Peritoneal fluid environment and infertility

Immune micro-environment analysis and drug screening for ovarian endometriosis

BACKGROUND

Patients of ovary endometriosis have an abnormal immune micro-environment, leading to endometrial tissue that from retrograde menstruation evade immune surveillance and subsequently develop into ectopic lesions.

OBJECTIVE

This study aims to elucidate the crucial immune cells and molecular pathways that are associated with an aberrant immune micro-environment of endometriosis.

METHOD

In this study, we identified differentially expressed genes between ovarian ectopic endometrial tissue (OVE) and eutopic endometrial tissue from patients with endometriosis (PE) and non-endometriosis patients (CON) by analyzing the mRNA sequencing data. Additionally, we used WGCNA(Weighted Gene Co-expression Network Analysis) to screen for key genes related to immune cell infiltration and compared the sub-types of infiltrating immune cells using CIBERSORT(cell-type identification by estimating relative subsets of RNA transcript). Subsequently, we conducted a single-cell analysis on the identified key genes. Furthermore, we analyzed potential drugs suitable for ovarian endometriosis treatment using pRRophertic.

RESULTS

Seven key genes associated with immune cell infiltration were screened out. The expression of these genes in OVE was significantly lower than that in PE and CON. These key genes were mainly enriched in the NK cell-mediated cytotoxicity pathway, especially for CD16 + CD56dim NK. Moreover, NK cells infiltration in ovarian endometriosis was significantly reduced compared with PE and CON, while M2 macrophage shown the opposite. Results of the single-cell analysis showed that the expression of the seven key genes in NK cells and monocyte-macrophages in OVE was significantly lower than that in PE or CON. Additionally, we identified potential drugs suitable for ovarian endometriosis treatment.

CONCLUSION

The decreased infiltration of NK cells and increased infiltration of M2 macrophages contribute to the evasion of immune surveillance against endometrial tissue, promoting the progression of OVE. Therefore, potential strategies for the treatment of OVE include increasing NK cell activation and decreasing M2 macrophage polarization.

Unique Sensitivity of Uterine Tissue and the Immune System for Endometriotic Lesion Formation

Endometriosis is a debilitating disease that affects about 10% of reproductive-aged adolescents and women. The etiology of the disease is unknown; however, a prevailing hypothesis is that endometriosis develops from retrograde menstruation, where endometrial tissue and fluids flow back through the oviducts into the peritoneal cavity. There is no cure for endometriosis, and symptoms are treated palliatively. Despite the advances in knowledge, the complexity of endometriosis etiology is still unknown. Recent work by our group suggests that the initiation of endometriosis is immune-dependent. Using a mouse model of endometriosis, we hypothesized the initiation of endometriosis is immune regulated and uterine endometrium specific. In the absence of a functional immune system non-obese diabetic/severe combined immunodeficiency (NOD/SCID mice), endometriotic lesions did not form. Uterine endometrial tissue forms endometriotic lesions, whereas tissues with differing basal expression levels of estrogen receptor alpha (ESR1) and estrogen receptor beta (ESR2), similar cellular composition to uterus (i.e. bladder, mammary gland, and lung), and treated with estradiol did not form lesions. As MMP7 is known to play a major role in the organization/reorganization of the endometrium during the menstrual cycle, blocking metalloproteinase (MMP) activity significantly decreased the invasive properties of these cells. Together, these findings suggest that endometriosis is immune and uterine specific and that MMP7 likely plays a role in the ability of uterine tissue and the innate immune system to establish and maintain endometriotic lesions.

Alterations of CD4+T Cell Subsets in Blood and Peritoneal Fluid in Different Stages of Endometriosis

Background

Endometriosis is a chronic inflammatory disorder with known immune disturbances. The aim of this study was to compare the frequency of different CD4+ T cells [T helper (Th)1, Th2, Th17 and regulatory T cells (Tregs)] in peripheral blood (PB) and peritoneal fluid (PF) of patients that have early and advanced stages of endome- triosis with a control group.

Materials and Methods

In this case control study, PB and PF samples were collected from women aged 24-40 years who underwent laparoscopy procedures. The frequency of CD4+ T subsets were analysed by flow cytometry and com- pared between three study groups; early endometriosis (stage I, II), advanced endometriosis (stage III, IV) and control (no endometriosis). T cell numbers were compared between the PB and PF in each of the aforementioned groups.

Results

No statistically significant difference was found between the study groups regarding the numbers of Th1, Th2 and Th17 cells in PB. The PF of patients with advanced endometriosis had increased numbers of Th17 cells compared to the control group (P=0.003), with P values of 0.059 and 0.045 in both menstrual phases. Increased numbers of Th2 cells in PF from early compared to advanced stages of endometriosis were detected exclusively in the luteal phase (P=0.035). The control group had increased numbers of Treg and Th2 cells in the PF compared to PB (both, P value=0.046). However, in the early stages of endometriosis there were more Th2, Th17 and Treg cells in the PF compared to PB (P values: 0.005, 0.047 and 0.013, respectively), while the number of Th17 cells was higher in the PF compared with PB in the advanced stages of endometriosis (P= 0.013).

Conclusion

There were increased numbers of Th17 cells in the PF of patients with advanced stages of endometriosis, which could be related to the severity of this disease.

Circular RNA as a potential diagnostic and/or therapeutic target for endometriosis

Endometriosis is a pathology form of endometrium that behaves in a similar way to malignancies, such as invasion and resistance to apoptosis. Circular RNAs (CircRNAs) are a class of noncoding RNAs that have several biological functions including, miRNA sponging, sequestering of proteins, enhancing parental gene expression and translation resulting in polypeptides. In this review, we highlighted the roles of circRNAs as potential diagnostic and therapeutic biomarkers in endometriosis. Moreover, we summarized the roles of circRNAs in the pathogenesis of endometriosis via different signaling pathways, such as the miRNA network and apoptosis.

Use of a Mouse Model of Experimentally Induced Endometriosis to Evaluate and Compare the Effects of Bisphenol A and Bisphenol AF Exposure

BACKGROUND

Endometriosis is a gynecological disease affecting 1 in 10 women of reproductive age. Endometriosis incidence has risen; however, whether this rise is due to disease awareness or environmental contamination is not known.

OBJECTIVE

The objective of this study was to determine if bisphenol A (BPA) or bisphenol AF (BPAF) potentiate the development of endometriosis and if hormonal status alters how toxicant exposure affects disease.

METHODS

A mouse model of endometriosis, where minced uterine tissue is injected into the peritoneal cavity of a host mouse, was used to examine the effects of BPA and BPAF on endometriosis lesion development in ovariectomized and hormonally intact mice. BPA and BPAF were delivered through diet to include no-observed-adverse-effect-level (NOAEL) and the low-observed-adverse-effect-level (LOAEL) exposure levels. After six weeks (at necropsy), lesions, ovaries, and blood were collected to examine characteristics, gene expression, and hormonal regulation.

RESULTS

BPA and BPAF treatments affected endometriosis in a manner specific to dose and hormonal status of the host mouse. Estrogen and endometriosis-mediated differences in lesion target gene expression also depended on hormonal status. In intact mice, ovarian steroidogenic pathways were disrupted, progesterone levels were lowered, and atretic oocyte numbers were higher with toxicant exposure. BPAF, more so than BPA, resulted in more endometriosis lesion growth, but both toxicants disrupted normal ovarian signaling.

CONCLUSION

These findings further our understanding of the effects and hormonal impacts of BPA and BPAF on endometriosis perturbation in ovariectomized and hormonally intact mice. BPAF appeared to be similar if not more estrogenic than BPA and may be affecting an environmental contribution of the increased incidence of endometriosis. https://doi.org/10.1289/EHP3802.

Endometriosis: where are we and where are we going?

Endometriosis currently affects ~5.5 million reproductive-aged women in the U.S. with symptoms such as painful periods (dysmenorrhea), chronic pelvic pain, pain with intercourse (dyspareunia), and infertility. It is defined as the presence of endometrial tissue outside the uterine cavity and is found predominately attached to sites within the peritoneal cavity. Diagnosis for endometriosis is solely made through surgery as no consistent biomarkers for disease diagnosis exist. There is no cure for endometriosis and treatments only target symptoms and not the underlying mechanism(s) of disease. The nature of individual predisposing factors or inherent defects in the endometrium, immune system, and/or peritoneal cavity of women with endometriosis remains unclear. The literature over the last 5 years (2010-2015) has advanced our critical knowledge related to hormones, hormone receptors, immune dysregulation, hormonal treatments, and the transformation of endometriosis to ovarian cancer. In this review, we cover the aforementioned topics with the goal of providing the reader an overview and related references for further study to highlight the progress made in endometriosis research, while concluding with critical areas of endometriosis research that are urgently needed.

Chitotriosidase levels in patients with severe endometriosis

OBJECTIVE

To study the levels of chitotriosidase activity in the peritoneal fluid and the plasma of patients with severe endometriosis and control subjects.

MATERIALS AND METHODS

Twenty-five women with laparoscopically and histopathologically confirmed endometriosis (study group) and 27 control patients who had undergone laparoscopic surgery were included. Peritoneal fluid and peripheral blood were obtained from all the patients before the surgery. Chitotriosidase activities were measured.

RESULTS

Analysis of chitotriosidase activity in the peritoneal fluid of patients with endometriosis showed that there was no significant difference between endometriosis and control group, respectively (32.04 ± 64.20 vs. 15.25 ± 31.17 nmol/mL/h; p > 0.05). Analysis of chitotriosidase activity in plasma of patients with endometriosis showed significantly increased levels of chitotriosidase levels compared with the control group (74.81 ± 60.54 vs. 14.10 ± 26.17; p < 0.001), respectively.

CONCLUSION

We found that the activity of chitotriosidase in plasma was statistically higher in severe endometriosis patients than women without endometriosis.

Effect of peritoneal fluid from patients with minimal/mild endometriosis on progesterone release by human granulosa-lutein cells obtained from infertile patients without endometriosis: a pilot study

OBJECTIVE

To evaluate the effect of peritoneal fluid (PF) from women without and with minimal/mild endometriosis on progesterone (P) release by cultured human granulosa-lutein cells obtained from infertile patients without endometriosis submitted to ovarian hyperstimulation for in vitro fertilization (IVF).

STUDY DESIGN

A pilot study was performed. Human granulosa-lutein cells, obtained from 11 infertile patients without endometriosis (tubal or male factors of infertility) submitted to ovarian hyperstimulation for IVF, were cultured without PF (basal production) and with increasing volumes of steroid-extracted PF samples from 11 patients with endometriosis and 11 patients without endometriosis. Progesterone (P) levels in the media after 72 h culture were measured by chemoluminescence assay. The non-parametric Mann-Whitney-test was used for statistical analysis.

RESULTS

PF from patients without endometriosis stimulated P release in a dose-dependent manner up to the dose of 100 microl/ml (10% concentration) when compared with basal production (without adding PF). P release was similar in cultures stimulated with PF from patients with or without endometriosis at 1% (10 microl/ml) and 5% (50 microl/ml) concentrations. At 10% concentration, there was a non-statistically significant reduction in progesterone release by granulosa cells stimulated with PF from patients with endometriosis. PF from patients with endometriosis significantly reduced P release at 30% concentration (300 microl/ml).

CONCLUSIONS

PF stimulates P release by human granulosa-lutein cells in a dose-dependent manner. However, higher concentrations of PF from patients with minimal/mild endometriosis reduce P release, suggesting it contains factors that may compromise ovarian steroidogenesis.

Effect of ovarian involvement on peritoneal fluid cytokine concentrations in endometriosis patients

Peritoneal fluid cytokines are important for initiation and progression of endometriosis. The objective of this study was to compare a group of five cytokines (interleukins IL-1 beta, IL-6, IL-8, IL-13 and tumour necrosis factor alpha; TNFalpha) in peritoneal fluid of endometriosis patients with ovarian involvement (Group I, n = 17) to those in patients without ovarian involvement (Group II, n = 33) and to a reference group without endometriosis (Group III, n = 25). All three groups were comparable regarding age, parity and body mass index. IL-8 concentrations were significantly higher in groups I and II compared with the reference group (P = 0.01 and 0.02, respectively). Similarly, TNFalpha concentrations were significantly higher in groups I and II compared with the reference group (P < 0.0001 and 0.0004, respectively). All other cytokines were comparable in the three groups. No significant differences were found between groups I and II with respect to the cytokines measured. In conclusion, peritoneal fluid IL-8 and TNFalpha concentrations are significantly higher in endometriosis. Ovarian involvement does not alter the pattern of cytokines. It appears that the inflammatory mediators of endometriosis are similar with and without ovarian involvement.

Decreased lactoferrin levels in peritoneal fluid of women with minimal endometriosis

OBJECTIVE

The aim of the study was to evaluate for the presence of lactoferrin (LTF) in peritoneal fluid (PF) of women with and without endometriosis.

PATIENTS

Seventy-eight women were studied, including 49 women with endometriosis and, as a reference group, 29 patients with functional follicle ovarian cysts.

RESULTS

Lactoferrin levels were detectable in all peritoneal fluid samples. Women with minimal endometriosis had lower PF lactoferrin concentrations compared to both patients with high revised American Fertility Society classification scores and women with follicle ovarian cysts. No significant difference in the peritoneal LTF levels was found between patients with stage II endometriosis, stage III or IV endometriotic disease and women with functional cysts of ovaries.

CONCLUSIONS

Owing to its antibacterial properties lactoferrin is probably an important defense factor in the peritoneal cavity, however its role in the pathogenesis of endometriosis remains enigmatic.

Comparative concentrations of steroid hormones and proteins in human peri-ovulatory peritoneal and follicular fluids

Despite the fact that both peritoneal (PF) and follicular (FF) fluids have a common ovarian origin, FF is a natural inducer of sperm acrosome reaction (AR) while PF is not. To better understand these effects, concentrations of oestradiol, progesterone and proteins in peri-ovulatory PF and FF were determined and compared. PF was aspirated by laparoscopy at the peri-ovulatory stage from women with unexplained infertility. FF was collected from patients undergoing IVF and pooled. PF and FF were tested for the presence of antisperm antibodies. Oestradiol and progesterone were measured by enzyme immunoassay, and total protein concentration was determined and analysed. The AR was determined in spermatozoa that were exposed to PF alone, progesterone-supplemented PF, progesterone, control medium, or ethanol. No antisperm antibodies were found in any fluid tested. Oestradiol and progesterone and concentrations in PF were significantly lower than in FF. Protein concentration was also significantly lower in PF than in FF, but no differences were observed between the electrophoretic patterns. When capacitated spermatozoa were exposed to progesterone-supplemented PF there was a significant increase in the percentage of AR with respect to those in PF, control medium or ethanol. These results suggest that the lack of AR-stimulating activity of PF was related to its lower progesterone concentration compared with FF.

Laboratory testing for endometriosis

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

Decreased levels of interleukin-18 in peritoneal fluid but not in serum of patients with endometriosis

OBJECTIVE

To determine the concentrations of interleukin-18 (IL-18) in peritoneal fluid and serum in patients with endometriosis in comparison with the control group.

DESIGN

A prospective analytical study.

SETTING

The obstetrics and gynecology department of an academic training hospital.

PATIENT(S)

Forty-four patients who underwent laparoscopic surgery for benign gynecologic diseases.

INTERVENTION(S)

Specimens of peripheral blood and peritoneal fluid were obtained before and during laparoscopic procedures, and the levels of IL-18 were analyzed.

MAIN OUTCOME MEASURE(S)

The concentrations of IL-18 in peritoneal fluid and serum were correlated with the presence of endometriosis, disease stage, and the phase of the menstrual cycle.

RESULT(S)

Interleukin-18 was detectable in 98% of the peritoneal specimens and 84% of the serum specimens of the patients tested. Peritoneal fluid IL-18 concentrations were statistically significantly lower in patients with endometriosis than in patients without endometriosis; the difference in serum IL-18 levels showed no statistically significant difference between the patients with and without endometriosis. The concentrations of IL-18 in peritoneal fluid and serum were not correlated with the stage of endometriosis or the phase of the menstrual cycle.

CONCLUSION(S)

Our results suggest that the decreased levels of IL-18 in peritoneal fluid in patients with endometriosis as compared with the control group may play an important role in the pathogenesis of this disease.

Modulation of human sperm function by peritoneal fluid

OBJECTIVE

To examine the effect of peritoneal fluid on various parameters of sperm function in vitro.

DESIGN

Prospective study.

SETTING

Basic research laboratory.

PATIENT(S)

Semen samples were obtained from normozoospermic volunteers (n = 43). Peritoneal fluids were aspirated laparoscopically from women with unexplained infertility (n = 14). Follicular fluid and oocytes were collected from patients undergoing IVF-ET.

INTERVENTION(S)

Sperm incubated under capacitating conditions were exposed to peritoneal fluid, and functional variables were evaluated in vitro.

MAIN OUTCOME MEASURE(S)

Sperm viability and motility, follicular fluid and calcium ionophore-induced acrosome reactions, protein tyrosine phosphorylation, expression of D-mannose binding sites, and ability of sperm to interact with zona pellucida.

RESULT(S)

Exposure of sperm to peritoneal fluid for up to 6 hours did not affect sperm viability or motility. Unlike follicular fluid, peritoneal fluid did not induce the acrosome reaction. Moreover, incubation of sperm with > or =20% v/v peritoneal fluid for 1 hour prevented the follicular fluid and the ionophore-induced acrosome reaction. Although treatment with peritoneal fluid allowed protein tyrosine phosphorylation during capacitation, it resulted in a significant decrease in the expression of D-mannose binding sites and sperm-zona pellucida binding.

CONCLUSION(S)

Peritoneal fluid maintains sperm survival and decreases sperm ability to respond to inducers of the acrosome reaction and bind to the zona pellucida in vitro, indicating that this fluid might modulate sperm function in vivo.

Investigation of glutathione concentrations in peritoneal fluid from women with and without endometriosis

Changes in the peritoneal fluid (PF) environment have been implicated in the pathogenesis of endometriosis as well as in the decrease of fertility.

OBJECTIVE

To evaluate the concentration of glutathione in PF of women with endometriosis.

PATIENTS

Twenty-one patients with endometriosis (I or II rAFS stage, n=11; III or IV rAFS stage, n=10), and 29 patients with follicular or dermoid ovarian cysts (n=17 and n=12, respectively).

RESULTS

Mean (+/-S.D.) PF glutathione concentration was 0.22+/-0.01 micromol/ml in patients with minimal or mild endometriosis, 0.21+/-0.05 micromol/ml in women with III or IV stage of the disease, 0.24 +/- 0.03 micromol/ml in women with follicle ovarian cysts, and 0.23+/-0.05 micromol/ml in patients with dermoid tumors of ovaries. No significant difference in the peritoneal glutathione level was found between the groups.

CONCLUSION

These results suggest that PF glutathione is not involved in the progression 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.

Role of cytokines in endometriosis

OBJECTIVE

To review the literature on the role of cytokines in the pathogenesis of endometriosis and endometriosis-associated infertility.

DESIGN

Pertinent studies were identified by a computer search of MEDLINE. References of selected articles were hand-searched for additional citations.

RESULT(S)

Recent studies suggest that the peritoneal fluid of women with endometriosis contains an increased number of activated macrophages that secrete various local products, such as growth factors and cytokines. Levels of several cytokines were reported to be elevated in the peritoneal fluid of women with endometriosis. Because the peritoneal environment may be controlled by locally regulated factors, cytokines are believed to play a role in the development and progression of endometriosis and endometriosis-associated infertility. A possible pathogenic mechanism links cytokines with endometriosis.

CONCLUSION(S)

Cytokines, which are produced by many cell types including endometriotic tissues, play diverse roles in the pathogenesis of endometriosis and endometriosis-associated infertility. More studies about the specific role of these cells and soluble factors are needed to improve understanding of endometriosis and to develop novel therapies.

Vascular endothelial growth factor and interleukin-6 in peritoneal fluid of women with endometriosis

OBJECTIVE(S)

To determine [1] vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) levels in peritoneal fluid from women with endometriosis and compare them with those from oral contraceptive (OC) users and normal cycling women and [2] any correlation between VEGF and IL-6 concentrations.

DESIGN

Controlled clinical study.

SETTING

University medical center.

PATIENT(S)

Patients undergoing laparoscopy for infertility or other benign gynecologic conditions.

INTERVENTION(S)

Peritoneal fluid samples were collected.

MAIN OUTCOME MEASURE(S)

Levels of VEGF and IL-6 in peritoneal fluid were determined.

RESULT(S)

Compared with normal controls or women with less severe endometriosis (implant scores of 5 or less), women with more advanced endometriosis (implant scores of 6 or more) have elevated VEGF and IL-6 levels in peritoneal fluid. Compared with normal controls, markedly suppressed IL-6 but similar VEGF levels were found in peritoneal fluid from OC users. Neither VEGF nor IL-6 varied cyclically in normal women or those with endometriosis. There was no correlation between levels of VEGF and IL-6 in peritoneal fluid. There was no correlation between implant scores and VEGF or IL-6 levels.

CONCLUSION

The inflammation associated with endometriosis, through increased levels of peritoneal fluid VEGF, may promote angiogenesis for the progressive growth of endometriosis. Effective treatment of endometriosis by combination estrogen-progestin pills may involve the suppression of such inflammatory responses.

Fibrinolysis in the peritoneal fluid during adhesions, endometriosis and ongoing pelvic inflammatory disease

The concentrations of the specific activators (u-PA and t-PA) and the specific inhibitors (PAI-1 and PAI-2) of the fibrinolytic system were analyzed in the peritoneal fluid in women suffering from intra-abdominal adhesions, endometriosis or pelvic inflammatory diseases (PID). Peritoneal fluids were collected from ten women in whom a laparotomy was performed and an additional 108 in whom a laparoscopy was carried out. In comparison with the normal control patients all activators and inhibitors were significantly increased in cases of PID and when a second-look laparoscopy was performed one week after laparotomy with adhesiolysis. At laparoscopies, when adhesions were verified, u-PA in the peritoneal fluid was significantly increased and in cases of endometriosis PAI-2 was significantly reduced. The start of a laparotomy in order to remove adhesions, initiates a process, resulting in a significant increase of PAI-2 antigen in the pelvic fluid. The results imply that the fibrinolytic system is comprehensively activated in the peritoneal cavity during ongoing inflammatory reaction, and after adhesiolysis. The increase in plasminogen activators in the peritoneal fluid in established cases of pelvic adhesions or endometriosis may indicate that the fibrinolytic system is continuously active to inhibit the further formation of adhesions.

Classification of endometriosis

The evolution of classification schemes for endometriosis has continued since the 1920s, when initial attempts were made to describe endometriosis. The cause, pathophysiology, and natural history of endometriosis remain difficult to characterize. As knowledge about endometriosis increases, classification schemes will change to incorporate new ideas. Evolution of the current American Fertility Society's revised classification of endometriosis is reviewed, as well as evaluation of its use with respect to prediction of fertility and management of pelvic pain. Possible directions for classification in the future are also discussed in this article.

Basic research in endometriosis

A more thorough understanding of the mechanisms associated with the cause and pathophysiology of endometriosis may help in the development of new diagnostic and therapeutic methods for the management of endometriosis. Research has begun to enhance our understanding of endometriosis by demonstrating the differences and similarites between eutopic and ectopic endometrium, and by characterizing the peritoneal environment. Animal models have been developed and validated to conduct studies that are ethically impossible in women. Recently, cell culture models, using purified populations of cells from endometriotic lesions, have provided an appropriate in vitro endometriosis model to study the language by which cells communicate; to evaluate the biochemical effects of steroids, growth factors, pharmacological agents and immunomodulatory agents on the cells; and to study the effects of endometriosis on reproduction.

Effect of peritoneal fluid from patients with mild and severe endometriosis on endometrial stromal cell proliferation

The aim of this study was to evaluate and compare the mitogenic effect of peritoneal fluid (PF) from women with mild and severe endometriosis on the endometrial stromal cell proliferation. Increasing concentrations of PF from women with and without mild or severe endometriosis were added to primary endometrial stromal cell cultures and 3H-thymidine incorporation was used to assess DNA synthesis in these cultures. PF from women with mild endometriosis induced a statistically significant dose-dependent increase in stromal cell thymidine uptake ranged from 5.8 to 14.5 fold, whereas PF from women with severe endometriosis produced an average 51% inhibition of stromal cell proliferation of compared with cells exposed to non-endometriosis PF or exposed to nutrient medium supplemented with 2.5% calf serum alone. PF samples from patients with stage I endometriosis induced a statistically dose-dependent increase in stromal cell proliferation, whereas PF from patients with stage IV endometriosis caused a significant inhibition.

Proliferative activity of the endometrium throughout the menstrual cycle in infertile women with and without endometriosis

OBJECTIVE

To assess whether changes in endometrial proliferation in patients with endometriosis contribute to ectopic endometrial implantation.

DESIGN

Endometrial biopsies from patients with endometriosis were stained immunohistochemically and compared with endometrium of a control group (n = 111). The newly developed monoclonal antibody Ki-S3 was used as a marker of cellular proliferation in surface and glandular epithelia and in stromal cells.

SETTING

Female Infertility Clinic, Research Centre of Obstetrics, Gynecology, and Perinatology, Moscow, Russia, and Institute of Pathology, Christian-Albrechts-University, Kiel, Germany.

PATIENTS

One hundred thirty-nine women with endometriosis and 111 women without endometriosis, all being infertile.

INTERVENTION

Collecting endometrial samples during diagnostic and therapeutic laparoscopy.

MAIN OUTCOME MEASURE

Number of proliferating cells in endometrial stroma, glandular, and surface epithelia.

RESULTS

Endometrial proliferation showed a characteristic cyclic dependency with greatest activity in the follicular phase. Although epithelial proliferation ceased completely during the luteal phase, the number of proliferating cells in the stroma increased again toward the end of the menstrual cycle after its maximum at ovulation. No significant differences could be found between both investigated groups.

CONCLUSIONS

Endometriosis is not due to an altered proliferative activity in eutopic endometrium. Proliferating stromal cells at the end of the menstrual cycle may reflect increasing numbers of immunocompetent cells. Endometrium of patients with endometriosis reveals almost the same cyclical changes as endometrium of patients without endometriosis does. Further attention to cells and cell-mediated reactions in the extrauterine milieu is required to elucidate the pathogenesis of endometriosis.

PGE2 and PGF2 alpha release by human peritoneal macrophages in endometriosis

OBJECTIVE

To test for differences in the amount and activity of peritoneal macrophages present in the peritoneal fluid of women with, and without endometriosis using prostaglandin release by macrophages in culture as a marker.

PATIENTS

Women of reproductive age undergoing laparoscopy for infertility or chronic pelvic pain with postoperative diagnosis of endometriosis and women undergoing laparoscopy for sterilization.

METHODS

Peritoneal fluid was aspirated during laparascopy, volume was recorded, macrophages were isolated via a Ficoll Paque gradient and kept in primary culture. PGE2 and PGF2 alpha release of the cells were measured before and after stimulation with zymosan.

RESULTS

Women with endometriosis had significantly more peritoneal macrophages than controls. Peritoneal macrophages of women with endometriosis released significantly more PGE2 than those of the control group: 8.4 +/- 2.0 versus 1.4 +/- 0.4 ng/ml/10(6) cells (mean +/- SEM, p = 0.0005) and PGF2 alpha: 10 +/- 4.3 (endometriosis) versus 1.8 +/- 0.4 (control) ng/ml/10(6) cells (mean +/- SEM, p = 0.045).

CONCLUSION

There is a significant increase in the amount of prostaglandins released by peritoneal macrophages from women with endometriosis. These prostaglandins might alter uterine and tubal contractility, thereby affecting fertility.

Human intraperitoneal fibrinolytic response to elective surgery

Intra-abdominal adhesions develop in over 90 per cent of patients undergoing laparotomy. Peritoneal fibrinolysis is believed to be important in the pathophysiology of adhesion formation. This study investigated the fibrinolytic response of postoperative peritoneal fluid in 12 patients undergoing elective laparotomy. There was a significant reduction in the plasminogen activating activity to undetectable levels at 24 h, which was sustained at 48 h (P < 0.05). While there was an early reduction in the concentration of tissue plasminogen activator (median 40.0, 28.2, 16.3 and 31.9 ng/ml at 2, 6, 24 and 48 h respectively; P < 0.05), the abolition of functional fibrinolytic activity appeared to be secondary to a marked increase in the concentration of plasminogen activator inhibitor (PAI) 1 (median 86, 196, 800 and 730 ng/ml at 2, 6, 24 and 48 h respectively; P < 0.05) and PAI-2 (median less than 6, 12, 155 and 245 ng/ml at 2, 6, 24 and 48 h respectively; P < 0.05). This reduction in the plasminogen activating activity of peritoneal fluid may favour the formation of permanent fibrous adhesions following surgery.

Endometriosis and infertility: the role of exogenous lipid peroxides in the peritoneal fluid

OBJECTIVE

To determine if lipid peroxides were raised in the pelvic peritoneal fluid of patients with endometriosis.

DESIGN

Control study involving patients with and without endometriosis.

METHODS

The lipid peroxide (malondialdehyde) levels in the pelvic PF of 12 patients with moderate-to severe endometriosis, 15 patients with minimal-mild endometriosis and 13 patients with normal pelvises were compared.

RESULTS

The level of lipid peroxides were not affected by the presence nor the severity of endometriosis.

CONCLUSION

Accelerated lipid peroxidation does not appear to play a role in the causal relationship between endometriosis and infertility.

Hyaluronan and myeloperoxidase in human peritoneal fluid during genital inflammation

The changes in concentration of hyaluronan (HYA) and myeloperoxidase in peritoneal fluid (PF) were studied during genital intraperitoneal inflammation. PF were collected from 111 women undergoing laparatomy for adhesiolysis and reconstructive surgery of the fallopian tubes, or laparoscopy in search of causes of infertility or low abdominal pain. When the number of leukocytes in the PF had been counted, the fluid samples were centrifuged and the supernatants analyzed for the concentrations of HYA and of myeloperoxidase. During genital inflammation, whether post-operative or postinfectious, leukocytosis and elevated levels of HYA and myeloperoxidase were found in the PF. Concentrations of these substances in the PF may be usable as clinical markers for genital inflammation.

Hyaluronan and myeloperoxidase in human peritoneal fluid during genital inflammation

The changes in concentration of hyaluronan (HYA) and myeloperoxidase in the peritoneal fluid (PF) were studied during genital intraperitoneal inflammation. PF were collected from 111 women undergoing laparotomy for adhesiolysis and reconstructive surgery of the fallopian tubes or laparoscopy in search of causes of infertility or low abdominal pain. When the number of leukocytes in the PF had been counted, the fluid samples were centrifuged and the supernatants analyzed for the concentrations of HYA and myeloperoxidase. During genital inflammation, whether postoperative or postinfectious, leukocytosis and elevated levels of HYA and myeloperoxidase were found in the PF. Concentrations of these substances in the PF may be usable as clinical markers for genital inflammation.

Cytokines in the peritoneal fluid of patients with endometriosis

OBJECTIVE

To determine which of the various cytokines interleukin-5 (IL-5), interleukin-6 (IL-6) and interleukin-1 (IL-1) are important in endometriosis.

METHODS

Peritoneal fluid (PF) samples were taken from 55 women at the time of either laparotomy or laparoscopy, and were examined for the levels of IL-5, IL-6 and IL-1 using each cytokine specific sandwich enzyme-linked immunosorbent assay. Thirty-two patients had pelvic endometriosis, eight post-pelvic inflammatory disease, four advanced cancer, three adenomyosis, three benign ovarian tumor, and other diseases. Statistical analysis was performed with the Mann Whitney test, chi-square test or Fisher's test.

RESULTS

Both IL-5 and IL-6 levels in PF specimens with endometriosis tended to be higher than normal, while the same specimens were mostly interleukin-1 beta (IL-1 beta) negative. Of great interest was the negative correlation between log (IL-5) and IL-6 (Fisher's test, P < 0.04).

CONCLUSION

These findings support the concept that IL-5 and IL-6 but not IL-1 are associated with endometriosis.

Influence of peritoneal fluid from spontaneous and stimulated cycles on sperm motility in vitro

Peritoneal fluids (PFs) from spontaneous (n = 14) and gonadotrophin-stimulated cycles (n = 20) were obtained during diagnostic laparoscopy and gamete intrafallopian transfer (GIFT) procedures, respectively. The effects of these fluids on the linear component of sperm motility and on the percentage of motile spermatozoa were studied in vitro by objective motility assessments and compared to a control medium (B2-Ménézo). Overall, the two types of PFs were found to have rather similar effects on the motility parameters studied. However, the fluids from hormonally-stimulated cycles sustained motility better (i.e., sperm velocity and percentage of motile sperm) and in a rather constant manner as a function of time (narrower range distributions of the motility measurements). Furthermore, it was observed that under identical experimental conditions motility measurements depended not only on the type of PF used but also on the sperm sample. These results suggest that assisted reproduction procedures in which PF is the medium where the gametes eventually meet and interact, such as direct peritoneal insemination (DIPI) or peritoneal oocyte and sperm transfer (POST), could have different success rates if performed in spontaneous rather than in stimulated cycles. At the same time, our results may help to explain why different pregnancy rates were reported in different studies using DIP or POST.

Detection of free peritoneal fluid by transvaginal sonography

The recognition of peritoneal fluid is of considerable clinical importance; however, the sensitivity of modern techniques for the detection of this finding has not been determined. The purpose of this study was to assess the utility of transvaginal sonography for the detection of free peritoneal fluid. Nineteen infertile women scheduled to undergo diagnostic laparoscopy were scanned with a 5-MHz transvaginal probe just before the surgical procedure. Peritoneal fluid was then aspirated laparoscopically, and the volume and location was compared to the sonographic findings. The volume of fluid obtained at laparoscopy ranged from 0 mL to 45 mL (median 8 mL). All patients with fluid volumes > or = 0.8 mL had free fluid identified sonographically. The location of fluid observed sonographically corresponded to that noted at laparoscopy in all cases. Free peritoneal fluid was visualized in 8 (73%) of 11 patients with regular menstrual cycles who were in the follicular phase at the time of the study. We conclude that transvaginal sonography is a sensitive and reliable method for the detection of free peritoneal fluid in anatomically normal women. This finding should not necessarily be considered abnormal, at least in women of reproductive age, nor should it be considered diagnostic of oocyte release.

IL6 and acute phase plasma proteins in peritoneal fluid of women with endometriosis

Several authors have documented signs of chronic inflammation in the pelvis of women with endometriosis. We investigated the possible involvement of interleukin 6 (IL6), an important regulator of inflammation and immunity, in minimal and mild endometriosis by measuring levels of IL6 and proteins (alpha 1-acid glycoprotein, alpha 1-antitrypsin, alpha 2-HS glycoprotein and albumin) the synthesis of which is regulated by IL6, in peritoneal fluid (PF) from infertile women with histologically confirmed endometriosis (stage I and II; n = 28) and from endometriosis-free fertile (n = 14) and infertile women (n = 13). Spontaneous and LPS-induced IL6 secretion by cultured PF macrophages from women with endometriosis (n = 12) and without endometriosis (n = 9) were also studied. No significant differences were observed in the concentrations of the four proteins studied. Immunoreactive IL6 was detected in all three groups, with no significant differences. In contrast, significantly higher levels of IL6 were released by both unstimulated (P = 0.01) and LPS-stimulated (P = 0.006) peritoneal macrophages from the women with endometriosis. We conclude that local IL6 synthesis by activated macrophages may play a role in the endometriosis process.

Luteinized unruptured follicle in the early stages of endometriosis as a cause of unexplained infertility

OBJECTIVE

We attempted to clarify the relationship between luteinized unruptured follicle, which occurs in the early stages of endometriosis, and unexplained infertility.

STUDY DESIGN

Seventy patients who had unexplained infertility were reviewed.

RESULTS

Laparoscopic examination showed that 47 patients (67%) had endometriosis; of these, 40 (85%) had minimal or mild disease. The incidence of luteinized unruptured follicle was higher (p < 0.05) in patients who had endometriosis (35%/patient and 25%/cycle) compared with patients who did not have endometriosis (11%/patient and 7%/cycle). Degenerated oocyte cumuli were collected in 6 (43%) of 14 luteinized unruptured follicles diagnosed by transvaginal ultrasound.

CONCLUSIONS

These results show that luteinized unruptured follicle is common in patients who have mild or minimal endometriosis and that it may be one of the causes of endometriosis-associated infertility. Transvaginal ultrasound-guided follicular puncture of luteinized unruptured follicle during the mid luteal phase may be useful in establishing a definitive diagnosis of luteinized unruptured follicle.

Effect of volumetric mixtures of peritoneal and follicular fluid from the same woman on sperm motility and acrosomal reactivity in vitro

OBJECTIVE

To study the effect of peritoneal (PF) and follicular fluids (FF from the same woman) as well as of given volumetric combinations thereof on sperm motility and acrosomal reactivity.

DESIGN

Prospective. Peritoneal fluid and FF were incubated separately or in given volumetric combinations (PF/FF = 100/0, 75/25, 50/50, 25/75, 0/100; vol/vol) with swim-up sperm suspensions.

SETTING

In vitro fertilization and general infertility clinic and laboratories.

PATIENTS, PARTICIPANTS

Women participants of the gamete intrafallopian transfer program (motility study, n = 20; acrosomal reaction study, n = 14). Sperm donors of the artificial insemination program and men with given sperm parameters.

INTERVENTIONS

Hormonal stimulation. Laparoscopy.

MAIN OUTCOME MEASURES

Progressive velocity and percentage of motile gametes measured with multiple-exposure photography. Acrosomal reactivity measured by an immunofluorescent technique.

RESULTS

Follicular fluid always influenced progressive motility and also sustained the number of motile gametes, as function of time, better than PF or the PF/FF mixtures (P less than 0.05). The acrosomal reactivity of sperm incubated in the various PF/FF combinations was low; after 5 hours only the FF-sperm suspensions showed a significant enhancement of acrosomally reacted gametes.

CONCLUSION

At ovulation, FF transmit positive (motility- and acrosomal reactivity-enhancing) signals to sperm, whereas PF may transmit positive, neutral, or negative signals (noise signals). The volumetric combination of FF and PF in the tubal environment, which may differ from cycle to cycle and from woman to woman, could therefore result in synergic (or antagonistic) effects on the sperm fertility potential.

Effect of platelet-derived growth factor on endometrial stromal cell proliferation in vitro: a model for endometriosis?

OBJECTIVE

To assess the direct effects of platelet-derived growth factor (PDGF), a macrophage secretory product structurally and functionally similar to substances released by peritoneal macrophages isolated from endometriosis patients, on endometrial cell proliferation.

DESIGN

Prospective analysis of cell proliferation in vitro.

SETTING

Proliferative phase endometrial stromal cells isolated from biopsy specimens were grown in short-term culture and served as a model for stromal components of endometriotic implants.

PATIENTS

Biopsies were obtained from regularly cycling volunteers without endometrial pathology.

INTERVENTIONS

Platelet-derived growth factor was added to nutrient medium in both the presence and absence of suboptimal (2.5%) calf serum (CS) supplements and a physiological estradiol (E2) concentration (10(-9) M).

MAIN OUTCOME MEASURES

Cumulative [3H]-thymidine incorporation as a reflection of cell proliferation.

RESULTS

Platelet-derived growth factor exerted a significant dose-dependent effect on stromal cell proliferation in both the presence and absence of CS (P less than 0.01). This effect was enhanced in, at best, an additive but not synergistic manner by E2 10(-9) M.

CONCLUSION

These data imply that macrophage secretory products such as PDGF may play a significant role in the maintenance or proliferation of endometriosis.

Absence of a direct effect of recombinant tumor necrosis factor-alpha on human sperm function and murine preimplantation development

OBJECTIVE

This study was designed to test the in vitro effects of human recombinant tumor necrosis factor (rTNF) on sperm motility, fertilization, and preimplantation development.

DESIGN

A sensitive enzyme immunoassay was used to determine half-lives of rTNF and confirm concentrations of cytokine throughout experimental conditions. Effect of rTNF on human sperm survival was measured by computer-assisted methodology, and effect on human sperm penetration was assessed by hamster ova penetration. Cytokine effect on murine gamete interaction was determined by in vitro fertilization (IVF). Murine preimplantation development was assessed by in vitro development of cryopreserved-thawed one-cell zygotes.

RESULTS

The half-life of rTNF was reduced by the addition of sperm to culture media (P less than 0.001). Sperm motility (P = 0.245) and hamster ova penetration (P = 0.62) were not altered by incubations in the presence of concentrations of rTNF up to 10,000 U/mL. Mouse IVF (P = 0.60) and preimplantation development (P = 0.56) were not altered by rTNF in concentrations up to 5,000 U/mL.

CONCLUSIONS

These results demonstrate rTNF by itself does not interfere with gamete function or early embryo development.

Role of peritoneal inflammation in endometriosis-associated infertility

This paper has discussed the evidence for the presence of infertility in patients with endometriosis and more critically reviewed some of the studies that have addressed the impact of various potential local peritoneal mechanisms that may lead to subfertility. Substantial evidence supports the notion that patients with endometriosis have reduced fecundability. Although several mechanisms, including, e.g., anatomic factors and ovulatory dysfunction, are possible, recent studies have pointed towards local inflammatory cells and their secretory products as being important mediators of subfertility. Ample evidence exists for the presence of an altered peritoneal inflammatory environment in patients with endometriosis. In addition, in vitro studies have identified peritoneal macrophages and their secretory products, specifically TNF-alpha as the most likely contributors to the reduced fecundability through effects on sperm function.

A comparative analysis of the cycle fecundity rates associated with combined human menopausal gonadotropin (hMG) and intrauterine insemination (IUI) versus either hMG or IUI alone

Human menopausal gonadotropin (hMG) superovulation combined with washed intrauterine insemination (IUI) has been advocated for the treatment of various forms of infertility when more traditional therapy has failed. To assess the relative efficacy of combined treatment with hMG and IUI compared with either hMG or IUI alone, pregnancy outcomes of the three treatment groups were compared in couples having infertility because of male factor, cervical factor, endometriosis, or unexplained. A total of 751 cycles were analyzed from 322 couples. The mean cycle fecundity rate associated with hMG/IUI therapy was significantly higher than either hMG or IUI therapy alone for all patients (hMG/IUI = 19.6%, hMG = 6.3%, IUI = 3.4%). The improvement in cycle fecundity rates with hMG/IUI therapy was also observed when the couples were separated by infertility diagnostic groups: male factor (hMG/IUI = 15.3%, hMG = 4.4%, IUI = 3.0%), cervical factor (hMG/IUI = 26.3%, hMG = 7.9%, IUI = 5.1%), endometriosis (hMG/IUI = 12.85%, hMG = 6.6%), and unexplained infertility (hMG/IUI = 32.6%, hMG = 5.5%, IUI = 0%). Moreover, in patients who had failed to conceive with hMG or IUI alone, the cycle fecundity rate when they were switched to hMG/IUI therapy equaled that of patients who received combined therapy from the onset. We conclude that cycle fecundity rates and cumulative pregnancy rates are significantly greater using a combination of hMG and IUI compared with either modality alone in the treatment of male factor, cervical factor, endometriosis, or unexplained infertility. Indeed, in couples with nontubal related infertility, cycle fecundity rates with hMG/IUI approach the rates seen with in vitro fertilization and gamete intrafallopian tube transfer.

Peritoneal fluid volume and sex steroids in the pre-ovulatory period in mild endometriosis

Twenty infertile women with laparoscopically confirmed mild endometriosis and ten women with tubal infertility underwent diagnostic laparoscopy 32 h after the onset of the endogenous luteinizing hormone (LH) surge during a spontaneous menstrual cycle. All visible peritoneal fluid was aspirated for assessment of volume and sex steroid content. There was no significant difference in peritoneal fluid volume or concentrations of oestradiol, progesterone and androstenedione between the two groups. Furthermore, in the endometriosis group there was no significant difference in peritoneal fluid volume and concentrations of sex steroids between those women who had been treated previously with danazol and those who were left untreated.

Elevated peritoneal fluid luteinizing hormone and prolactin concentrations in infertile women with endometriosis

In this study, we compared (Mann-Whitney U-test) the peritoneal fluid FSH, LH and PRL levels, measured by RIA, at the follicular and luteal phases of the menstrual cycle in women with (n = 43; age 25-44 years) and with no evidence of endometriosis (n = 35; age 25-39 years) who were considered as controls. Both follicular and luteal phase FSH concentrations of women with endometriosis were not statistically different (n = 22 vs 18; 0.32-5.8 vs 0.50-8.2 IU/l, P = 0.247; n = 13 vs 14; 0.6-6.5 vs 0.66-6.7 IU/l, P = 0.604) compared to their respective controls. In contrast to FSH, the concentrations of LH at follicular (n = 19 vs 17; 3.1-34.2 vs 2.3-12.2 IU/l, P = 0.01) and luteal (n = 17 vs 15; 2.1-95.4 vs 1.3-17.9 IU/l, P = 0.02) phases of the test group was significantly elevated at both phases of the cycle. With respect to differences in PRL concentrations at follicular phase no significant change (n = 21 vs 16; 1030-5800 vs 1305-4650 mIU/l; P = 0.255) was observed. The greatest difference in luteal PRL concentrations (P = 0.007) was obtained between the women with endometriosis and controls (n = 17 vs 17; 1895-8600 vs 1041-5000 mIU/l). The results suggest that disordered synchronization of neuroendocrine mechanisms controlling LH and PRL may be the underlying abnormality causing infertility in our group of patients with endometriosis.

Release of tumor necrosis factor-alpha by human peritoneal macrophages in vivo and in vitro

Tumor necrosis factor is a product of activated monocytes, macrophages, and lymphocytes that exerts a variety of effects in the host. Its cytotoxicity toward gametes has been suggested as a mechanism of how activated macrophages may cause subfertility, inasmuch as detectable levels of tumor necrosis factor have been reported in the peritoneal fluid of infertile patients. To further examine this issue we measured tumor necrosis factor activity in peritoneal fluid and its release in vitro from monocytes or peritoneal macrophages of patients undergoing laparoscopy because of either tubal ligation or infertility. Cytolytic activity was determined with a bioassay with sensitized mouse fibrosarcoma cells as target. Significant tumor necrosis factor activity (greater than 5 U/ml) was detected in 38% of the peritoneal fluid samples. A total of 43% of the peritoneal macrophage samples released significant tumor necrosis factor activity in vitro and all samples tested including peripheral monocytes released high levels of activity in the presence of bacterial endotoxin. The activity was released in vitro in a time-dependent manner. Thermal stability characteristics and neutralization with a specific antibody indicated that most of the activity in peritoneal fluid or released in vitro was that of tumor necrosis factor-alpha. Statistical analysis of tumor necrosis factor activity in peritoneal fluid in various diagnostic categories revealed a significantly elevated level in patients with endometriosis, as compared with fertile women. Endometriosis and pelvic adhesions were also significantly more likely to be associated with measurable levels of tumor necrosis factor activity released by peritoneal macrophages in vitro. Overall, because tumor necrosis factor-alpha levels were frequently detectable, it suggests that activation of peritoneal macrophages either by bacterial products or inflammatory conditions can occur in vivo. Moreover, these cells remain competent to release tumor necrosis factor in vitro.

Effect of peritoneal fluid on sperm motility and velocity distribution using objective measurements

The aim of this study was to analyze in vitro the effect(s) of peritoneal fluid (PF) on sperm motility. Seventy PFs obtained during laparoscopy were tested on motile-rich sperm suspensions. Proportion of motile sperm and velocity distribution were evaluated by multiple-exposure photography technique. At time (t) = 0, PFs increased both sperm parameters as compared with control (P less than 0.01). Maximum effect was observed at t = 5 hours: 32 (45%) PFs increased and 5 (7%) decreased the proportion of motile sperm, while 8 (11%) PFs increased and 4 (6%) decreased sperm velocity. No correlation was found between a particular infertile group and a definite negative effect. However, 70% of PFs from fertile women maintained or increased the proportion of motile sperm at t = 5 hours, compared with 36% in the total infertile group. Comparison of the sperm motility effect(s) of a given PF on different ejaculates revealed that the effects observed also were influenced by the sperm sample tested. In conclusion, PFs can maintain or increase the motility of spermatozoa as function of time. However, some PFs can inhibit sperm motility and these effect(s) can be influenced by the sperm sample.