Elevated interleukin-6 levels in peritoneal fluid of patients with pelvic pathology*†*Presented in part at the 38th Annual Meeting of the Society for Gynecologic Investigation, San Antonio, Texas, March 20 to 23, 1991.†Supported by a grant from the California Institute for Cancer Research, Los Angeles, California, and by grants CA 01588 from the National Institutes of Health and CA 09120 from the National Institutes of Health Tumor Immunology Institutional Training Grant, Bethesda, Maryland

Diagnostic Potential of Cytokine Biomarkers in Endometriosis: Challenges and Insights

Endometriosis is a common gynecological condition affecting approximately 10% of women of reproductive age, characterized by the abnormal presence of endometrial-like tissue outside the uterus. Although endometriosis was first described over 300 years ago, its underlying mechanisms remain poorly understood, and accurate, prompt diagnosis continues to be challenging. Currently, there is a lack of effective, non-invasive diagnostic methods, and available treatments often come with significant side effects and high recurrence rates. This has spurred interest in investigating the role of pro- and anti-inflammatory molecules, particularly cytokines, in endometriosis, as these molecules play a key role in its progression by influencing cell growth and differentiation. Previous studies suggest that various cytokines could serve as potential biomarkers for diagnosing endometriosis, as they are detectable in both serum and peritoneal fluid. This review provides an overview of the expression, origin, function, and regulation of specific cytokines in endometriosis, along with a brief discussion on their potential clinical implications for diagnosis. Due to the complexity of endometriosis, a panel of multiple biomarkers may ultimately be necessary for accurate diagnosis. It is essential to consider factors such as patient selection, sample collection, and analytical variability when initiating or evaluating biomarker studies.

Targeting interleukin-6 as a treatment approach for peritoneal carcinomatosis

Peritoneal carcinomatosis (PC) is a complex manifestation of abdominal cancers, with a poor prognosis and limited treatment options. Recent work identifying high concentrations of the cytokine interleukin-6 (IL-6) and its soluble receptor (sIL-6-Rα) in the peritoneal cavity of patients with PC has highlighted this pathway as an emerging potential therapeutic target. This review article provides a comprehensive overview of the current understanding of the potential role of IL-6 in the development and progression of PC. We discuss mechansims by which the IL-6 pathway may contribute to peritoneal tumor dissemination, mesothelial adhesion and invasion, stromal invasion and proliferation, and immune response modulation. Finally, we review the prospects for targeting the IL-6 pathway in the treatment of PC, focusing on common sites of origin, including ovarian, gastric, pancreatic, colorectal and appendiceal cancer, and mesothelioma.

Non-invasive diagnosis of endometriosis: Immunologic and genetic markers

Endometriosis, a benign gynecologic and chronic inflammatory disease, is defined by the presence of endometrial tissue outside the uterus characterized mainly by pelvic pain and infertility. Because endometriosis affects approximately 10% of females, it represents a significant socioeconomic burden worldwide having tremendous impact on daily quality of life. Accurate and prompt diagnosis is crucial for the management of this debilitating disorder. Unfortunately, diagnosis is typically delayed to lack of specific symptoms and readily accessible biomarkers. Although histopathologic examination remains the current gold standard, this approach is highly invasive and not applicable for early screening. Recent work has focused on the identification of reliable biomarkers including immunologic, ie, immune cells, antibodies and cytokines, as well as genetic and biochemical markers, ie, microRNAs, lncRNAs, circulating and mitochondrial nucleic acids, along with some hormones, glycoproteins and signaling molecules. Confirmatory research studies are, however, needed to more fully establish these markers in the diagnosis, progression and staging of these endometrial lesions.

Evaluation of BCL6 and SIRT1 as Non-Invasive Diagnostic Markers of Endometriosis

(1) Background: Endometriosis is characterized by the presence of endometrial glands and stroma outside of the uterus and is often associated with severe pelvic pain and infertility. Our study explored the utilization of B-Cell Lymphoma 6 (BCL6) and Sirtuin 1 (SIRT1) as potential biomarkers in serum, plasma, urine, and cervical mucus for a non-invasive diagnostic test for endometriosis. BCL6 was chosen based on its previously reported elevated expression in endometrial biopsies, and SIRT1 is co-expressed and upregulated in the endometrium of women with endometriosis. (2) Methods: BCL6 and SIRT1 levels were measured using enzyme-linked immunoassay (ELISA) in samples from 20 women with endometriosis (ten with stages I/II and ten with stages III/IV) and ten women without endometriosis. (3) Results: Levels of SIRT1 in sera showed a statistically significant elevation in advanced stages III/IV compared to controls and stages I/II. No significant differences were found in other bodily fluids for SIRT1 or any bodily fluids tested for BCL6. (4) Conclusions: These results suggest some potential of SIRT1 expression within serum as a predictor of advanced asymptomatic stages of endometriosis. Using immunohistochemistry (IHC) staining and H-SCORE values for the elevated BCL6 (and potentially SIRT1) levels in endometrial biopsy samples seems to have higher diagnostic potential based on the previously published studies.

Post-Operative Adhesions: A Comprehensive Review of Mechanisms

Post-surgical adhesions are common in almost all surgical areas and are associated with significant rates of morbidity, mortality, and increased healthcare costs, especially when a patient requires repeat operative interventions. Many groups have studied the mechanisms driving post-surgical adhesion formation. Despite continued advancements, we are yet to identify a prevailing mechanism. It is highly likely that post-operative adhesions have a multifactorial etiology. This complex pathophysiology, coupled with our incomplete understanding of the underlying pathways, has resulted in therapeutic options that have failed to demonstrate safety and efficacy on a consistent basis. The translation of findings from basic and preclinical research into robust clinical trials has also remained elusive. Herein, we present and contextualize the latest findings surrounding mechanisms that have been implicated in post-surgical adhesion formation.

Prevention of Post-Operative Adhesions: A Comprehensive Review of Present and Emerging Strategies

Post-operative adhesions affect patients undergoing all types of surgeries. They are associated with serious complications, including higher risk of morbidity and mortality. Given increased hospitalization, longer operative times, and longer length of hospital stay, post-surgical adhesions also pose a great financial burden. Although our knowledge of some of the underlying mechanisms driving adhesion formation has significantly improved over the past two decades, literature has yet to fully explain the pathogenesis and etiology of post-surgical adhesions. As a result, finding an ideal preventative strategy and leveraging appropriate tissue engineering strategies has proven to be difficult. Different products have been developed and enjoyed various levels of success along the translational tissue engineering research spectrum, but their clinical translation has been limited. Herein, we comprehensively review the agents and products that have been developed to mitigate post-operative adhesion formation. We also assess emerging strategies that aid in facilitating precision and personalized medicine to improve outcomes for patients and our healthcare system.

Endometriosis Pain Management: a Review

PURPOSE OF REVIEW

The purpose of this review is to summarize the up-to-date pain management options and recommendations for the challenging disease, endometriosis.

RECENT FINDINGS

The mainstays of endometriosis advances of both surgical and medical management continue to evolve. Experimental pharmaceuticals include Gestirone, and aromatase inhibitors have shown promise but are still under scrutiny. Surgical techniques include laparoscopic uterosacral nerve ablation/resection and presacral neurectomy. No studies have directly compared medical versus surgical management, and as such, no one treatment modality can be recommend as superior to the other. Patients may initially be given a medical diagnosis and treated with nonsteroidal anti-inflammatory drugs, neurolepitcs, OCP, GNRH agonists/antagonists, and Danazol. Assessing the success of these regimens has proved difficult. Surgical management relies on various methods including excision/ablation of the lesions, nerve ablation, neurectomy, hysterectomy, and oophorectomy.

Abnormal Pathways in Endometriosis in Relation to Progesterone Resistance: A Review

Introduction

Endometriosis is an estrogen-dependent disorder, and recent studies suggest that progesterone resistance may contribute to the development and pathophysiology of the disorder. Based on this, identification of genetic and molecular perturbations in the endometrium of women with endometriosis is an important step towards understanding the pathogenesis of the disease, and the development of novel treatment and diagnostic strategies.

Methods

A systematic literature search in PubMed and Embase was performed, and 118 articles were identified for further screening. Two reviewers performed article screening independently using Covidence, and 16 studies fulfilled the inclusion criteria. The Newcastle-Ottawa Scale was used to assess the quality of these studies.

Results

This review presents data from eutopic endometrial biopsies from women with and without endometriosis. Several biomarkers related to a downregulated progesterone response were identified and discussed in detail.

Conclusions

Our review demonstrates significant results concerning the biomarkers investigated, which may substantiate the theory of progesterone resistance in women with endometriosis. However, further research is necessary to determine their specific role and relevance.

Endometrial BCL6 Overexpression in Eutopic Endometrium of Women With Endometriosis

The objective of this study was to examine B-cell CLL/lymphoma 6 (BCL6) expression in human eutopic endometrium across the menstrual cycle in women with and without endometriosis and to establish a cutoff for future studies. This design was a series of case-control studies in tertiary University teaching hospitals. We examined BCL6 expression by messenger RNA and immunohistochemically in prospectively collected samples in both the proliferative (P) and the secretory phases. BCL6 is minimally increased in the mid-secretory phase of the menstrual cycle compared to the P phase in normal patients. BCL6 protein expression was significantly higher in the secretory phase of patients with endometriosis (n = 29) versus fertile controls without endometriosis at laparoscopy (n = 20; P < .0001). Normal fertile controls (n = 28) recruited for endometrial biopsy also had low levels of secretory phase BCL6 expression compared to women with unexplained infertility (UI; n = 119). A receiving-operator characteristic analysis of these data revealed an area under the curve of 94% (95% confidence interval 85%-100%; P < .0001) with an HSCORE cutoff of 1.4 to differentiate cases with and without endometriosis. Using this cutoff value, BCL6 was positive in 88% of cases with UI. Laparoscopic examination of a subset of 65 patients confirmed abnormalities in 98% of cases; 61 (93.8%) were found to have endometriosis, 3 (4.6%) with hydrosalpinx, and 1 (1.5%) with a normal pelvis. These data suggest that BCL6 is a promising candidate as a single diagnostic biomarker for detection of endometriosis in women with otherwise UI and may be associated with endometrial dysfunction, including progesterone resistance.

Does dienogest influence the inflammatory response of endometriotic cells? A systematic review

OBJECTIVE AND DESIGN

A systematic review of all literature was done to assess the ability of the progestin dienogest (DNG) to influence the inflammatory response of endometriotic cells.

MAIN OUTCOME MEASURES

In vitro and in vivo studies report an influence of DNG on the inflammatory response in eutopic or ectopic endometrial tissue (animal or human).

RESULTS

After strict inclusion criteria were satisfied, 15 studies were identified that reported a DNG influence on the inflammatory response in endometrial tissue. These studies identified a modulation of prostaglandin (PG) production and metabolism (PGE2, PGE2 synthase, cyclo-oxygenase-2 and microsomal PGE synthase-1), pro-inflammatory cytokine and chemokine production [interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, monocyte chemoattractant protein-1 and stromal cell-derived factor-1], growth factor biosynthesis (vascular endothelial growth factor and nerve growth factor) and signaling kinases, responsible for the control of inflammation. Evidence supports a progesterone receptor-mediated inhibition of the inflammatory response in PR-expressing epithelial cells. It also indicated that DNG inhibited the inflammatory response in stromal cells, however, whether this was via a PR-mediated mechanism is not clear.

CONCLUSIONS

DNG has a significant effect on the inflammatory microenvironment of endometriotic lesions that may contribute to its clinical efficacy. A better understanding of the specific anti-inflammatory activity of DNG and whether this contributes to its clinical efficacy can help develop treatments that focus on the inhibition of inflammation while minimizing hormonal modulation.

Aberrant activation of signal transducer and activator of transcription-3 (STAT3) signaling in endometriosis

STUDY QUESTION

Are STAT3 signaling molecules differentially expressed in endometriosis?

SUMMARY ANSWER

Levels of phospho-STAT3 and HIF1A, its downstream signaling molecule, are significantly higher in eutopic endometrium from women with endometriosis when compared with women without the disease.

WHAT IS KNOWN ALREADY

Endometriosis is an estrogen-dependent inflammatory condition. Interleukin 6 (IL-6) is an inflammatory survival cytokine known to induce prolonged activation of STAT3 via association with the IL-6 receptor.

STUDY DESIGN, SIZE, DURATION

Cross-sectional measurements of STAT3 and HIF1A protein levels in eutopic endometrium from women with endometriosis versus those without.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Levels of phospho-STAT3 (pSTAT3) and HIF1A were examined in the endometrium of patients with and without endometriosis as well as in a non-human primate animal model using western blot and immunohistochemical analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Levels of pSTAT3 were significantly higher in the eutopic endometrium from women with endometriosis when compared with women without the disease in both the proliferative and secretory phases. HIF1A is known to be stabilized by STAT3 and IL-6. Our immunohistochemistry results show abundant HIF1A expression within the eutopic endometrial epithelial cells of women with endometriosis. Furthermore, pSTAT3 and HIF1A proteins are co-localized in endometriosis. This aberrant activation of pSTAT3 and HIF1A is confirmed by sequential analysis of eutopic endometrium using a baboon animal model of induced endometriosis. Lastly, we confirmed this IL-6 induction of both STAT3 phosphorylation and HIF1A mRNA expression in Ishikawa human endometrial adenocarcinoma cell line.

LIMITATIONS, REASONS FOR CAUTION

Ishikawa cancer cell line was used to study a benign disease. The peritoneal fluid contains various inflammatory cytokines in addition to IL-6 and so it is possible that other cytokines may affect the activity and expression of STAT3 signaling molecules.

WIDER IMPLICATIONS OF THE FINDINGS

Our results imply that aberrant activation of STAT3 signaling plays an important role in the pathogenesis of endometriosis. Our findings could progress in our understanding of the etiology and pathophysiology of endometriosis and potential therapeutic interventions by targeted pharmacological.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by NIH R01 HD067721 (to S.L.Y and B.A.L) and NIH R01 HD057873 and American Cancer Society Research Grant RSG-12-084-01-TBG (to J.-W.J.). There are no conflicts of interest.

Inflammation and nerve fiber interaction in endometriotic pain

Endometriosis is an extremely prevalent estrogen-dependent condition characterized by the growth of ectopic endometrial tissue outside the uterine cavity, and is often presented with severe pain. Although the relationship between lesion and pain remains unclear, nerve fibers found in close proximity to endometriotic lesions may be related to pain. Also, women with endometriosis pain develop central sensitization. Endometriosis creates an inflammatory environment and recent research is beginning to elucidate the role of inflammation in stimulating peripheral nerve sensitization. In this review, we discuss endometriosis-associated inflammation, peripheral nerve fibers, and assess their potential mechanism of interaction. We propose that an interaction between lesions and nerve fibers, mediated by inflammation, may be important in endometriosis-associated pain.

Locally increased concentrations of inflammatory cytokines in an experimental intraabdominal adhesion model

BACKGROUND

Peritoneal adhesions may cause bowel obstruction, infertility, and pain. This study investigated cytokines, proteins and growth factors thought to promote formation of adhesions in an experimental intraabdominal adhesion model.

METHODS

Male Sprague-Dawley rats were subjected to laparotomy, cecal abrasion, and construction of a small bowel anastomosis and examined at various time points after surgery. Concentrations of cytokines and growth factors in plasma and peritoneal fluid were analyzed using electrochemoluminescence and quantitative sandwich enzyme immunoassay technique.

RESULTS

Concentrations of interleukin-6 (IL-6), interleukin-1beta (IL-1β), and tumor necrosis factor alpha (TNF-α) increased in peritoneal fluid from 6h after incision. Plasma concentrations of IL-6 increased at 6h, but plasma concentrations of IL-1β and TNF-α remained low. Peritoneal fluid concentrations of platelet-derived growth factor-BB (PDGF-BB), transforming growth factor beta1 (TGF-β1), vascular endothelial growth factor (VEGF), tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) were below detection levels at all time points.

CONCLUSION

Early elevations of IL-6, IL-1β, and TNF-α concentrations in peritoneal fluid correlated to adhesion formation in this rodent model. Our model is relevant and reproducible, suitable for intervention, and indicates that antiadhesion strategies should be early, local and not systemic.

Peritoneal cytokines and adhesion formation in endometriosis: an inverse association with vascular endothelial growth factor concentration

OBJECTIVE

To evaluate inflammatory/angiogenic cytokines-interleukin-1β (IL-1β), IL-6, IL-8, IL-12, interferon-γ (IFN-γ), tumor necrosis factor (TNF), and vascular endothelial growth factor A (VEGF-A)-in the peritoneal fluid of patients with endometriosis in relation to the occurrence and severity of pelvic adhesions and in control women without pelvic pathology.

DESIGN

Case-control study.

SETTING

University research institution and hospital.

PATIENT(S)

Sixty-five women with laparoscopically and histopathologically confirmed endometriosis, including 40 women with pelvic adhesions, and 37 control women without pelvic pathology.

INTERVENTION(S)

Peritoneal fluid aspirated during routine diagnostic laparoscopic examination.

MAIN OUTCOME MEASURE(S)

Cytokines evaluated in the peritoneal fluid via specific enzyme-linked immunosorbent assays.

RESULT(S)

Endometriosis and the revised American Fertility Society score of this disease were associated with statistically significantly increased levels of peritoneal IL-6 and IL-8 whereas the incidence and score of endometriosis-related pelvic adhesions were negatively associated with increased levels of VEGF-A. Notably, the concentration of VEGF-A predicted adhesion development and severity after adjustment for endometriosis severity. The adhesion score also correlated with increased levels of IL-6; however, after adjustment for endometriosis severity, the effect of this cytokine was no longer statistically significant.

CONCLUSION(S)

Increased levels of VEGF-A may be associated with a decreased rate of pelvic adhesion formation in the course of endometriosis.

Peptide inhibitors of MK2 show promise for inhibition of abdominal adhesions

BACKGROUND

Abdominal adhesions are a common side effect of surgical procedures with complications including infertility, chronic pain, and bowel obstruction, which may lead to the need for surgical lyses of the adhesions. Mitogen-activated protein kinase-activated protein kinase 2 (MK2) has been implicated in several diseases, involving inflammation and fibrosis. Thus, the development of a cell-penetrating peptide (CPP) that modulates MK2 activity may confer therapeutic benefit after abdominal surgery in general and more specifically after bowel anastomosis.

METHODS

This study evaluated the function of a CPP inhibitor of MK2 in human mesothelial cells and in a rat bowel anastomosis model. To determine IC50 and basic specificity, kinase inhibition was performed using a radiometric assay. Enzyme-linked immunoassay (ELISA) was used to evaluate interleukin-6 (IL-6) expression in response to IL-1β and tumor necrosis factor-α (TNF-α) stimulation in vitro to validate MK2 kinase inhibition. Following bowel anastomosis (10 rats for each control and treatment at 4 and 10 d), the rats were evaluated for weight loss, normal healing (colonic burst strength and hydroxyproline content at the anastomosis), and number and density of adhesions.

RESULTS

The IC50 of the MK2 inhibitor peptide (22 μM) was similar to that of the nonspecific small molecule rottlerin (IC50 = 5 μM). The MK2 inhibitor peptide was effective at suppressing IL-1β and TNF-α stimulated IL-6 expression in mesothelial cells. In vivo, the MK2 inhibitor peptide was effective at suppressing both the density and number of adhesions formed as a result of bowel an anastamosis. Importantly, the peptide had no negative effect on normal healing.

CONCLUSIONS

In conclusion, the peptide inhibitor of MK2, MMI-0100, has the potential to significantly reduce inflammation through suppression of inflammatory cytokine expression and showed promise as a therapeutic for abdominal adhesions.

Chronic pelvic pain and endometriosis: translational evidence of the relationship and implications

BACKGROUND

Many clinicians and patients believe that endometriosis-associated pain is due to the lesions. Yet causality remains an enigma, because pain symptoms attributed to endometriosis occur in women without endometriosis and because pain symptoms and severity correlate poorly with lesion characteristics. Most research and reviews focus on the lesions, not the pain. This review starts with the recognition that the experience of pain is determined by the central nervous system (CNS) and focuses on the pain symptoms.

METHODS

Comprehensive searches of Pubmed, Medline and Embase were conducted for current basic and clinical research on chronic pelvic pain and endometriosis. The information was mutually interpreted by a basic scientist and a clinical researcher, both in the field of endometriosis. The goal was to develop new ways to conceptualize how endometriosis contributes to pain symptoms in the context of current treatments and the reproductive tract.

RESULTS

Endometriotic lesions can develop their own nerve supply, thereby creating a direct and two-way interaction between lesions and the CNS. This engagement provides a mechanism by which the dynamic and hormonally responsive nervous system is brought directly into play to produce a variety of individual differences in pain that can, in some women, become independent of the disease itself.

CONCLUSIONS

Major advances in improving understanding and alleviating pain in endometriosis will likely occur if the focus changes from lesions to pain. In turn, how endometriosis affects the CNS would be best examined in the context of mechanisms underlying other chronic pain conditions.

Pathogenesis of endometriosis: the role of defective 'immunosurveillance'

OBJECTIVE

To analyse the aetiopathogenesis and the role of defective 'immunosurveillance' in endometriosis.

METHOD

Review of studies on the pathogenesis of endometriosis, focusing particularly on novel molecules which express adhesive or proteolytic properties. Hypotheses addressing the role of oxidative stress in endometriosis were also reviewed.

RESULTS

Endometriosis is a multifactorial disease associated with a general inflammatory response aiming to clear the peritoneal cavity from the ectopic endometriotic cells and tissue. Modern theories suggest that this inflammatory response creates an environment that may promote implantation and proliferation due to defective 'immunosurveillance'.

CONCLUSION

The modern interpretation of the theory of reflux menstruation holds that women destined to develop endometriosis have a deficient immune system, which cannot defend against regurgitated endometrial cells. New findings on genetics, immune modulation, and secreted products of endometriotic lesions of affected women have given insight into the pathogenesis of this disorder and may serve as the background for new treatments of endometriosis-associated pain and 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.

Is Endometriosis Associated with Systemic Subclinical Inflammation?

Endometriosis is a pelvic inflammatory process with altered function of immune-related cells and increased number of activated macrophages in the peritoneal environment that secrete various local products, such as growth factors and cytokines. The elevation of cytokines and other factors in the peritoneal fluid is accompanied by the elevation of similar factors, such as CRP, SAA, TNF-alpha, MCP-1, IL-6, IL-8 and CCR1, in the peripheral blood of patients with endometriosis. CD44+ and CD14+ monocytes are significantly increased, while CD3+ T lymphocytes and CD20+ B lymphocytes show modest, but significant decrease in peripheral blood of women with endometriosis. This indicates that endometriosis could be viewed as a local disease with systemic subclinical manifestations. This review provides an overview of data on the changes of various factors in peripheral blood and their potential use as diagnostic tools in patients with endometriosis.

Immunological factors and their role in the genesis and development of endometriosis ARTICLE HAS BEEN RETRACTED

The article presents an overview of immunological factors and their role in the genesis and development of endometriosis, with emphasis on inflammatory cytokines and growth and adhesion factors. Although retrograde menstruation is a common phenomenon among women of reproductive age, not all women with retrograde menstruation suffer the disease. Development of endometriosis seems to be a complex process, facilitated by several factors, including quantity and quality of endometrial cells in peritoneal fluid (PF), increased inflammatory activity in PF, increased endometrial-peritoneal adhesion and angiogenesis, reduced immune surveillance and clearance of endometrial cells, and increased production of autoantibodies against endometrial cells. Potential biomarkers like cytokines and autoantibodies, upregulated during development of endometriosis, seem useful in the development of a non-surgical diagnostic tool. In this review work, the immune role in endometriosis is examined through the role of immunological factors in the genesis and development of the disease. Furthermore, it could be concluded that, although endometriosis can be treated using hormonal suppression, there is a need today for non-hormonal drugs, probably to modulate immune function, in order to confront the disease and alleviate pain or infertility without inhibition of ovulation.

The interleukin-6 -174G/C promoter polymorphism is not associated with endometriosis in South Indian women

OBJECTIVE

To investigate the association of the -174 G/C promoter polymorphism of the interleukin-6 (IL-6) gene with endometriosis in South Indian women.

METHODS

The genotype frequencies of the common IL-6 -174 G/C polymorphism were compared in infertility patients with (n = 232) and without (n = 210) endometriosis using polymerase chain reaction (PCR) and sequencing analysis.

RESULTS

The genotype frequencies among the cases and controls were G/G 62.9% and 71.9%, G/C 34.1% and 25.2%, and C/C 3.0% and 2.9%. The G and C allele frequencies were 80% and 84.6%, and 20% and 15.4%, respectively. There were no statistically significant differences in the genotype distributions or allele frequencies between the cases and controls (P = .12).

CONCLUSIONS

The present study demonstrates no significant association between the IL-6 -174 G/C promoter polymorphism and endometriosis in South Indian women.

Interleukin-6- and tumour necrosis factor alpha-mediated expression of hepatocyte growth factor by stromal cells and its involvement in the growth of endometriosis

BACKGROUND

We investigated the expression of the hepatocyte growth factor (HGF) gene and protein by the stromal cells derived from women with or without endometriosis and its regulation by interleukin-6 (IL-6) and tumour necrosis factor alpha (TNFalpha).

METHODS

Stromal cells immunoreactive to vimentin were isolated from the eutopic and ectopic endometrium of 18 infertile women with endometriosis and 12 women without endometriosis. The production of HGF in the culture media of basal and IL-6- or TNFalpha-stimulated stromal cells was examined with an enzyme-linked immunosorbent assay. The mRNA expression of HGF and its receptor c-Met in the stroma was investigated by RT-PCR. The localization of HGF and c-Met in isolated stromal cells and in intact tissue was examined by immunohistochemistry. The effect of HGF on the growth of stromal cells alone or in combination with IL-6 or TNFalpha was examined in a bromodeoxyuridine (BrdU) incorporation study.

RESULTS

The production of HGF in the culture medium of stromal cells was significantly increased after single or combined treatment with either IL-6 or TNFalpha when compared with non-treated cells. The production of HGF by stromal cells derived from the eutopic endometrium of women with endometriosis was significantly higher than that of cells from women without endometriosis. This effect was paralleled by increased expression of HGF and c-Met mRNA, as demonstrated by RT-PCR. The BrdU incorporation study indicated that the addition of HGF enhanced the growth of endometrial and endometriotic stroma alone or in combination with IL-6 or TNFalpha.

CONCLUSION

IL-6 and TNFalpha are involved in the production of HGF by endometrial stromal cells and may be involved in the growth of endometriosis by an autocrine mechanism.

Regulation of hepatocyte growth factor by basal and stimulated macrophages in women with endometriosis

BACKGROUND

The different macromolecules as secreted by macrophages in the pelvic environment are believed to enhance the growth of endometriosis. However, the possible mediator that stimulates macrophages for the production of different growth factors is not well described. Therefore, we investigated the possible production of hepatocyte growth factor (HGF) by the basal and lipopolysaccharide (LPS)-stimulated macrophages derived from women with or without endometriosis.

METHODS

Using primary culture and 4-well chamber slides, adherent macrophages immunoreactive to CD68 were isolated from the peritoneal fluid (PF) of 20 infertile women with endometriosis and 12 women without endometriosis. The proliferation of basal and LPS-treated macrophages was investigated by the dimethylthiazole tetrazolioum bromide (MTT) assay. The production of HGF in the culture media of basal and LPS-stimulated macrophages was examined by enzyme-linked immunosorbent assay. The expression of mRNA for HGF and its receptor, c-Met, in the macrophages was investigated by RT-PCR. The effect of HGF on the growth of endometrial cells and macrophages was analysed by bromodeoxyuridine (BrdU) incorporation.

RESULTS

A >100% increase in the proliferation of peritoneal macrophages derived from women with endometriosis, and particularly of those harbouring dominant red lesions, was observed after treatment with LPS (P<0.05). A 4- and 3-fold increase in the production of HGF was observed by the LPS-treated macrophages derived from women with stage I-II endometriosis and stage III-IV endometriosis, respectively, when compared with non-LPS-treated macrophages (P<0.001). At the transcriptional level, we found a 5-fold increase in HGF mRNA expression in LPS-treated macrophages versus basal macrophages in women with endometriosis (P<0.001). The BrdU incorporation study indicates that 10-100 ng/ml of HGF enhanced the growth of endometrial epithelial cells, stroma and macrophages (approximately 50% increase) derived from women with endometriosis (all P<0.05).

CONCLUSION

LPS could be an inflammatory mediator of macrophage stimulation in the pelvic microenvironment. Besides mesenchymal cells, HGF is also produced by peritoneal macrophages and is possibly involved in the growth of endometriosis.

Increase of activated mast cells in human endometriosis

PROBLEM

The proliferation of stromal cells in endometriosis promotes extensive adhesion; therefore, the morphological analysis of stromal lesions is important in the investigation of the pathogenesis of endometriosis.

METHOD OF STUDY

In this study, the morphological and numeric comparisons of degranulated mast cells were performed between endometriotic lesions and comparative regions (eutopic endometrium and normal uterine serosa) of patients with and without endometriosis.

RESULTS

In cases of endometriosis, diffuse infiltration of numerous mast cells was observed throughout the stromal lesions. These mast cells exhibited degranulation, and scattered granules were also observed. In the eutopic endometrium and normal uterine serosa of both the endometriosis patients and the controls, mast cells were rarely detected.

CONCLUSIONS

These results suggest that an abnormal immune response, specifically a hypersensitivity reaction, is strongly related to endometriosis; our findings will be helpful in the development of methods for the treatment of endometriosis.

Reduction of estrogen production by interleukin-6 in a human granulosa tumor cell line may have implications for endometriosis-associated infertility

OBJECTIVE

To examine the effect of interleukin-6 (IL-6) on estrogen production and aromatase activity using a human granulosa tumor cell line (KGN cells). The involvement of the mitogen-activated protein kinase (MAPK) cascade in the inhibitory effects of IL-6 on estrogen production was also evaluated.

DESIGN

Molecular and biological studies of KGN cells.

SETTING

Department of Obstetrics and Gynecology, Tottori University Hospital, Yonago, Japan.

MAIN OUTCOME MEASURE(S)

Gene expression of IL-6 and the IL-6 receptor was analyzed by reverse transcription-polymerase chain reaction and Southern blot analysis. KGN cells were cultured for 48 hours with IL-6 (0.1-10 ng/mL) or IL-6 (10 ng/mL) plus a mitogen activated protein kinase-extracellular signal regulated kinase kinase 1/2 (MEK1/2) inhibitor U0126 (10 microM). Estradiol concentration in the culture supernatants was measured by means of enzyme immunoassay, [1beta-(3)H] androstenedione was added to the cell lysate supernatant, and aromatase activity was determined by measuring the amount of [(3)H] H(2)O released upon the conversion of [1beta-(3)H] androstenedione to estrone. To examine the activation of intracellular signal transduction molecules induced by IL-6, the phosphorylation of Stat3, p38 MAPK, and extracellular signal-regulated kinase 1/2 (ERK1/2) was examined by Western blotting.

RESULT(S)

Gene expression of IL-6 and its receptor was detected in KGN cells. Estradiol secretion was significantly inhibited by adding IL-6, which also suppressed aromatase activity to 50% of the control. In addition, pretreatment with U0126 restored the IL-6-induced suppression of aromatase activity. IL-6 markedly enhanced the phosphorylation of ERK1/2, but not Stat3 and p38 MAPK. U0126 markedly reduced the level of the IL-6-induced phosphorylation of ERK1/2.

CONCLUSION(S)

These findings demonstrate that IL-6 may reduce estrogen production via the MAPK signal pathway in human granulosa cells. The results may support the notion that IL-6 is related to impaired estrogen biosynthesis in patients with endometriosis.

The effect of tranexamic acid in fibrin sealant on adhesion formation in the rat

The objective of the research was to determine the effect of the type, dose, and volume of anti-fibrinolytic agents (tranexamic acid, aprotinin) added to fibrin formulations, on adhesion development. Adhesions were induced in 228 male rats by creating apposing parietal and visceral peritoneal defects. Animals were randomized to receive no treatment or a fibrin formulation containing aprotinin or tranexamic acid. Seven days later the incidence of adhesions, and the force and energy required to detach them, were determined. Adhesions developed in 13/13 rats in the control and aprotinin groups. Treatment with fibrin (100 mg/ml tranexamic acid) resulted in adhesions in 4/14 rats (as strips, p < or = 0.0005), 4/10 rats (as spray, p < or = 0.0036), and 12/15 rats (by drip). The reduction of adhesions was dependent on the concentration of tranexamic acid with strip and spray application. Using commercial formulations, tranexamic-acid-containing fibrin (10/15, p = 0.042), but not aprotinin-containing fibrin (13/15), reduced the incidence of side-wall adhesions from 15/15 in controls. Fibrin containing either tranexamic or aprotinin reduced the incidence and severity of adhesions. This effect was greater when tranexamic acid was used and was dependent on the mode of administration, the volume, and to a degree, the concentration of tranexamic acid.

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.

Lexipafant inhibits postsurgical adhesion formation

BACKGROUND

PAF and its antagonists have been studied in the pathophysiology of various inflammatory conditions. This study investigates the effects of a platelet activating factor antagonist, lexipafant, on peritoneal adhesion formation and wound healing.

MATERIALS AND METHODS

Forty-eight Wistar albino rats (300-350 g) were divided into four equal groups; adhesion-induced lexipafant (AL), adhesion-induced saline (AS), sham-operated lexipafant (SL), and sham-operated saline (SS). All rats underwent a midline laparotomy under sterile conditions. The anterior wall of the left uterine horn was scraped to cause hemorrhages in adhesion-induced groups. Following peritoneal injections of either saline or lexipafant, the incisions were closed in layers. On the 14th day, the rats were killed and adhesions were scored from 0 (none) to 4 (dense). Tissue samples from the adhesions and the left horn of uterus were examined biochemically for hydroxyproline content, and serum IL-6 levels were determined.

RESULTS

The adhesion formation score was significantly increased in the AS group compared to the SL and AL groups (P < 0.001). The IL-6 levels of the AS group were higher than those of the other groups (P < 0.05). There was no significant difference in hydroxyproline content between groups (P > 0.05).

CONCLUSIONS

Lexipafant plays a role in the prevention of adhesion formation without affecting wound healing.

Autoantibody responses to carbohydrate epitopes in endometriosis

Autoantibody responses to endometrial and serum antigens are a common feature of endometriosis. We have shown that the serum autoantibody response in endometriosis to a number of previously identified antigens, including alpha2-Heremans Schmidt glycoprotein and carbonic anhydrase, is specific for a carbohydrate epitope common to these proteins. Removal of carbohydrate moieties from these antigens resulted in a loss of antibody binding. Antibody reactivity was abolished following adsorption with the lectin jacalin, which specifically binds the Thomsen-Friedenreich (T) antigen (Gal beta1-3GalNAc). Demonstration that the autoantibodies also reacted with other Thomsen-Friedenreich antigen-bearing proteins, such as serum IgA1, hemopexin, and MMP-9, confirmed that this glycotope is involved in the autoantibody response. However, the autoantibody binding requires the presence of at least one sialic acid residue. Thus, the glycotope involved may be a sialylated T antigen. These findings allow us to hypothesize a number of mechanisms whereby the autoimmune response plays a direct role in several aspects of the disease process. The proposed mechanisms take into account the salient endocrine dependency of endometriotic lesions and other aspects of the disease process such as aberrant matrix metalloproteinase function and the ability of endometrial cells to implant at ectopic sites. The anti-T-like response may also be indicative of an underlying genetic defect in glycosylation or in the control of glycosylation by steroid sex hormones. Further characterization of this autoimmune response may prove useful in the development of serum-based diagnostic tests for endometriosis and may lead to the development of therapeutic strategies.

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.

Autoantibodies in endometriosis sera recognize a Thomsen-Friedenreich-like carbohydrate antigen

Autoantibody responses to endometrial antigens are a common feature of endometriosis. Antibody responses to a number of serum and tissue antigens such as alpha(2)-Heremans Schmidt glycoprotein (alpha(2)-HSG), transferrin, and carbonic anhydrase have been identified. The nature of the epitopes recognized on these proteins has not been determined. In this study we show that the serum antibody response to alpha(2)-HSG and carbonic anhydrase is against a common carbohydrate epitope which is also expressed on bovine fetuin. Removal of carbohydrate moieties from these antigens resulted in loss of antibody binding. Antibody reactivity with alpha(2)-HSG, fetuin and other antigens was removed by binding with the lectin jacalin. Jacalin specifically binds the Thomsen-Friedenreich antigen (Galbeta1-3GalNAc). Demonstrating that the autoantibodies also reacted with other Thomsen-Friedenreich antigen-bearing proteins, serum IgA1 and haemopexin confirmed an association with this epitope. These antigens have not been previously described as autoantigens in endometriosis and are of interest since they raise the possibility that this autoimmune response may either play a direct role in the disease process or reflect an abnormality of glycosylation in endometriosis. These results may also prove useful in the development of a serum diagnostic test for endometriosis.

Immunobiology of endometriosis

OBJECTIVE

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

DESIGN

Literature survey.

RESULT(S)

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

CONCLUSION(S)

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

Peritoneal fluid interleukin-6 in women with chronic pelvic pain

OBJECTIVE

To determine the relationship between peritoneal fluid concentrations of interleukin-6 (IL-6) and chronic pelvic pain symptomatology in women with adhesions, endometriosis, or no obvious intraperitoneal pathology.

DESIGN

Clinical research study.

SETTING

Healthy volunteers in an academic research environment.

PATIENT(S)

Reproductive-aged women undergoing laparoscopy for the diagnosis of pelvic pain, infertility, or sterilization were selected.

INTERVENTION(S)

Peritoneal fluid was collected at the time of the laparoscopy and later assayed for IL-6. Subjects completed a pelvic pain questionnaire, and operative reports were used to obtain the underlying diagnosis.

MAIN OUTCOME MEASURE(S)

Interleukin-6 concentrations.

RESULT(S)

No correlation between the presence or absence of pelvic pain, findings of adhesions or endometriosis, and the concentration of peritoneal fluid IL-6 was observed.

CONCLUSION(S)

The cytokine IL-6 does not seem to play a role in the genesis of chronic pelvic pain in women with adhesions or endometriosis.

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.

Changes of cytokines levels in peritoneal fluids of patients with endometriosis and its effect on reproductive activity

To study the changes of cytokines in peritoneal fluids of patients with endometriosis and their effects on reproductive activity, levels of tumor necrosis factor (TNF) and interleukin 6 (IL-6) in peritoneal fluids and peritoneal macrophages' culture supernatant were studied by using enzyme linked immunoassay (ELISA) in 14 infertile patients with endometriosis (EMT group) and 11 infertile women with normal pelvis (control group). The effects of peritoneal fluids in patients with endometriosis in vitro on sperm motility and development of 2-cell mouse embryos were also studied. The results showed that the levels of TNF and IL-6 in peritoneal fluids and peritoneal macrophages' supernatant in EMT group were elevated significantly as compared with those in the control group (P < 0.01). The percent of sperm straight line movement and total sperm motility were decreased significantly in EMT group (P < 0.01). The percent of 2-cell mouse embryos developing to 16-cells was 32.5% in EMT group, while 47.6% in control group after 48 h co-culture with peritoneal fluid (P < 0.01). It is likely that the elevation of peritoneal fluid cytokines in patients with endometriosis may play a role in infertility associated with endometriosis.

Effects of hypogastric neurectomy on escape responses to uterine distention in the rat

Anatomical data indicate that the rat uterine horn is innervated primarily by afferent fibers in the hypogastric nerves, suggesting that hypogastric neurectomy, but not pelvic or pudendal neurectomy, should eliminate behavioral responses to uterine horn stimulation. To test this hypothesis, detection and escape responses of rats to different volumes of uterine horn distention (via an indwelling intrauterine balloon) were compared before and after bilateral hypogastric (n = 9), sham-hypogastric (n = 3), pelvic (n = 3), or pudendal (n = 2) neurectomies. As predicted, sham-hypogastric, pelvic, and pudendal neurectomies had no effect on the rats' responses. However, although hypogastric neurectomy completely eliminated responses in five rats whose postmortem evaluation revealed no signs that the uterine balloons had evoked any pelvic pathophysiology, the neurectomy had no effect on the responses of an additional four rats. Postmortem evaluation of these rats revealed gross signs of severe pathology in the vicinity of the balloon in two rats, and evidence that the balloon had shifted caudally so that it was stimulating the cervix rather than the uterine horn in a third. In the fourth rat, pathophysiology had been deliberately induced by the prior implantation of a small pellet that released approximately 1 microg/day of prostaglandin PF2alpha over the uterine horn. Similar findings have been reported in clinical studies on the efficacy of hypogastric ('presacral') neurectomy for dysmenorrhea. Together, the findings support the hypothesis that the major source of afferent innervation of the uterine horn in healthy rats and women is the hypogastric nerve but that the situation changes under conditions of pelvic pathology. Such changes could include additional activation of afferent fibers in nerves that supply other pelvic organs, activation by the uterine pathophysiology of latent uterine innervation from afferent fibers in the pelvic, vagus or ovarian plexus nerves, or some form of central sensitization.

Effects of antibodies to transferrin and alpha 2-HS glycoprotein on in vitro sperm motion: implications in infertility associated with endometriosis

PROBLEM

Women with endometriosis have antibodies to endometrial transferrin and alpha 2-HS glycoprotein in their serum and peritoneal fluid. The objective of this study was to determine whether antibodies to transferrin and alpha 2-HS glycoprotein adversely affect sperm motility and survival.

METHOD OF STUDY

Spermatozoa obtained from normal fertile donors and washed free of seminal plasma were incubated with the medium (control), 1:2 and 1:100 dilutions of antitransferrin, 1:4, 1:8 and 1:100 dilutions of anti-alpha 2-HS glycoprotein, and a 1:2 dilution of antialbumin antiserum (negative control). Sperm motion characteristics in 10 microliters aliquots were evaluated at 30 min, 1 hr, 2 hr, 4 hr, and 24 hr using computerized sperm motion analysis. A paired t-test was done to analyze the effects of the various antibodies on sperm motion characteristics.

RESULTS

Antibodies to albumin failed to adversely affect sperm motility in general or the several sperm motion characteristics in particular. In contrast, antibodies to transferrin at the dilution of 1:2 adversely affected the percentage of motile and rapid spermatozoa, progressive and path velocities, straightness, linearity, track speed, and anterior-lateral head displacement (P < 0.001) at all the time intervals, whereas a 1:100 dilution of this antiserum adversely affected these parameters only at 24 hr. Elongation and beat cross-frequency were significantly affected at 4 and 24 hr by a 1:2 dilution of antitransferrin antiserum. The effects of anti-alpha 2-HS glycoprotein were more pronounced than those of antitransferrin, but they were similar. Dilutions of 1:4 and 1:8 were effective at all time intervals, whereas a 1:100 dilution was effective in reducing the track speed and the percentage of rapid cells at 24 hr (P < 0.001).

CONCLUSION

Antibodies to endometrial transferrin and alpha 2-HS glycoprotein present in the peritoneal fluid, and possibly in the oviductal fluid, of patients with endometriosis may adversely affect postcoital sperm motility and sperm survival.

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.

T-helper 2 type cytokine and soluble interleukin-2 receptor levels in seminal plasma of infertile men

PROBLEM

The role of cell-mediated immunity (CMI) in unexplained male infertility and impaired sperm function has been explored.

METHOD OF STUDY

The presence of cytokines, namely, interleukin-4 (IL-4), interleukin-6 (IL-6), and the soluble interleukin-2 receptor (SIL-2R), was investigated in seminal plasma of 18 fertile and 20 infertile subjects, using specific enzyme-linked immunoadsorbent assays.

RESULTS

IL-4 was not detected. SIL-2R was detected, but the concentration difference between the fertile and infertile group was not significant. IL-6 was detected with significantly higher levels in the infertile group compared to the fertile group. IL-6 levels in seminal plasma correlated positively with leukocyte count and negatively with sperm count, motility, and morphology.

CONCLUSIONS

These findings show: a) a lack of IL-4 in seminal plasma; b) similar SIL-2R levels in fertile and infertile seminal plasma; c) increased IL-6 secretion in seminal plasma of infertile subjects; and d) specific correlations of IL-6 with the main semen parameters.

Elevated serum lipoprotein(a) levels in young women with endometriosis

Elevated serum lipoprotein(a) [Lp(a)] levels increase the risk of cardiovascular disease if levels of low-density lipoproteins (LDLs) are also high. The biological function of Lp(a) is unknown, but plasma levels may be elevated in inflammatory disease. Endometriosis is a common gynecologic disorder in which endometrial tissue is found outside of the lining of the uterine cavity. There is an immune component to this condition whereby the number of peritoneal macrophages is increased and the level of prostanoids and cytokines in peritoneal fluid is elevated. In the present study, we measured serum lipid, lipoprotein, and apolipoprotein levels in 29 women with endometriosis and in 29 matched healthy controls. Fasting serum triglyceride and apolipoprotein (apo) Al levels were higher in women with endometriosis (+28.1%, P < .001, and +12.3%, P < .01, respectively), but there were no significant differences in LDL or high-density lipoprotein (HDL) cholesterol levels. Serum Lp(a) levels were fivefold higher (P < .01) in the patients (median, 15.0 mg/dL; range, 0.05 to 60.0) than in controls (median, 3.1 mg/dL; range, 0.05 to 57.2). The distribution of apo(a) isoforms was similar in the two groups, but in women with endometriosis the individual apo(a) isoforms tended to be associated with higher serum Lp(a) levels. Endometriosis may represent a relatively common condition in which to investigate the role of Lp(a) in human metabolism.

Immunology and endometriosis. Fact, artifact, or epiphenomenon?

Endometriosis is a complex and intriguing disease. If retrograde menstruation normally occurs, then why do all women not develop endometriosis? The exact prevalence of endometriosis is unknown; however, a 20% to 90% prevalency rate has been reported in women with pelvic pain and infertility. This article reviews the factors involved.

Endometriosis and infertility: new concepts

Endometriosis is a common gynecological disorder with varied symptomatology including chronic pelvic pain, dysmenorrhea, and infertility. The association of endometriosis and infertility has been recognized for years, although definite evidence of causality still eludes us. In this review, we will explore three general concepts that enhance our understanding of the cellular and molecular interactions contributing to the pathophysiology of this disorder and that have steered current research in endometriosis. First, we review evidence of a local peritoneal inflammatory process, supported by the findings of elevated cytokine and growth factor concentrations in peritoneal fluid of affected patients. Second, we propose a role for angiogenic factors in the establishment of ectopic implants. Third, we review evidence for biochemical differences of eutopic and ectopic endometrium in endometriosis patients, which may contribute to both the pathogenesis and sequelae of this important disorder. Through information derived from these research efforts, we hope to develop better therapeutic interventions as adjunctive or alternative therapies to our current medical and surgical armamentarium.