium by Western blot (n = 50) and immunohistochemistry (n = 17). Immunoblots of endometrial biopsies were prepared from women with endometriosis (n = 21) vs. healthy controls (n = 29) undergoing benign gynecological surgery at McMaster University Medical Centre. TrkB protein expression was significantly higher in immunoblots from women with endometriosis compared to women without endometriosis. In samples of archived paraffin-embedded endometrial tissue TrkB was localized to the cytoplasm of epithelial cells of the eutopic endometrium from women with endometriosis (n = 7) and without endometriosis (n = 10). We conclude that TrkB protein is expressed in human endometrium. Our results also suggest that TrkB expression may be greater in women with endometriosis compared to women without endometriosis.

Pentoxifylline therapy after laparoscopic surgery for different stages of endometriosis: a prospective, double-blind, randomized, placebo-controlled study

STUDY OBJECTIVE

To evaluate the effects of pentoxifylline administration on patients with different stages of endometriosis on whom laparoscopy was performed.

DESIGN

Prospective, double-blind, randomized, placebo-controlled clinical (Canadian Task Force classification I).

SETTING

University and private hospitals.

PATIENTS

Eighty-eight women, all with infertility, some with dysmenorrhea, dyspareunia, or pelvic pain, on whom a laparoscopic diagnosis of endometriosis was made.

INTERVENTIONS

The treatment group received 800 mg pentoxifylline daily for 6 months immediately after surgery. The control group received placebo capsules. All patients were followed-up for 1 year thereafter.

MEASUREMENTS AND MAIN RESULTS

A comparison of pregnancy rate and recurrence of signs and symptoms in the 2 groups was performed. Forty-three patients were studied in the pentoxifylline group and 45 in the placebo group. The cumulative pregnancy rate was 39.5% and 35.6% in the treatment and control groups, respectively. The overall recurrence of signs and symptoms was 14% in the former group and 15.6% in the latter. There were no statistically significant differences between the 2 groups in rates of pregnancy and recurrence (p = .700 and .832, respectively). Nor was there any significant statistical difference between the same stages in the 2 groups regarding immunomodulation.

CONCLUSIONS

According to the results of this study, and while keeping in mind that appropriate surgery is the main aspect of endometriosis treatment, there is no evidence that immunomodulation with pentoxifylline aids fertility or lessens recurrence of signs and symptoms in women with different stages of endometriosis (i.e., minimal, mild, moderate, or severe).

Endometriosis: epidemiology and aetiological factors

Estimates of the frequency of endometriosis vary widely. Based on the few reliable data, the prevalence of the condition can reasonably be assumed to be around 10%. Although no consistent information is available on the incidence of the disease, temporal trends suggest an increase among women of reproductive age. This could be explained-at least in part-by changing reproductive habits. Numerous epidemiological studies have indicated that nulliparous women and women reporting short and heavy menstrual cycles are at increased risk of developing endometriosis; data on other risk factors are less consistent. These epidemiological findings strongly support the menstrual reflux hypothesis. Additional evidence in favour of this theory includes the demonstration of viable endometrial cells in the menstrual effluent and peritoneal fluid, experimental implantation and growth of endometrium within the peritoneal cavity, observation of some degree of retrograde menstruation in most women undergoing laparoscopy during menses, and an association between obstructed menstrual outflow and endometriosis.

Expression of motility-related molecule Cdc42 in endometrial tissue in women with adenomyosis and ovarian endometriomata

OBJECTIVE

To evaluate Cdc42 expression in eutopic and ectopic endometrial tissue in patients with adenomyosis and ovarian endometriotic cysts compared with patients without endometriosis.

DESIGN

Experimental retrospective study.

SETTING

University hospital.

PATIENT(S)

Twenty-four patients with adenomyosis, 19 with ovarian endometriomata, and 9 with fibroids or benign ovarian cysts.

INTERVENTION(S)

Hysterectomy and bilateral oophorectomy.

MAIN OUTCOME MEASURE(S)

Immunostaining for Cdc42 of eutopic and ectopic endometrial tissues.

RESULT(S)

In eutopic endometrium of patients with adenomyosis and with fibroids or benign ovarian cysts, the intensity of Cdc42 immunostaining was weaker, especially in the specialized stromal cells, compared with cases with ovarian endometriosis (chi(2) test, P=.003). Expression of Cdc42 in eutopic endometrium showed a trend to be higher in the secretory than in the proliferative phase and in patients with ovarian endometriotic cysts compared with patients with adenomyosis (unpaired t test, P=.005), especially in the proliferative phase.

CONCLUSION(S)

An abnormally high expression of Cdc42 in eutopic endometrium in the secretory phase may contribute to the development of ovarian endometriosis, but it does not seem to be involved in the pathogenesis of adenomyosis.

Regulation of FAS ligand expression by chemokine ligand 2 in human endometrial cells

Human endometrium is a dynamic tissue under the influence of numerous hormones, growth factors, and cytokines interacting to maintain a balance of cellular growth, differentiation, and apoptosis. We have previously demonstrated that several factors including interleukin-8, extracellular matrix, and steroid hormones modulate FASLG, one of the apoptotic molecules, in human endometrium. Chemokine ligand 2 (CCL2), a monocyte chemoattractant and activating factor, is a cytokine involved in endometrial function. CCL2 is elevated in the peritoneal fluid of women with endometriosis. We hypothesize that increased levels of CCL2 in the endometriotic environment may upregulate FASLG expression in human endometrial stromal cells and induce a local immunotolerance in endometriosis. To test our hypothesis, we studied the in vitro regulation of FASLG expression and apoptosis by CCL2 in endometrial stromal cells. Western blot analysis revealed that CCL2 upregulated FASLG protein expression in cultured endometrial stromal cells. Based on semiquantitative RT-PCR analysis, CCL2 did not alter either FAS or FASLG mRNA expression in endometrial stromal cells. Immunocytochemistry results from the same cells treated with CCL2 demonstrated upregulation of FASLG protein expression. CCL2 did not change rate of apoptosis in endometrial stromal cells as evaluated by TUNEL assay. However, an increased apoptotic rate was detected in Jurkat (T lymphocytes) cells cocultured with endometrial stromal cells previously treated with CCL2. We speculate that increased FASLG expression by CCL2 may induce apoptosis of T lymphocytes and thus produce an immunotolerant environment for the development of ectopic implants.

Medical management of endometriosis

Current approved medical therapies for endometriosis rely on drugs that suppress ovarian steroids and induce a hypoestrogenic state, which determines the atrophy of the ectopic endometrium. Gonadotropin-releasing hormone analogs such as danazol, progestogens and estrogen-progestin combinations have all proven effective in relieving pain and reducing the extent of endometriotic implants. However, symptoms often recur after discontinuation of therapy and hypoestrogenism-related side effects limit the long-term use of most medications. Recently, knowledge of the pathogenesis of endometriosis, particularly at the molecular level, has grown substantially, providing a rational basis for the development of new drugs with precise targets that may be safely administered over the long term.

The endometria of patients with endometriosis show higher expression of class I human leukocyte antigen than the endometria of healthy women

OBJECTIVE

To compare the expression of class I human leukocyte antigen (HLA I) in endometrial samples from patients with and without endometriosis.

DESIGN

Cross-sectional study.

SETTING

Acute-care teaching hospital in Barcelona, Spain.

PATIENT(S)

The endometriosis group included 32 patients for whom the only diagnosis during an operation was endometriosis. The control group included 20 women who underwent a laparoscopy and in whom no evidence of endometriosis or any other genital disease was seen.

INTERVENTION(S)

Samples of endometrium were obtained by curettage and immediately frozen. A pan-HLA I mouse antihuman IgG2a monoclonal antibody was used for immunohistochemical study.

MAIN OUTCOME MEASURE(S)

Frequency of positive glandular and stromal cells was evaluated in each section.

RESULT(S)

A significantly higher expression of HLA I in the endometriosis group than in controls, both in the glandular cells (median 100% vs. 80%) and in the stromal cells (median 60% vs. 20%), was observed.

CONCLUSION(S)

Patients with endometriosis had a significantly higher expression of HLA I molecules in endometrial cells than did the controls. This could be a possible explanation for their higher resistance to natural killer cytolysis.

Treatment of endometriosis with transvaginal ultrasound-guided drainage under GnRH analogues and recombinant interleukin-2 left in the cysts

BACKGROUND

To analyze the therapeutic results of one dose of 3 million IU of recombinant interleukin-2 (rIL-2) left intracyst (group I) versus two doses with a 1-month interval (group II) after transvaginal ultrasound (US)-guided drainage of endometriomas under the effect of GnRH analogues.

METHODS

Prospective and randomized clinical trial (helped by a random number table) at a University Hospital. Twenty-four consecutive patients with endometriomas initially sent to us for laparotomy and conservative surgery for endometriosis were included.

INTERVENTIONS

Treatment with GnRH analogues every 28 days, 3 doses. Under their effect, one or two transvaginal US-guided punctures were performed in order to aspirate the endometriomas, and 3 million IU of rIL-2 were left in the aspirated cysts each time.

MAIN OUTCOME MEASURES

CLINICAL RESULTS

two menstruations after GnRH analogues. Other secondary outcome measures were: the time until recurrence of cysts, symptoms and CA-125 >35 U/ml, and the need for further medical or surgical treatment.

RESULTS

They were moderate or good in >50% of cases with one drainage and one dose of 3 million IU of rIL-2 intracyst, but were better with a second drainage and two doses of rIL-2 (25 vs. 58.3% 'good results'). There were fewer recurrences and the interval before recurrence was longer after two doses but differences were not significant. Six patients from group I (50%) and 3 from group II (25%) needed laparotomy and conservative surgery at 17.5 +/- 8.7 months (total time of follow-up = 33 +/- 8.8 months).

CONCLUSIONS

Treatment of endometriomas with transvaginal US-guided drainage and rIL-2 left in the cysts under endometrial suppressive therapy with GnRH analogues has beneficial effects, improving clinical manifestations and avoiding some surgical therapies. The use of a higher dose of rIL-2 does not produce better results, whereas drainage + rIL-2 twice does.

Serum levels of VEGF and TNF-α and their association with C-reactive protein in patients with endometriosis

OBJECTIVE

To compare serum levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP) throughout the menstrual cycle in women with and without endometriosis and to quantify the association between these serum markers.

METHODS

Twenty five endometriosis patients (ASRM stage III-IV) and 13 controls were followed through one menstrual cycle. VEGF, TNF-alpha and CRP concentrations were measured with enzyme-linked immunosorbent assay in each of the four cycle phases (early and late proliferative and early and late secretory). Non-parametric methods and Pearson's correlation coefficients were used for statistical analysis.

RESULTS

Increased serum levels of VEGF in secretory phases and of TNF-alpha in all cycle phases were observed. A positive correlation between CRP and VEGF was found in endometriosis patients but not in controls.

CONCLUSIONS

Our results suggest that excessive systemic angiogenic activity is a feature of patients with endometriosis.

Relation between anatomical courses of the intramural portions of the uterine tubes and pelvic endometriosis

OBJECTIVE

Endometriosis may originate from implants of endometrium due to retrograde flow of menstrual blood. The flow may be stimulated by anatomical anomalies of uterine tubes or uterus. The aim of the study was to find links between anatomical courses of the intramural portions of the uterine tubes and endometriosis.

DESIGN

Retrospective comparative study.

SETTING

Academic hospital.

PATIENT(S)

Women (n = 227) operated on because of various gynecological indications.

INTERVENTION(S)

Total or subtotal abdominal hysterectomies.

MAIN OUTCOME MEASURE(S)

Pathological reports correlated with courses of the intramural parts of uterine tubes. To evaluate the intramural courses of uterine tubes, specimens were injected with barium sulfate and x-rayed.

RESULT(S)

The intramural portions were categorized into three patterns: straight, curved, or tortuous. Logistic regression identified the course of the intramural portion of the uterine tubes and the parity to be associated with endometriosis. Endometriosis was more frequent in women with straight courses and was infrequent in women with tortuous ones.

CONCLUSION(S)

We suggest that a tortuous course of the intramural portion of the uterine tubes constitutes a normal anatomical finding. It controls the retrograde flow of blood during menstruation and limits the possibility of developing endometriosis. Straight or curved intramural portions represent an anatomical abnormality that may predispose women to endometriosis.

Changes in cytokine levels of patients with ovarian endometriosis after treatment with gonadotropin-releasing hormone analogue, ultrasound-guided drainage, and intracystic recombinant interleukin-2

OBJECTIVE

To determine the changes in cytokine levels from women with endometriomas who are treated with recombinant interleukin-2 after ultrasound-guided cyst aspiration, and to relate these changes to the clinical results observed in these patients.

DESIGN

A double-blind randomized controlled trial.

SETTING

University hospital.

PATIENT(S)

Twenty-four women with endometriosis-related symptoms and endometriomas.

INTERVENTION(S)

Endometriomas in women receiving GnRH analogues and undergoing transvaginal ultrasound-guided cyst aspiration were injected with dextrose that did or did not contain recombinant interleukin-2 (IL-2). Serum samples were collected before and after treatment.

MAIN OUTCOME MEASURE(S)

Serum samples were analyzed by enzyme immunoassay to determine the levels of IL-1beta, IL-2, IL-6, IL-8, IL-10, IL-12, IL-13, and IL-17.

RESULT(S)

The cytokine levels after treatment with GnRH analogues and recombinant IL-2 were similar to the initial levels. The patients receiving GnRH analogues without IL-2 had higher IL-1, IL-2, IL-8, and IL-13 levels. Good clinical results were observed in 90% of the patients in the first group but in only 30% of the second one.

CONCLUSION(S)

Administration of recombinant IL-2 intracystically decreases cytokine production in women with endometriomas. These results have important implications for the design of future therapies based on immunomodulation, such as using higher or repeated doses of recombinant IL-2 in the cysts.

The presence of endometrial cells in the peritoneal cavity enhances monocyte recruitment and induces inflammatory cytokines in mice: implications for endometriosis

OBJECTIVE

To determine the inflammatory response in the peritoneal cavity by the presence of endometrial cells and the role of the mesothelium.

DESIGN

In vivo study using mice.

SETTING

University research laboratory.

ANIMAL(S)

Female Swiss Webster mice, 8 to 10 weeks old.

INTERVENTION(S)

Homogenous mouse endometrial epithelial and stromal cells were injected intraperitoneally. Peritoneal lavage and mesothelium were collected 4 to 72 hours after the administration.

MAIN OUTCOME MEASURE(S)

We determined the number of peritoneal macrophages, and the production and gene expression of monocyte chemotactic protein-1 (MCP-1/JE), interleukin 1alpha (IL-1alpha), and interleukin 6 (IL-6).

RESULT(S)

The intraperitoneal administration of endometrial cells increased the number of peritoneal macrophages, production of MCP-l, IL-1alpha, and IL-6, and expression of mesothelial MCP-1/JE, IL-1alpha, and IL-6 genes in recipient mice.

CONCLUSION(S)

These results suggest that retrograde menstruation could account for the increased presence of inflammatory mediators in the peritoneal cavity of women with endometriosis. The mesothelium could play an active role in endometriosis in addition to providing an attachment stratum for the endometrial cells.

The tumor necrosis factor-alpha promoter -1031C polymorphism is associated with decreased risk of endometriosis in a Japanese population

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) is a multifunctional proinflammatory cytokine, associated with various inflammatory and autoimmune diseases. Elevated TNF-alpha levels in peritoneal fluid have been reported in women with endometriosis, suggesting that TNF-alpha may be involved in the development of endometriosis. In this study, we investigated the possible association between endometriosis and the TNF-alpha gene promoter polymorphisms -238G/A, -308G/A, -857C/T, -863C/A and -1031T/C in a Japanese population.

METHODS

We compared the distribution of the -238G/A, -308G/A, -857C/T, -863C/A and -1031T/C polymorphisms in the promoter region of TNF-alpha in 130 endometriosis cases and 185 controls using PCR-RFLP analysis.

RESULTS

The allele frequencies of -238A, -308A, -857T, -863A and -1031C in controls were 2.0%, 1.3%, 19.4%, 17.0% and 18.6%, and in the cases 1.1%, 0.3%, 19.6%, 18.6% and 13.6%, respectively. No significant differences in frequencies were found between the crude endometriosis cases and controls. However, when the endometriosis group was divided into a subgroup of women with stage IV disease only, the frequency of the -1031C allele was significantly lower in this subgroup than controls.

CONCLUSIONS

The variability of the -1031T/C polymorphism of the TNF-alpha gene may be associated with susceptibility to (AUTHOR: as meant?) endometriosis.

Histomorphometric alteration and cell-type specific modulation of arylhydrocarbon receptor and estrogen receptor expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin and 17β-estradiol in mouse experimental model of endometriosis

Our purpose was to examine the effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), either singly (10 microg/kg) or with 17beta-estradiol (E2, 100 microg/kg), on the growth of endometriosis in a mouse endometriosis model by employing histo-morphometrical analysis as well as expression of arylhydrocarbon receptor (AhR) and estrogen receptor (ER). Epithelial height, stromal thickness, and proliferative activity of the endometriotic lesions were significantly increased by E2 in ovariectomized mice, whereas co-administered TCDD significantly reduced these effects. TCDD alone did not affect the proliferative activity but rather reduced the epithelial height and stromal thickness. ER expression in the luminal epithelium was decreased by E2 compared with ovariectomy alone, while TCDD significantly increased it. On the other hand, stromal ER expression was significantly increased by ovariectomy and decreased by E2, though TCDD did not further enhance this expression. These results indicate that a short-term exposure to TCDD failed to increase the growth of endometriotic lesion and the direct effect of TCDD probably depends on a cell-specific interaction with ovarian steroids mediated by their own receptors. These initial findings in intact tissue of mouse endometriosis may suggest critical roles of steroid hormones in the pathogenesis of endometriosis in relation to endocrine disruptors.

GnRH analogues, transvaginal ultrasound-guided drainage and intracystic injection of recombinant interleukin-2 in the treatment of endometriosis

We performed a double-blind, randomised controlled trial to evaluate the results of ultrasound-guided aspiration of endometriomas under the effect of GnRH analogues and a possible additional beneficial effect by leaving 600000 IU of recombinant interleukin-2 (rIL-2) in the cysts. Twenty-four women with endometriosis-related symptoms, increased values of CA-125 and transvaginal ultrasonography showing endometriomas >3 cm who were initially sent to us for laparotomy and conservative surgery for endometriosis were included. Main outcome measures were severity of symptoms, size and percentage of echographical reduction of endometriomas and CA-125 levels after 2 menses post-GnRH analogues. Secondary outcome measures were the time until recurrence of abnormal parameters and the need for surgery after treatment. We found moderate clinical results after treatment with drainage plus GnRH analogues and significantly improved results in women having received rIL-2 intracystically. There were no side effects. Two out of 3 previously infertile patients became pregnant after therapy. Though the rates of recurrence of endometriomas >or=3 cm were similar in both groups, the period until recurrence was significantly greater when rIL-2 was used, and the rates of recurrence of symptoms and increased CA-125 values were also significantly lower in patients who received rIL-2. Surgery was finally performed on 10 patients (4 with and 6 without previous rIL-2 treatment) during follow-up (30 +/- 12.7 months). These findings led to the conclusion that transvaginal ultrasound-guided puncture and aspiration of endometriomas under endometrial suppressive therapy with GnRH analogues have some value for endometriosis treatment, improving the clinical manifestations and avoiding some surgical therapies, and that rIL-2 left in the cyst increases these beneficial effects significantly.

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.

Blood leukocyte subsets are modulated in patients with endometriosis

OBJECTIVE

To determine whether blood leukocyte populations could be modulated in endometriosis.

DESIGN

Case-control study.

SETTING

Eight clinical institutions of the Montreal area.

PATIENT(S)

Women with regular menstrual cycles who underwent laparoscopy or laparotomy between 1997 and 2001 and who were not under hormonal treatment for at least 3 months were selected. This study includes 175 cases and 131 controls.

MAIN OUTCOME MEASURE(S)

The proportion of blood leukocytes expressing markers for T, B lymphocytes, monocytes, or natural killer (NK) cells were compared by flow cytometric analysis between cases and controls.

RESULT(S)

Age and parity were identified as important confounders. Given that smoking, history of acute infection, and previous use of oral contraceptives strongly correlate with the level of some blood leukocyte populations, these parameters were taken into account in addition with age and parity when the level of blood leukocyte subsets were evaluated in cases and controls. Blood monocytes expressing CD14 and CD44 molecules were increased in patients with endometriosis. Alternatively, B lymphocytes were shown to be significantly decreased in cases compared with controls.

CONCLUSION(S)

Although these results suggest that endometriosis is associated with some systemic manifestations, the exact role of these modulations remains unclear.

Morphological quantitative changes in the number of lymphocytes, macrophages and plasma cells in the uterus and lymph nodes of rats exposed to the systemic administration of BCG

This study was designed to investigate the effect of systemic administration of BCG on the morphological quantitative changes in the number of lymphocytes, macrophages and plasma cells in the uterus and lymph nodes of rats. Thirty female virgin Wistar Albino rats, aging 6 months and weighing between 200-250 g, were assigned to the two experimental groups; BCG treated and controls (n = 15). BCG group received 0.1 ml BCG in tail skin and control group received 0.1 ml saline at the same place. Two weeks after injections, rats in both groups were anesthesized with a high dose of ether and decapitated. Uterus and ileocecal lymph nodes were processed to determine a napthyl acid esterase (ANAE)-positive T lymphocytes and macrophages. The plasma cells were stained with the methyl green-pyronin method. It was found that the numbers of T lymphocytes, macrophages and plasma cells in the uterus and the ileocecal lymph nodes of BCG treated group significantly increased indicating the presence of an immune response to the systemic BCG administration. It was concluded that the systemic administration of BCG increases humoral and cellular immunity in endometrium, myometrium and regional lymph nodes. The immune deficiency system plays an important role in the pathogenesis of endometriosis. Therefore, the endometriosis might be prevented by using periodical administration of BCG. However, further experimental and clinical studies associated with these issue are required.

Use of intraperitoneal interferon alpha-2b therapy after conservative surgery for endometriosis and postoperative medical treatment with depot gonadotropin-releasing hormone analog: a randomized clinical trial

OBJECTIVE

To evaluate the possible therapeutic effects of interferon alpha-2b left in the peritoneum after surgery, followed by or not followed by treatment with GnRH analogs.

DESIGN

A prospective, randomized clinical trial.

SETTING

University hospital.

PATIENT(S)

Fifty-two infertile patients with moderate or severe endometriosis.

INTERVENTION(S)

Laparotomic conservative surgery and either interferon alpha-2b or saline alone left in the pouch of Douglas followed by administration of either GnRH analogs depot or oral indomethacin with transvaginal echography and analysis of CA-125, immunoglobulins, and lymphocyte populations.

MAIN OUTCOME MEASURE(S)

Recurrence of endometriosis was considered clinically, echographically, and laparoscopically.

RESULT(S)

Recurrence of endometriosis in four cases without interferon (15.4%) versus 11 patients (42.3%) with interferon alpha-2b. Life table analysis showed significant differences between the groups with and without interferon 21 months after conservative surgery. There were no differences in the recurrence between the groups with or without GnRH analogs. Likewise, there were no significant changes in immunoglobulins and lymphocyte populations among patients with and without recurrence of endometriosis. The patients that received GnRH analogs depot showed a decrease in the number of CD16 and an increase of CD11b cells after treatment.

CONCLUSION(S)

The use of interferon alpha-2b within the peritoneal cavity after conservative surgery may be inappropriate because it increased later recurrence of endometriosis. The postoperative treatment with GnRH analogs did not significantly reduce the recurrence rate. Immunoglobulins and lymphocyte populations did not change in relation to the recurrence of endometriosis.

Endometriotic haptoglobin binds to peritoneal macrophages and alters their function in women with endometriosis

OBJECTIVE

To evaluate the effects of endometriotic haptoglobin on peritoneal macrophage function.

DESIGN

Prospective laboratory study.

SETTING

School of medicine.

PATIENT(S)

Twenty-three women with and without endometriosis.

INTERVENTION(S)

Peritoneal macrophages cultured without or with haptoglobin.

MAIN OUTCOME MEASURE(S)

Peritoneal macrophage haptoglobin immunoreactivity, adhesion, and interleukin-6 (IL-6) production.

RESULT(S)

In vivo, significantly more peritoneal macrophages from women with endometriosis bound haptoglobin and exhibited reduced adhesion compared to women without endometriosis. In vitro, haptoglobin treatment significantly decreased peritoneal macrophage adherence only in women without endometriosis; this effect was not seen in women with endometriosis, probably owing to in vivo haptoglobin saturation. Conversely, haptoglobin treatment robustly increased IL-6 production only by macrophages from women with endometriosis, suggesting differential immune response in these women.

CONCLUSION(S)

Endometriotic lesions synthesize and secrete a unique form of haptoglobin (endometriosis protein-I) that is up-regulated by IL-6. This study shows that haptoglobin adheres to peritoneal macrophages; decreases adhesion, which may influence phagocytic function; and up-regulates IL-6 production. Hence, a feed-forward loop is proposed whereby endometriotic lesion haptoglobin decreases macrophage phagocytic function while increasing IL-6 production, which in turn increases endometriotic haptoglobin and promotes establishment of endometriosis.

Altered expression of a cell-cycle suppressor gene, Tob-1, in endometriotic cells by cDNA array analyses

OBJECTIVE

Interleukin (IL)-1beta, a product of activated peritoneal macrophages, is a central cytokine coordinating neovascularization and monocyte chemotaxis in endometriotic implants. To evaluate the effects of this cytokine on normal endometrial stromal cells and endometriotic stromal cells we performed cDNA expression array analyses before and after exposure to IL-1beta.

DESIGN

Nested case-control study of women with and without laparoscopic evidence of endometriosis.

SETTING

Reproductive endocrinology clinic at a university hospital.

PATIENT(S)

Endometriosis and normal endometrial biopsies from eight patients were used to prepare stromal cell cultures from which mRNA was extracted.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Commercially available expression arrays (Atlas Human cDNA Expression Array, Clontech, representing 597 individual genes) were used to screen for mRNAs whose expression was affected by 12 hours of exposure to IL-1beta (10 ng/mL). Northern blotting and subsequent quantitative densitometric evaluation was done to confirm steady-state levels of Tob-1 mRNA transcripts.

RESULT(S)

Array analyses revealed a cell-cycle regulatory gene, Tob-1, which was differentially expressed by the two cell types after incubation with IL-1beta. Tob-1 was reduced 48% in endometriotic stromal cells exposed to IL-1beta, but there was only a 16% reduction in normal endometrial stromal cells. Replicate Northern analyses (n = 4) showed that exposure to IL-1beta for 12 hours resulted in a 25% +/- 5% diminution of Tob-1 mRNA in endometriotic stromal cells. In contrast, no significant decrease (<3%) was observed in IL-1beta exposed normal endometrial stromal cells.

CONCLUSION(S)

Tob-1, a cell-cycle inhibitor gene is differentially responsive to IL-1beta in endometriotic stromal cells compared to normal endometrial stromal cells. IL-1beta down-regulated Tob-1 in endometriotic stromal cells, but had no significant effect on normal endometrial stromal cells. Our results suggest that IL-1beta promotes growth of endometriotic lesions through inhibition of Tob-1. These findings are the first to associate IL-1beta with an alteration of cell-cycle gene expression in cells derived from endometriotic implants.

Endometriosis: novel etiopathogenetic concepts and clinical perspectives

OBJECTIVE

To discuss current ideas about therapy for endometriosis derived from new observations generated by using molecular biology techniques and in vivo animal models of disease.

METHOD(S)

The MEDLINE database was reviewed for English-language articles on new drugs that affect the endocrine or immunologic system, the possibility that endometriosis has multiple forms, and the association of endometriosis with cancer. Specific attention was given to in vivo studies in animals or humans.

CONCLUSION(S)

Among the novel potential candidate drugs, aromatase inhibitors and raloxifene should be considered for treatment of postmenopausal women with endometriosis. Notable observations have emerged from studies of immunomodulators and antiinflammatory agents in animal models of disease. These findings must be confirmed in women. The histogenesis of ovarian endometriomas is still unclear, thus limiting new experimental approaches to this form of disease. Given the low but established risk for malignant transformation of endometriosis, efforts should be directed toward identification of susceptibility loci for the disease and its potential transformation into cancer.

Regulation of fas ligand expression by IL-8 in human endometrium

Numerous cytokines and growth factors are synthesized in the endometrium. IL-8 is one of these cytokines regulating endometrial function. It is a neutrophil chemoattractant/ activating factor and a potent angiogenic agent. IL-8 is elevated in the peritoneal fluid of women with endometriosis. We have previously demonstrated a direct proliferative effect of IL-8 on endometrial stromal cells. We hypothesized that increased levels of IL-8 in the endometriotic environment could up- regulate Fas ligand (FasL) expression in endometrial cells and may be relevant for the development of a relative local immunotolerance in endometriosis by inducing apoptosis of cytotoxic T lymphocytes. To test our hypothesis, we studied the in vitro regulation of FasL expression and apoptosis by IL-8 in endometrial cells. Western blot analysis in endometrial stromal, glandular, and Ishikawa cells revealed that IL-8 up- regulated FasL protein expression in these cells. By semiquantitative RT-PCR analysis, IL-8 does not alter the expression of either Fas or FasL mRNA levels in these cells. Immunocytochemistry results from endometrial stromal cells treated with IL-8 demonstrated an up-regulation of FasL protein expression. IL-8 decreased apoptosis rate in endometrial stromal cells as evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay. We observed an increased apoptotic rate in Jurkat (T lymphocyte line) cells plated on endometrial stromal cells previously treated with IL-8. We speculate that increased FasL expression by IL-8 may induce apoptosis of T lymphocytes and thus produce a local immunotolerant environment for the development of ectopic implants.

Extracellular matrix-dependent regulation of Fas ligand expression in human endometrial stromal cells

Interaction between endometrial stromal cells and extracellular matrix (ECM) components has a crucial role in the development of endometriosis. Endometrial stromal cells attach to the mesothelial surface of peritoneum by means of integrins during their initial implantation and growth in endometriosis. Similarly, interaction between integrin and the extracellular matrix is also crucial for the remodeling of the endometrium during early pregnancy. We hypothesized that adhesion of endometrial stromal cells to the extracellular matrix could suppress the immunologic reaction to implanting endometrial cells by inducing the expression of Fas ligand (FasL), a mediator of the apoptotic pathway. Western blot analysis of human endometrial stromal cells plated onto fibronectin, laminin, and collagen IV revealed higher levels of FasL protein expression compared with endometrial stromal cells that plated to BSA-coated plates (control). Immunocytochemistry results from endometrial stromal cells plated to extracellular matrix proteins demonstrated a similar up-regulation of FasL expression. Eutopic endometrial stromal cells from women with endometriosis demonstrated higher FasL expression on control plates and those coated with extracellular matrix proteins compared with those from women without endometriosis. Disruption of actin cytoskeleton in endometrial stromal cells by treatment with cytochalasin D blocked the increase of FasL protein expression that occurred in response to adhesion to the extracellular matrix. These results suggest that attachment of endometrial stromal cells during retrograde menstruation to a new environment such as peritoneum with increased expression of laminin, fibronectin, and collagen IV could lead to an increase in FasL expression. Induction of FasL expression by adhesion of endometrial stromal cells to the extracellular matrix may take part in the development of a relative immunotolerance by inducing apoptosis of cytotoxic T lymphocytes, which will allow further development of ectopic implants.

High omega-3:omega-6 fatty acid ratios in culture medium reduce endometrial-cell survival in combined endometrial gland and stromal cell cultures from women with and without endometriosis

OBJECTIVE

To study the effects of omega-3 and omega-6 polyunsaturated fatty acid (PUFA) on in vitro proliferation of endometrial cells and their production of the cytokine interleukin-8 (IL-8).

DESIGN

In vitro study.

SETTING

Obstetrics and gynecology department, University of Aberdeen.

PATIENT(S)

Women attending an infertility clinic.

INTERVENTION(S)

In vitro cell cultures using culture mediums supplemented with normal and high ratios of omega-3 PUFA and omega-6 PUFA.

MAIN OUTCOME MEASURE(S)

In vitro survival and production of IL-8 by dispersed endometrial cells.

RESULT(S)

In vitro survival of endometrial cells from women with and without endometriosis was significantly reduced in the presence of high omega-3:omega-6 PUFA ratios compared with cells incubated in the absence of fatty acids, in balanced omega-3:omega-6 PUFA ratios, and in high omega-6:omega-3 PUFA ratios. Endometrial cells from women with endometriosis secreted higher concentrations of IL-8, especially in the presence of high omega-3:omega-6 PUFA ratios.

CONCLUSION(S)

omega-3 PUFA may have a suppressive effect on the in vitro survival of endometrial cells and omega-3 PUFA be useful in the management of endometriosis by reducing the inflammatory response and modulating cytokine function.

Apoptosis in endometrial glandular and stromal cells in women with and without endometriosis

BACKGROUND

The aetiology of endometriosis is unknown. Ectopic dissemination of the endometrial cells gives origin to endometriotic lesions, but occurs in women with and without endometriosis. It has been suggested that increased ectopic cell survival facilitates their implantation. The objectives of this study were to evaluate endometrial apoptosis in women with endometriosis according to: (i) cyclic changes, (ii) glandular and stromal contribution, and (iii) stage of the disease.

METHODS

The subjects were women undergoing diagnostic laparoscopy and endometrial biopsies for suspected endometriosis. Spontaneous apoptosis was evaluated using TdT-mediated dUTP-biotin nick end-labelling (TUNEL) assay. Apoptotic cells per 10 mm(2) (apoptotic index) in an area of 10-50 mm(2) in 5 microm endometrial tissue sections were counted and location of these cells was recorded.

RESULTS

The apoptotic index in glandular epithelium was lower in endometriosis than controls (26.0 +/- 5.5 versus 51.2 +/- 9.7, P = 0.03) but not in the stroma (36.3 +/- 6.4 versus 48.4 +/- 11.3, NS). In controls, apoptosis was highest during the late secretory/menstrual and early proliferative phases and cyclic variability was apparent. In endometriosis, this cyclic variability was lost. There was a trend toward decreased apoptosis with increasing stage of the disease, but the differences lacked statistical significance.

CONCLUSIONS

Spontaneous apoptosis is decreased in the endometrial glands in women with endometriosis, especially during late secretory/menstrual and early proliferative phases of the cycle. This may indicate increased viability of endometrial cells shed during menses, facilitating their ectopic survival and implantation.

Induction of endometriosis in the mouse inhibits spleen leukocyte function

BACKGROUND

It is still unclear whether the immunologic perturbation observed in women with endometriosis represents an intrinsic defect of the immune system or it is consequent to the presence of endometrium in ectopic sites. The present study was aimed to evaluate the immunoregulatory properties of ectopic endometrial implants in a model of experimental endometriosis in mice.

METHODS

Endometriosis was induced in n=10 mice by inoculating endometrial fragments obtained from syngenic donor mice into the peritoneal space. Twelve mice were similarly treated but were not inoculated with endometrium and were used as control mice. At an explorative laparotomy performed in all the animals after three weeks, the extent of peritoneal lesions, when present, was evaluated by weight assessment and surface area measurement. In both mice that were inoculated with endometrium and control animals, spleens were removed. The effect of endometriosis induction on concanavalin A-induced spleenocyte proliferation was investigated.

RESULTS

A significant inhibition of spleenocyte growth was demonstrated in mice in which endometriosis was induced (36156+/-3061 cpm) compared to control animals (47172+/-3210 cpm; p<0.05). Moreover, a significant inverse correlation was found between spleenocyte proliferation and weight and surface area of the peritoneal endometriotic lesions (r=0.76; p<0.02 and r=0.75; p<0.02, respectively).

CONCLUSION

These findings suggest that the presence of ectopic endometrial implants within the peritoneal cavity leads to substantial changes of the immune response in vivo. These changes may have significant implications for the understanding of the etiopathogenesis of endometriosis.

Immunobiology of endometriosis

OBJECTIVE

To provide a review of the humoral and cellular immunology of endometriosis and to discuss the rationale for future approaches to diagnosis and treatment.

DESIGN

Literature survey.

RESULT(S)

Defective immunosurveillance in women who are destined to develop endometriosis may allow for the survival of ectopic endometrial tissue. The evidence includes endometrial cell resistance to apoptosis, perhaps through the secretion of proteins that interfere with implant recognition and/or FasL expression by stromal cells, inducing apoptosis of Fas-bearing immune cells. Although the immune response may be defective, aspects of it clearly are enhanced in endometriosis, as is seen by the generalized polyclonal B-cell autoimmune activation and secretion of immune proteins. Several cytokines, chemokines, and growth factors (including vascular growth factors) are increased in women with endometriosis.

CONCLUSION(S)

A complex network of locally produced cytokines modulate the growth and inflammatory behavior of ectopic endometrial implants. Proinflammatory proteins from endometriotic lesions and associated immune cells contribute to the enhanced inflammatory reaction associated with endometriosis that subserves the survival of these lesions instead of leading to their demise.

Peritoneal fluid concentrations of interleukin-11 in women with endometriosis

OBJECTIVE

To determine the peritoneal fluid concentrations of interleukin-11 (IL-11) in women with endometriosis as compared with the control group.

DESIGN

A prospective, controlled study.

SETTING

The obstetrics and gynecology department of a teaching hospital and a university immunology department.

PATIENT(S)

Sixty consecutive women undergoing laparoscopic surgery for benign gynecological indications.

INTERVENTION(S)

Peritoneal fluid was obtained during laparoscopy, and the concentration of IL-11 was measured.

MAIN OUTCOME MEASURE(S)

Concentration of IL-11 in correlation with the presence of endometriosis, its stage, and the phase of the menstrual cycle.

RESULT(S)

IL-11 was detectable in the peritoneal fluid of 64% of women tested. Concentrations of IL-11 showed no correlation with the presence of endometriosis, the American Fertility Society stage of the disease, or the phase of the menstrual cycle.

CONCLUSION(S)

We found no evidence to suggest that IL-11 is involved in the pathogenesis of pelvic endometriosis.

Effect of hormonal agents on monocyte chemotactic protein-1 expression by endometrial epithelial cells of women with endometriosis

OBJECTIVE

To assess whether hormonal agents used in the medical treatment of endometriosis, such as danazol and GnRH agonist, exert direct regulatory action on monocyte chemotactic protein-1 (MCP-1) expression by endometrial epithelial cells.

DESIGN

Primary cultures of epithelial cells isolated from human endometrium were exposed to different concentrations of cytokines and steroid hormone analogs. Expression of MCP-1 was analyzed at the levels of protein and messenger RNA.

SETTING

Gynecology clinic and laboratory of endocrinology of reproduction.

PATIENT(S)

Women presenting for infertility or pelvic pain in whom endometriosis was diagnosed by using laparoscopy.

INTERVENTION(S)

Endometrial tissue biopsy performed at laparoscopy.

MAIN OUTCOME MEASURE(S)

Secretion of MCP-1 protein was measured by using enzyme-linked immunosorbent assay, and mRNA steady-state levels were measured by performing Northern blot analysis.

RESULT(S)

Buserelin acetate, a GnRH agonist (0.1-10 ng/mL), had no significant effect on MCP-1 expression, whereas danazol (10(-7)-10(-5) M), a testosterone analog, and dexamethasone, an anti-inflammatory glucocorticoid hormone (10(-12)-10(-6)M), showed a direct and a dose-dependent inhibitory effect on MCP-1 expression. This effect occurred at the level of protein and mRNA.

CONCLUSION(S)

The findings of the study may affect understanding of the mechanisms by which hormonal treatments act on endometriosis and influence its clinical manifestations.

Gonadotropin-releasing hormone analog repairs reduced endometrial cell apoptosis in endometriosis in vitro

OBJECTIVE

Impaired sensitivity of endometrial tissue to spontaneous apoptosis in women with endometriosis contributes to the abnormal implantation and growth of endometrium at ectopic sites. Our purpose was to examine the effect of gonadotropin-releasing hormone analog, widely used in the treatment of endometriosis, on the reduced rate of endometrial apoptosis in endometriosis.

STUDY DESIGN

Paired ectopic and eutopic endometrial tissue specimens were obtained from 13 patients with endometriosis, and control samples were taken from 8 patients with uterine myoma. Apoptotic cell death was assessed biochemically and morphologically with an enzyme-linked immunoassay and Hoechst No. 33342 staining of deoxyribonucleic acid fragment, respectively.

RESULTS

Spontaneous apoptosis was significantly lower in ectopic and eutopic endometrial tissue from patients with endometriosis (0.22 +/- 0.082 in absorbance) than in endometrial tissue from control subjects (0.52 +/- 0.483)(P < 0.001). Incubation with a gonadotropin-releasing hormone analog (1 micromol/L) increased the apoptotic rate of endometrial cells from patients with endometriosis to 0.56 +/- 0.501 (P <.001). The effect of this gonadotropin-releasing hormone revealed a dose dependency; a half-maximal effect occurred with 10 nmol/L; however, the control endometrium was not affected.

CONCLUSION

Exposure to gonadotropin-releasing hormone results in changes of the sensitivity of endometriotic endometrium to spontaneous apoptosis; these changes in sensitivity may, in turn, release endometrial cells from resistance to apoptosis and result in reduced survival and growth. This phenomenon could, at least in part, account for the therapeutic action of gonadotropin-releasing hormone analog on endometriosis.

Update on the epidemiology of systemic lupus erythematosus: new spins on old ideas

Systemic lupus erythematosus is a serious autoimmune disease of obscure etiology with a propensity for widespread organ involvement. Its manifestations range from ephemeral symptoms to life-threatening events such as thromboses and strokes. Although once considered rare, SLE now appears to be relatively common in certain subsets of the population. Considerable publicity for this disorder as a "silent killer" has heightened public awareness and may have contributed to the increases in the number of individuals reporting this diagnosis in surveys. Epidemiologic studies face numerous challenges in disease classification and case ascertainment. Despite this, such studies have increased in size and number, and have generated novel etiologic hypotheses, ranging from environmental pollutants to viral infections.

Endometrial ability to implant in ectopic sites can be prevented by interleukin-12 in a murine model of endometriosis

Immune dysfunctions in endometriosis are widely documented but the effectiveness of immunotherapies for the management of the disease is still debated. Progress in this field has also been limited by the lack of an appropriate animal model of the disease. In this study, we created a model of endometriosis in immunocompetent mice to verify the ability of endometrium to implant in ectopic sites and to investigate the potential application of the cytokine interleukin (IL)-12 in preventing this ectopic implantation. Endometriotic lesions were induced in both C57BL/6 and BALB/c mice by inoculating syngenic endometrial fragments through a small laparotomic incision into the peritoneal space. All the animals challenged with syngenic endometrium showed evidence of peritoneal endometriosis at 3 weeks. Histologically, endometriotic lesions consisted of cystic endometrial glands surrounded by a stroma. Intraperitoneal injection of IL-12 was able to reduce total weight and total surface area of endometriotic lesions respectively of 77 and 61% in C57BL/6 and of 42 and 28% in BALB/c mice. These results demonstrate that IL-12 is able to induce a significant prevention of ectopic endometrial implantation in an in-vivo model of endometriosis. These findings support the possibility of using the immune system to generate novel therapies for the management of the disease.