The stimulus responsible for the peritoneal fluid inflammation observed in infertile women with endometriosis

High intensity interval training is superior to moderate intensity continuous training in enhancing the anti-inflammatory and apoptotic effect of pentoxifylline in the rat model of endometriosis

This study investigated the effects of pentoxifylline (PTX), high intensity interval training (HIIT) and moderate intensity continuous training (MICT) separately and in combination, on inflammatory and apoptotic pathways in the rat model of induced endometriosis. Endometriosis was induced through surgery on female Sprague-Dawley rats. Six weeks after the first surgery, the second look laparotomy was performed. After induction of endometriosis in rats, they were divided into control, MICT, PTX, MICT+ PTX, HIIT, HIIT+PTX groups. Two weeks after the second look laparotomy, PTX and exercise training interventions were performed for eight weeks. Endometriosis lesions were assessed histologically. Proteins content of the NF-κB, PCNA and Bcl-2 were measured by immunoblotting and genes expression of the TNF-α and VEGF were measured by Real-time PCR methods. Findings of the study indicated that, PTX significantly decreased volume and histological grading of lesions, proteins of NF-κB and Bcl-2; and genes expression of the TNF-α, and VEGF in lesions. HIIT significantly decreased volume and histological grading of lesions, NF-κB, TNF-α and VEGF in lesions. MICT did not induce any significant effect on the study variables. Although, MICT+PTX decreased significantly volume and histological grading of lesions, as well as NF-κB, and Bcl-2 in lesions, however, these factors were not significantly different with the PTX group. HIIT+PTX decreased significantly all of the study variables compared to other interventions, except for VEGF when compared to PTX. In summary, combination of PTX and HIIT can induce enhancing effect on suppression of endometriosis through suppressing inflammation, angiogenesis, and proliferation and enhancing apoptosis.

Regulation of Inflammatory and Proliferative Pathways by Fotemustine and Dexamethasone in Endometriosis

Endometriosis is a common disease. Its pathogenesis still remains uncertain, but it is clear that cell proliferation, apoptosis and chronic inflammation play an important role in its development. This paper aimed to investigate the anti-proliferative and anti-inflammatory effects of a combined therapy with fotemustine and dexamethasone. Endometriosis was induced by intraperitoneal injections of uterine fragments from donor animals to recipient animals. Next, the pathology was allowed to develop for 7 days. On the seventh day, fotemustine was administered once and dexamethasone was administered daily for the next 7 days. On Day 14, the animals were sacrificed, and peritoneal fluids and lesions were explanted. In order to evaluate the gastrointestinal side effects of the drugs, stomachs were harvested as well. The combined therapy of fotemustine and dexamethasone reduced the proinflammatory mediator levels in the peritoneal fluid and reduced the lesions’ area and diameter. In particular, fotemustine and dexamethasone administration reduced the heterogeneous development of endometrial stroma and glands (histological analysis of lesions) and hyperproliferation of endometriotic cells (immunohistochemical analysis of Ki67 and Western blot analysis of PCNA) through the mitogen-activated protein kinase (MAPK) signaling pathway. Combined fotemustine and dexamethasone therapy showed anti-inflammatory effects by inducing the synthesis of anti-inflammatory mediators at the transcriptional and post-transcriptional levels (Western blot analysis of NFκB, COX-2 and PGE2 expression). Fotemustine and dexamethasone administration had anti-apoptotic activity, restoring the impaired mechanism (TUNEL assay and Western blot analysis of Bax and Bcl-2). Moreover, no gastric disfunction was detected (histological analysis of stomachs). Thus, our data showed that the combined therapy of fotemustine and dexamethasone reduced endometriosis-induced inflammation, hyperproliferation and apoptosis resistance.

Diagnosis and treatment of tubal diverticula: report of 13 cases

Tubal diverticula is a rare disease, and the literature includes only a few reports of this condition. We tentatively summarized 13 cases to investigate the clinical characteristics, diagnosis, and treatment of tubal diverticula. The clinical manifestations, diagnosis at hysterosalpingography (HSG), surgical treatment, and pregnancy rates of the 13 cases were retrospectively analyzed. Tubal diverticula is more prevalent in women with endometriosis than in infertile patients (6.7% vs 2.1%; p = .000). Eleven patients (84.6%) had endometriosis, which was in an early stage (I or II) in 9 patients (81.8%). HSG may reveal accumulation of radiopaque contrast medium around the distal end of the tubes, suggesting the presence of diverticula. All 13 cases were diagnosed via laparoscopy, and the diverticula were resected during surgery. Eleven of the 13 patients (84.6%) had ≥2 subtle tubal abnormalities. The pregnancy rate in 9 of the 11 patients with tubal diverticula was 81.8%, with 1 ectopic pregnancy (11.1%) and 1 spontaneous abortion (12.5%). HSG may be helpful in enabling the diagnosis of tubal diverticula. It is important that tubal diverticula be diagnosed via laparoscopy with use of diluted methylene blue dye and careful evaluation.

Combination of non-invasive and semi-invasive tests for diagnosis of minimal to mild endometriosis

OBJECTIVES

Non-surgical diagnostic approach for endometriosis would be of great gain to both physicians and patients. The aim of this study was to evaluate the diagnostic value of serum measurement of IL-6 combined with the presence of nerve fibres in the functional layer of endometrium for diagnosis of minimal-mild endometriosis.

METHODS

In this prospective study 114 women who underwent laparoscopy for infertility and/or pelvic pain were divided into two groups: control cases (40 cases) with no pathologic findings; and endometriosis patients (74 cases) [subdivided into stages 1-2 or minimal-mild (MM) and stages 3-4 or moderate-severe cases]. Blood was drawn one day before laparoscopy and stored for subsequent analysis of IL-6. Endometrial biopsy was obtained prior to laparoscopy and Immunohistochemistry was performed using the pan-neuronal marker protein gene product 9.5(PGP9.5). Then laparoscopic diagnosis of endometriosis confirmed by histopathology was done.

RESULTS

Serum IL-6 with a threshold of 15.4 pg/ml was found to be able to diagnose MM endometriosis with 89.5 % sensitivity and 82.5 % specificity, but sensitivity and specificity of presence of nerve fibres in the functional layer of endometrium were 92 % and 80 % respectively. When two diagnostic modalities were combined the sensitivity and specificity were raised to 100 and 92.5 % respectively.

CONCLUSIONS

Combination of both serum IL-6 and presence of nerve fibres in the endometrium is more reliable method for diagnosis of MM endometriosis than in single test.

Intraperitoneal inflammation decreases endometriosis in a mouse model

BACKGROUND

The role of the immune system in the pathogenesis of endometriosis remains elusive. It has been shown that patients have an altered peritoneal environment with increased levels of inflammatory cytokines, activated macrophages and reduced clearance of retrogradely transported endometrial fragments. However, it is not known if this unique inflammatory situation is cause or consequence of endometriosis. This study investigates the impact of a pre-existing peritoneal inflammation on endometriosis establishment in a mouse model.

METHODS

Endometriosis was induced by intraperitoneal injection of enhanced green fluorescent protein (EGFP)-expressing endometrium in mice. In parallel, a peritonitis model was established via intraperitoneal injection of thioglycolate medium (TM). Finally, endometriosis was induced in the inflamed peritoneal cavity and lesion establishment as well as morphological and histological characteristics were analysed.

RESULTS

Induction of endometriosis in an inflamed peritoneal cavity resulted in fewer lesions and significantly lower sum of lesion surface area per mouse in the TM-treated group. Additionally, a higher amount of non-attached debris could be detected in the peritoneal cavity of TM-treated mice.

CONCLUSIONS

An intraperitoneal inflammation decreases endometriosis establishment in this mouse model. Thus, a pre-existing peritoneal inflammation might not be a factor favouring the development of endometriosis.

Imbalance in the peritoneal levels of interleukin 1 and its decoy inhibitory receptor type II in endometriosis women with infertility and pelvic pain

OBJECTIVE

To evaluate the levels of interleukin-1beta (IL1beta) and its inhibitory soluble interleukin-1 receptor type II (IL1R2) in the peritoneal fluid (PF) of normal women and patients with endometriosis suffering from pelvic pain and infertility.

DESIGN

Retrospective study using ELISA to measure peritoneal fluid IL1beta and soluble IL1R2.

SETTING

Gynecology clinic and human reproduction research laboratory.

PATIENT(S)

Sixty-eight normal women and 154 women with endometriosis.

INTERVENTION(S)

Peritoneal fluid samples were obtained at laparoscopy.

MAIN OUTCOME MEASURE(S)

IL1beta and soluble IL1R2 concentrations in the PF samples.

RESULT(S)

This study showed a marked decrease in peritoneal soluble IL1R2 levels in women with endometriosis compared to normal women and a concomitant increase in the levels of IL1beta. Both fertile and infertile women with endometriosis had lower soluble IL1R2 and higher IL1beta concentrations than fertile women having a normal gynecological status, but the difference was more significant in infertile endometriosis patients. Compared with normal controls, the decrease in soluble IL1R2 levels was less significant in women with endometriosis than without pelvic pain, whereas the increase in IL1beta concentrations was statistically significant only in women with endometriosis reporting pelvic pain.

CONCLUSION(S)

This study revealed an imbalance between IL1beta and its decoy inhibitory receptor type 2 in women with endometriosis, which was particularly obvious in those who were infertile, and suggests that a defect in the local control of IL1 may be involved in the pathophysiology of endometriosis and related infertility.

Serum interleukin-6 levels are elevated in women with minimal-mild endometriosis

BACKGROUND

There is a need for a reliable marker of endometriosis, especially in early stages of peritoneal disease during which imaging is not effective. The use of serum interleukin (IL)-6 as a marker is controversial. To readdress the matter, patients undergoing laparoscopy were prospectively evaluated for serum IL-6 levels.

MATERIALS AND METHODS

A total of 119 women 31 years old who underwent laparoscopy were divided into groups: control patients (n = 38) with no pathologic findings; endometriosis sufferers (n = 47) with minimal-mild (MM, n = 11) or moderate-severe (MS, n = 36) endometriosis; uterine myomas (n = 13) and benign ovarian pathologies (n = 21). Blood was drawn on cycles days 5-12 and stored for subsequent analysis of IL-6 and carbohydrate antigen (CA)-125 levels.

RESULTS

Serum IL-6 levels were significantly (P = 0.002) higher in women with MM endometriosis (29.4 9.0 pg/ml) than in controls (15.7 9.3 pg/ml). When all the non-endometriosis patients were grouped together (n = 72) and serum IL-6 (17.8 12.1 pg/ml) compared with MS (n = 36; 17.6 10.3 pg/ml) and MM (n = 11; 29.4 9.0 pg/ml) endometriosis significantly (P < 0.01) higher levels in MM endometriosis were observed as compared to the other two groups. Serum Ca-125 levels were significantly (P < 0.01) elevated in MS endometriosis. A serum IL-6 threshold of 25.75 pg/ml afforded a sensitivity of 75% and specificity of 83% in the diagnosis of MM endometriosis. Sensitivity and specificity for CA-125 in the diagnosis of MS endometriosis, using 35 IU/ml as the cut-off value, were 47% and 97%, respectively.

CONCLUSIONS

IL-6 is a reliable non-invasive marker of MM endometriosis, whereas Ca-125 is of use as a marker of severe cases.

The reproductive significance of human Fallopian tube cilia

Effective tubal transport of ova, sperm and embryos is a prerequisite for successful spontaneous pregnancy. Although there is much yet to be discovered about the mechanisms involved, it is evident that tubal transit is a far more complicated process than initially thought. Propulsion of gametes and embryos is achieved by complex interaction between muscle contractions, ciliary activity and the flow of tubal secretions. Evidence is accumulating of the important and possibly pre-eminent role of ciliary motion in this process; and this review describes current knowledge about ciliary activity and its physiological regulation. There is also a description of the effects on ciliary function of cigarette smoking and various pathological states, including endometriosis and microbial infection, with consideration given as to how altered ciliary activity may impact upon fertility.

Effects of peritoneal fluid from endometriosis patients on the release of vascular endothelial growth factor by neutrophils and monocytes

BACKGROUND

An increase in the level of the vascular endothelial growth factor (VEGF) production has been reported in the peritoneal fluid (PF) of endometriosis patients. This suggests that changes in the vascular permeability and angiogenesis play an important role in the pathophysiology of this disease. This study examined the effects of the PF obtained from endometriosis patients on the release of VEGF by neutrophils and monocytes.

METHODS

Neutrophils and monocytes were obtained from young healthy volunteers and cultured with the PF obtained from either endometriosis patients (EPF) (n=18) or a control group (CPF) (n=4). A human monocyte/macrophage cell line, THP-1, was cultured with either 10% EPF or 10% CPF. The PF and culture supernatants were assayed for VEGF using ELISA. Real-time PCR and Western blotting were used to measure the VEGF mRNA and protein expression level, respectively.

RESULTS

The VEGF levels were higher in the EPF than in the CPF (591+/-75 versus 185+/-31 pg/ml, P<0.05). However, the level of VEGF released by THP-1 cells in CPF and EPF was similar. The EPF induced the release of VEGF by neutrophils, but no VEGF was released by monocytes. The VEGF mRNA expression levels in the neutrophils were higher in the EPF, which was abrogated by cycloheximide, suggesting that the EPF induces the production of VEGF in neutrophils. Neutralizing antibodies against IL-8 and TNF-alpha did not completely prevent the EPF-induced release of VEGF by the neutrophils, even though these growth factors stimulated the release of VEGF by neutrophils. There was a positive correlation between the VEGF and IL-10 concentrations in the EPF (correlation coefficient=0.549, P=0.012, n=18), but the neutralizing antibody of IL-10 did not affect the release of VEGF by the EPF-treated neutrophils.

CONCLUSION

The EPF induced the production and release of VEGF by neutrophils, suggesting that neutrophils may be a source of peritoneal VEGF. In addition, neutrophil-derived VEGF might be a marker for diagnosing endometriosis.

Tumor necrosis factor alpha secretion by peritoneal macrophages in patients with endometriosis

INTRODUCTION

As a cytotoxic product of activated monocytes, macrophages, and lymphocytes, tumor necrosis factor alpha (TNF-alpha)--together with other cytokines and growth factors--is an important component in the immune response of the human organism. In addition, TNF-alpha plays a central role in neoangiogenesis. Because of its cytotoxicity with regard to several tumor cells and its motility-hindering effect on human sperm, TNF-alpha is considered to be a significant pelvic mediator of female sterility.

OBJECTIVE

The goal of our study was to determine as to whether or not an increased TNF-alpha secretion by peritoneal macrophages (PM) can be measured in female patients with endometriosis compared with healthy subjects, and if TNF-alpha secretion can be correlated with the activity of endometriosis.

METHODS

During infertility work-up, 100 female patients underwent a diagnostic laparoscopy. In accordance with the rAFS classification as well as from the macroscopic aspect of the degree of activity of the endometriosis, the patients were divided as follows: an endometriosis-free control group with a completely normal pelvic status (n=35) and three groups with increasing stages of endometriosis (n=65). In the control group (Group 1), the TNF-alpha concentrations (median values with minimum / maximum) were 6.2 pg/ml (1.9/10.2), in Group 2 with rAFS stage I/II less active endometriosis 56.33 pg/ml (39.5/71.2), in Group 3 with rAFS stage I/II but highly active endometriosis 81.41 pg/ml (68.4/98.7), while in Group 4 with rAFS stage III/IV 200,15 pg/ml (182.6/226.8), respectively.

CONCLUSION

In conclusion, we were able to show that the TNF-alpha secretion of PM was significantly higher in patients with proven endometriosis compared to the control group. These results were found to be statistically significant and were in accordance with the histological findings. Thus, due to its immunomodulating potential, TNF-alpha may be a marker of both activity and stage 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.

Soluble interleukin-1 receptor type II blocks monocyte chemotactic protein-1 secretion by U937 cells in response to peripheral blood serum of women with endometriosis

OBJECTIVE

To assess the ability of peripheral blood serum from women with endometriosis to induce monocyte chemotactic protein-1 (MCP-1) secretion by monocytes and the putative role of the interleukin-1 (IL-1) system in endometriosis-associated monocyte activation.

DESIGN

Cultures of U937 monocytic cells exposed to serum from normal women (control group) or women with endometriosis.

SETTING

Gynecology clinic and human reproduction research laboratory.

PATIENT(S)

Seventy-nine women with endometriosis and 38 control women with no evidence of endometriosis at laparoscopy.

INTERVENTION(S)

Peripheral blood obtained a few days before laparoscopy.

MAIN OUTCOME MEASURE(S)

MCP-1 secretion in the culture medium and serum concentrations of soluble IL-1 receptor type II (sIL-1RII), IL-1beta, and IL-1alpha by ELISA or by enzyme immunometric assay.

RESULT(S)

Serum concentrations of sIL-1RII were significantly lower in women with stage I-II endometriosis than in control women, whereas serum concentrations of IL-1beta and IL-1alpha were comparable between the two groups. The serum of women with endometriosis induced higher secretion of MCP-1 by U937 cells than that of control women, particularly in the initial stages of endometriosis (stages I-II), and recombinant IL-1RII (rIL-1RII) significantly blocked that secretion.

CONCLUSION(S)

These findings point toward a deficiency in the mechanisms involved in the down-regulation of IL-1 actions at the systemic level and reveal sIL-1RII as a key factor involved in that process.

Marked elevation of macrophage migration inhibitory factor in the peritoneal fluid of women with endometriosis

OBJECTIVE

To evaluate the presence of macrophage migration inhibitory factor (MIF) in the peritoneal fluid of normal fertile women and patients with endometriosis and its growth-promoting activity toward human endothelial cells.

DESIGN

Retrospective study using ELISA to measure peritoneal fluid MIF, and [3H]-thymidine incorporation into the DNA of human endothelial cells to assess its mitogenic activity.

SETTING

Gynecology clinic and human reproduction research laboratory.

PATIENT(S)

Thirty-six healthy women and 57 women with endometriosis.

INTERVENTION(S)

Peritoneal fluid samples were obtained at laparoscopy.

MAIN OUTCOME MEASURE(S)

Macrophage migration inhibitory factor concentrations in the peritoneal fluid samples and [3H]-thymidine incorporation into the DNA of human microvascular endothelial cells to assess proliferation.

RESULT(S)

This study demonstrated the presence of MIF in the peritoneal fluid and a 238% increase of MIF levels in women with endometriosis as compared with healthy women. Both fertile and infertile women with endometriosis had significantly higher MIF concentrations than did fertile women with normal gynecological status, but the difference was more significant in infertile endometriosis patients. Anti-MIF antibody significantly inhibited proliferation of human microvascular endothelial cells in response to peritoneal fluids from healthy women and women with endometriosis stages I-II and III-IV, as assessed by [3H]-thymidine incorporation.

CONCLUSION(S)

This study revealed the presence of MIF in the peritoneal fluid and its increased levels in endometriosis and suggests that MIF may be involved in endometriosis-associated infertility and angiogenesis.

Spontaneous and stimulated secretion of monocyte chemotactic protein-1 and macrophage migration inhibitory factor by peritoneal macrophages in women with and without endometriosis

OBJECTIVE

To assess spontaneous and stimulated secretion of monocyte chemotactic protein-1 (MCP-1) and macrophage migration inhibitory factor (MIF) by peritoneal macrophages in women with and without endometriosis.

DESIGN

Macrophages were isolated from the peritoneal fluid and cultured for different periods of time (6, 20, and 44 hours) without any stimulation to determine spontaneous secretion of MCP-1 and MIF. Macrophages were also exposed to 1 microg/mL lipopolysaccharide for 6 hours to evaluate the stimulated secretion of these cytokines.

SETTING

Gynecology clinic and human reproduction research laboratory.

PATIENT(S)

Twelve fertile women and 11 women with endometriosis.

INTERVENTION(S)

Peritoneal fluid obtained at laparoscopy.

MAIN OUTCOME MEASURE(S)

Monocyte chemotactic protein-1 and MIF concentrations in the culture medium using ELISA.

RESULT(S)

Peritoneal macrophages of women with endometriosis demonstrated an increased capacity to secrete MCP-1 either spontaneously or after stimulation with lipopolysaccharide. They also showed a marked tendency for an increased secretion of MIF, but no statistically significant difference was found.

CONCLUSION(S)

Monocyte chemotactic protein-1 and MIF production by peritoneal macrophages may contribute to paracrine and autocrine activation and to macrophage accumulation in the peritoneal cavity of women with endometriosis. These mechanisms may exacerbate peritoneal inflammation and favor the growth of endometrial implants.

Abnormal interleukin-1 receptor type II gene expression in the endometrium of women with endometriosis

Interleukin 1 (IL-1) is a major proinflammatory cytokine that is believed to play a central role in the pathophysiology of endometriosis. The IL-1 receptor type II (IL-1RII) is known to bind to IL-1 and to inhibit its biological effects. In our previous studies, we showed that human endometrium expresses IL-1RII, and we observed reduced expression of the protein in women with endometriosis. The aim of this study was to investigate IL-1RII mRNA in the endometrial tissue of normal women (n = 26) and of patients with various degrees of endometriosis (n = 53). In situ hybridization showed that IL-1RII mRNA expression was significantly decreased in endometriosis, particularly during the early stages of the disease (stages I and II). This was quite obvious in both glandular and stromal cells, and it was corroborated by reverse transcription-polymerase chain reaction analysis of IL-1RII mRNA in the endometrial tissue of women with (n = 10) and without (n = 8) endometriosis. The reduced levels of IL-1RII mRNA in the endometrium of women suffering from endometriosis reveals a profound defect in IL-1RII gene expression and, consequently, a reduced capability of endometrial tissue to down-regulate IL-1 activity. Defective IL-1RII gene expression during the early stages of endometriosis (stages I and II) may contribute to the etiology of the disease.

Transvaginal hydrolaparoscopy but not standard laparoscopy reveals subtle endometriotic adhesions of the ovary

OBJECTIVE

To determine whether transvaginal hydrolaparoscopy is superior to standard laparoscopy for detection of subtle endometriotic adhesions of the ovary.

DESIGN

Videotapes of standard laparoscopy and transvaginal hydrolaparoscopy were viewed by an independent observer in random order and in a blinded manner.

SETTING

Tertiary referral centers for infertility.

PATIENT(S)

Patients with minimal or mild endometriosis (n = 11) and unexplained infertility (n = 10) on standard laparoscopy from a group of 43 patients with infertility who were undergoing both studies.

INTERVENTION(S)

Transvaginal hydrolaparoscopy followed by standard laparoscopy.

MAIN OUTCOME MEASURE(S)

Detection of unexplained ovarian adhesions.

RESULT(S)

Patients with minimal and mild endometriosis and unexplained infertility had significantly more ovarian adhesions on transvaginal hydrolaparoscopy than on standard laparoscopy. The subtle adhesions seen on transvaginal hydrolaparoscopy but not on standard laparoscopy were filmy, microvascularized, and nonconnecting.

CONCLUSION(S)

Unexplained ovarian adhesions are frequently detected on transvaginal hydrolaparoscopy but not on standard laparoscopy in infertile patients with minimal and mild endometriosis and unexplained infertility.

Decreased expression of the decoy interleukin-1 receptor type II in human endometriosis

Many of the biological changes occurring in the endometrium during the menstrual cycle bear a striking resemblance to those associated with inflammatory and reparative processes. Hence, it would not be surprising to find that cytokines known for their pro-inflammatory properties, such as interleukin-1 (IL-1), could play a key role in the physiology of this tissue and that their action would be tightly controlled by local mechanisms. In the present study, immunohistochemical and Western blot analyses show that in normal women (n = 39), the endometrial tissue expresses, in a cycle-dependent manner, the IL-1 receptor type II (IL-1RII), a molecule of which the only biological property known to date is that of capturing IL-1, inhibiting thereby its binding to the functional type I IL-1 receptor. IL-RII immunostaining was particularly intense within the lumen of the glands and at the apical side of surface epithelium. Interestingly, the intensity of staining was markedly less pronounced in the endometrium of women with endometriosis (n = 54), a disease believed to arise from the abnormal development of endometrial tissue outside the uterus, especially in the early stages of the disease (stages I and II). This study is the first to show the local expression in endometrial tissue of IL-1RII, a potent and specific down-regulator of IL-1 action and its decreased expression in women suffering from endometriosis.

Tumour necrosis factor alpha concentrations in the peritoneal fluid of infertile women with minimal or mild endometriosis are lower in patients with red lesions only than in patients without red lesions

Tumour necrosis factor alpha (TNFalpha) of peritoneal fluid is believed to have important pro-inflammatory and angiogenic activities in the complex mechanisms of development of peritoneal endometriotic lesions. We have evaluated the concentrations of TNFalpha and macrophages in peritoneal fluid of infertile women with minimal or mild endometriosis and related them to the presence of peritoneal red lesions alone (red lesions only group; n = 11) or their absence (non-red lesions group; n = 36). A group of 39 infertile normo-ovulatory patients with normal pelvic anatomy was used as controls. TNFalpha concentrations did not differ between controls and either group of patients. Patients with red lesions only had significantly lower concentrations of TNFalpha in peritoneal fluid (P < 0.05) and had a higher proportion of samples with undetectable concentrations (P < 0.05) than patients without red lesions. The significant difference in TNFalpha concentrations was present when comparing the groups of patients in the proliferative phase but not in the secretory phase. Macrophage concentrations were not different in the groups. Our findings are compatible with an impairment of macrophage function and therefore lend support to the theory that an inappropriate immunological response of the peritoneal environment to regurgitated endometrium may play a part in the initial phases of endometriotic implants.

"The Flemish Giant", reflections on the defense against endometriosis, inspired by Professor Emeritus Ivo A. Brosens

Reproductive research benefits from combining animal and clinical studies. In Leuven, rabbits have constituted an animal model for many reproductive disorders, especially for those that involved surgical treatment. Much of what has been learned from animal experiments has been applied to human clinical reproductive research soon after. In this manuscript we wish to address the problem of the constant intra-abdominal battle between the menstrual aggressor and the peritoneal defense. From all published evidence we may conclude that endometriosis appears to be a dynamic disease, especially in the early phase, with subtle, atypical lesions emerging and vanishing again. In the end however the peritoneal defense system will prevail and the disease will be contained in the majority of patients. When doing repeat laparoscopies in young patients one should be prepared to encounter more advanced histological types of lesions, which not necessarily do have to indicate more advanced stages of the disease: the classical, blue and black powderburn spots and blueberry lesions reflect the extinguishing phase of the dynamic endometriotic process, and herald its inactivated histological end-stage. The dynamic phase of the disease may involve a varying interval of each patient's life, and medical suppression of the activity of the implants during this interval may lead one to conclude erroneously that treatment has been effective. If subsequently (after the end of medical suppression of the activity of the lesions) ovarian activity resumes and the lesions are stimulated again by ovarian steroids, their productive activity returns. Recurrence of disease may be diagnosed if at that stage a laparoscopy would be performed, whereas in reality only reactivation of temporarily obscured lesions did occur. The suppressed, dormant (but never absent) lesions produce mucus again, desquamation occurs, and reaction by the surrounding tissue. The inflammatory response, the local hyperemia and the neogenesis of vessels accentuate the presence of previously invisible endometriosis lesions and make them visible again. Endometriosis resumes its temporarily halted natural course of development, tissue remodeling occurs again, the battle between the aggressor and the defense resumes and waxing and waning of the several types of lesions, red, white and black, can be found again.

Transferrin receptor (CD71) expression in peritoneal macrophages from fertile and infertile women with and without endometriosis

PROBLEM

Hyperactivated macrophages are implicated in the pathophysiology of endometriosis-associated infertility. This study investigates transferrin receptor expression (CD71) as a marker of hyperactivity in peritoneal macrophages of infertile patients with minimal to mild endometriosis (group 1, n = 25).

METHOD OF STUDY

Expression of the activation antigen CD71 on peritoneal fluid macrophages was determined by a specific monoclonal anti-CD71 antibody using indirect immunofluorescence technique and was analyzed by flow cytometry. Three different control groups of women were used: women with unexplained infertility (group 2, n = 25), fertile women with endometriosis (group 3, n = 10), and fertile women without endometriosis (group 4, n = 25).

RESULTS

The percentage of CD71 positive cells was significantly increased in infertile women with endometriosis as compared with the three control groups. There were no differences among groups 2, 3, and 4 with respect to the percentage of CD71 positive macrophages.

CONCLUSIONS

Our results favor the concept that hyperactivated macrophages play a role in the pathophysiology of endometriosis-associated subfertility, a feature which is lacking in patients with unexplained infertility.

Peritoneal cellular immunity and endometriosis

PROBLEM

An immunologic basis has long been considered to be very important in the pathogenesis of endometriosis. Interactions of the peritoneal cells, which comprise macrophages, B cells, T cells, natural killer (NK) cells, and retrograde endometrial cells, are critical, but remain controversial, for exploring the pathogenesis of endometriosis.

METHOD OF STUDY

Accumulated data from the literature were reviewed, and our data were analyzed.

RESULTS

The data show that peritoneal macrophages are activated by the recurrent reflux of menstrual shedding. Humoral and local endometrial autoantibodies are detected in patients with endometriosis, but B cells are not quantitatively increased. There is decreased NK cell activity in the peritoneal cavity and peripheral blood, and this decreased activity may be related to the failure to clear out the ectopic endometrial tissue. Peritoneal T cells are predominant by Th1 inflammatory cells, and these cells are impaired because of a decrease in activation (especially HLA-DR+CD4+CD3+ population) and in the production of interleukin-2. Inflammatory cytokines such as interleukin-1, interleukin-6, and tumor necrosis factor-alpha are elevated in the peritoneal fluid of women with endometriosis.

CONCLUSIONS

The peritoneal NK and T lymphocytes are suppressed in women with endometriosis, but whether these immunologic deviations are the cause or the result of endometriosis is still unclear. Further studies are required to determine what role immunologic factors play in the pathophysiology of endometriosis.

Pathogenesis of endometriosis

This article reviews the pathogenesis of endometriosis, which involves retrograde dissemination of endometrium and/or development in situ by metaplasia, and there is evidence suggesting that genetic and hormonal factors may play a role. There is also substantial evidence that immunologic factors, namely peritoneal macrophages, T cells, natural killer cells, and soluble products secreted by these cells, are involved in the pathogenesis of endometriosis.

Correlation of basal menses CA-125 levels and 6 month pregnancy rates in women undergoing treatments for infertility without assisted reproductive methods

PROBLEM

The objective of this study was to evaluate the correlation of menstrual CA-125 levels with pregnancy rates (PRs) after 6 months of treatment for infertility.

METHOD

The sample consisted of a heterogenous group of 160 women who sought treatment for infertility. Treatments include progesterone supplementation, donor insemination, intrauterine insemination, and ovulation induction therapy. No laparoscopies were done during the study period. A baseline CA-125 level was drawn during menses before the initiation of therapy. Patients were followed for 6 months of treatment or until a pregnancy was achieved.

RESULTS

There was no difference in the 6 month PR or viable PR by CA-125 level.

CONCLUSIONS

Elevated CA-125 levels are not predictive of poor fertility potential at least during the first 6 months of infertility therapy. Even though these higher levels sometimes suggest that endometriosis is present, the data suggest that correction of male factor, cervical factor or ovulation factor provides effective PRs without the need for laparoscopic intervention.

Increased monocyte chemotactic protein-1 level and activity in the peripheral blood of women with endometriosis. Le Groupe d'Investigation en Gynécologie

OBJECTIVE

Our purpose was to evaluate monocyte chemotactic protein-1 in the peripheral blood of women with and without endometriosis.

STUDY DESIGN

Fifty-seven patients with endometriosis at laparoscopy done for infertility and pelvic pain were compared with 44 fertile women with no evidence of endometriosis at tubal ligation by laparoscopy. Monocyte chemotactic protein-1 concentration in the plasma was determined by enzyme-linked immunosorbent assay and its biologic activity was evaluated by measuring monocyte chemotaxis with use of a human histiocytic cell line (U937).

RESULTS

Monocyte chemotactic protein-1 concentrations (median and range of values) found in the plasma were higher in patients with endometriosis (163, 0 to 788 pg/ml) than in normal controls (0, 0 to 355 pg/ml). This elevation was significant only in the minimal stage of endometriosis (revised American Fertility Society stage I). However, increased chemotactic activity (mean number of migrating cells/mm2 +/- SEM) was found in the stages I (1240 +/- 141), II (519 +/- 30), and III-IV (523 +/- 23) of the disease compared with normal controls (205 +/- 20). A total of 35% to 44% of this activity was inhibited in the presence of an antibody specific to monocyte chemotactic protein-1.

CONCLUSION

Endometriosis is associated with increased level and activity of monocyte chemotactic protein-1 in the peripheral blood. The elevation and activation of this cytokine could play a relevant role in the immunoinflammatory process associated with the disease.

Cytokine-induced secretion of monocyte chemotactic protein-1 by human endometriotic cells in culture. The Groupe d'Investigation en Gynécologie

OBJECTIVE

Local secretion of chemotactic factors could contribute to the attraction of macrophages into the peritoneal cavity of women with endometriosis. The purpose of this study was to investigate the ability of endometriotic cells to produce monocyte chemotactic and activating protein-1 in response to interleukin-1 beta and tumor necrosis factor-alpha, which are found in elevated levels in the peritoneal fluid of patients with endometriosis.

STUDY DESIGN

Cultures of fibroblast-like and epithelial cells isolated from endometriotic tissue were incubated with different concentrations of cytokines for varying periods of time. The de novo secretion of monocyte chemotactic protein-1 in the culture supernatants was analyzed by immunoprecipitation and electrophoresis after metabolic labeling with sulfur 35-labeled cysteine.

RESULTS

The incubation of endometriotic fibroblast-like cells with interleukin-1 beta and tumor necrosis factor-alpha resulted in a time- and dose-dependent release of monocyte chemotactic protein-1 into the culture supernatant. Coincubation of the cells with tumor necrosis factor-alpha and interferon gamma resulted in a synergistic and dose-dependent increase of the monocyte chemotactic protein-1 secretion, whereas interferon gamma alone had no significant effect. Preliminary results indicate that monocyte chemotactic protein-1 is also produced by endometriotic epithelial cells in response to the same cytokines.

CONCLUSIONS

Cytokine-stimulated endometriotic cells synthesize and secrete monocyte chemotactic protein-1 in culture, and they may play a relevant role in the recruitment of macrophages to the peritoneal cavity of patients by the local production of chemotactic factors.

Menstruation as the pelvic aggressor

Cumulative evidence supports the concept of retrograde menstruation being a pelvic aggressor as it contributes to both the development of endometriosis and related symptoms such as dysmenorrhoea and infertility. A major problem in studying the association between these entities (retrograde menstruation, endometriosis, dysmenorrhoea and infertility) is the lack of an accurate method to quantify the amount of retrograde menstruation.

Endometriosis-associated infertility

Despite intense clinical interest and increasingly sophisticated diagnostic techniques, we know surprisingly little of the relationship between endometriosis and infertility or the mechanism of infertility in these couples. No therapy specifically directed toward the ectopic endometrial implants, medical or surgical, has been demonstrated to improve the likelihood of pregnancy for couples with endometriosis-associated infertility. This is consistent with the observation that, in the absence of mechanical distortion of the pelvic viscera, no therapy directed against the implants improves the likelihood of pregnancy in these couples. The reason for this lack of progress is most probably that the mechanism of infertility in these couples remains to be determined. At present, it would be more accurate to say that these couples have unexplained infertility. The most promising therapeutic approach is to treat women with endometriosis-associated infertility with a non-specific cycle fecundity enhancing technique. Typically this is one of the newer assisted reproductive technologies such as controlled ovarian hyperstimulation with intrauterine insemination of capacitated sperm. Since the fecundity of many of the women with endometriosis in the later reproductive years is rapidly declining, this may represent their most cost-effective option for establishing a pregnancy. Only with further effort directed towards determining the mechanisms of infertility in these couples will a more effective therapy be forthcoming.