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

Molecular Mechanisms of Endometriosis Revealed Using Omics Data

Endometriosis is a gynecological disorder prevalent in women of reproductive age. The primary symptoms include dysmenorrhea, irregular menstruation, and infertility. However, the pathogenesis of endometriosis remains unclear. With the advent of high-throughput technologies, various omics experiments have been conducted to identify genes related to the pathophysiology of endometriosis. This review highlights the molecular mechanisms underlying endometriosis using omics. When genes identified in omics experiments were compared with endometriosis disease genes identified in independent studies, the number of overlapping genes was moderate. However, the characteristics of these genes were found to be equivalent when functional gene set enrichment analysis was performed using gene ontology and biological pathway information. These findings indicate that omics technology provides invaluable information regarding the pathophysiology of endometriosis. Moreover, the functional characteristics revealed using enrichment analysis provide important clues for discovering endometriosis disease genes in future research.

Peritoneal immune microenvironment of endometriosis: Role and therapeutic perspectives

Endometriosis, an estrogen-dependent chronic inflammatory disease characterized by the growth of endometrium-like tissues outside the uterine cavity, affects 10% of reproductive-age women. Although the pathogenesis of endometriosis is uncertain, it is widely accepted that retrograde menstruation results in ectopic endometrial tissue implantation. Given that not all women with retrograde menstruation develop endometriosis, immune factors have been hypothesized to affect the pathogenesis of endometriosis. In this review, we demonstrate that the peritoneal immune microenvironment, including innate immunity and adaptive immunity, plays a central role in the pathogenesis of endometriosis. Current evidence supports the fact that immune cells, such as macrophages, natural killer (NK) cells, dendritic cells (DCs), neutrophils, T cells, and B cells, as well as cytokines and inflammatory mediators, contribute to the vascularization and fibrogenesis of endometriotic lesions, accelerating the implantation and development of ectopic endometrial lesions. Endocrine system dysfunction influences the immune microenvironment through overexpressed estrogen and progesterone resistance. In light of the limitations of hormonal therapy, we describe the prospects for potential diagnostic biomarkers and nonhormonal therapy based on the regulation of the immune microenvironment. Further studies are warranted to explore the available diagnostic biomarkers and immunological therapeutic strategies for endometriosis.

Computational Drug Discovery in Patients with Endometriosis-Induced Infertility via Text Mining and Biomedical Databases

Background: Endometriosis (EMT) is the most common benign gynecological disease among women of reproductive age, causing infertility and seriously affects women’s physical and mental health. However, the current treatment was not always effective. This study was designed to use publicly available data to identify drugs targeting the relevant gene with EMT-induced-infertility using computational tools. Methods: EMT and infertility genes were determined by text mining, and the GeneCodis program was used to analyzed gene ontology of the intersection of the two gene sets. A string database was used to analyze the protein-protein interaction network. The Drug-Gene Interaction database is queried for the rich gene set belonging to the identified pathways to find drug candidates that can be used in EMT-induced infertility. Results: Our analysis identified 550 genes common to both the EMT and infertility by text mining. Gene enrichment analysis and protein-protein interaction analysis found 39 genes potentially targetable by a total of 49 drugs that could be formulated for application, which have not been used in EMT-induced infertility. Conclusions: The findings from the present analysis can facilitate the Identification of existing drugs that have the potential of topical administration to improve EMT-induced infertility and present tremendous opportunities to study novel targets pharmacology using in silico text mining and pathway analysis tools. However, all the results were based on online bioinformatics databases, and as such require validation experiments. And some of the drugs highlighted as possibly relevant may be toxic and as such safely data is required before any experiments are undertaken in humans.

The role of the Immune System in the Development of Endometriosis

Endometriosis is a chronic disease that affects about 10% of women of reproductive age. It can contribute to pelvic pain, infertility or other conditions such as asthma, cardiovascular disease, breast or ovarian cancer. Research has shown that one of the conditions for the development of endometrial lesions is the dysfunction of the immune system. It appears that immune cells, such as neutrophils, macrophages, NK cells and dendritic cells, may play a specific role in the angiogenesis, growth and invasion of endometriosis cells. Immune cells secrete cytokines and defensins that also affect the endometriosis environment. This review discusses the various components of the immune system that are involved in the formation of endometrial lesions in women.

Endometrial macrophages in health and disease

Macrophages are present in the endometrium throughout the menstrual cycle and are most abundant during menstruation. Endometrial macrophages contribute to tissue remodeling during establishment of pregnancy and are thought to play key roles in mediating tissue breakdown and repair during menstruation. Despite these important roles, the phenotype and function of endometrial macrophages remains poorly understood. In this review, we summarize approaches used to characterize endometrial macrophage phenotype, current understanding of the functional role of macrophages in normal endometrial physiology as well as the putative contribution of macrophage dysfunction to women's reproductive health disorders.

Iron Therapeutics in Women's Health: Past, Present, and Future

Iron plays a unique physiological role in the maintenance of homeostasis and the pathological outcomes of the female reproductive tract. The dual nature of elemental iron has created an evolutionary need to tightly regulate its biological concentration. The female reproductive tract is particularly unique due to the constant cycle of endometrial growth and shedding, in addition to the potential need for iron transfer to a developing fetus. Here, iron regulation is explored in a number of physiologic states including the endometrial lining and placenta. While iron dysregulation is a common characteristic in many women's health pathologies there is currently a lack of targeted therapeutic options. Traditional iron therapies, including iron replacement and chelation, are common treatment options for gynecological diseases but pose long term negative health consequences; therefore, more targeted interventions directed towards iron regulation have been proposed. Recent findings show potential benefits in a therapeutic focus on ferritin-hepcidin regulation, modulation of reactive oxygen species (ROS), and iron mediated cell death (ferroptosis). These novel therapeutics are the direct result of previous research in iron's complex signaling pathway and show promise for improved therapy, diagnosis, and prognosis in women's health.

Anti-IL-6 receptor monoclonal antibody as a new treatment of endometriosis

Many pro-inflammatory cytokines especially tumor necrotic factor alpha (TNFα), interleukin (IL)-1β, and IL-6 have crucial role in the pathogenesis of endometriosis. In this study, we investigated the immune-modulatory role of humanized anti-IL-6 receptor monoclonal antibodies in the treatment of endometriosis. This is a prospective, randomized, controlled, blinded study in which Sprague Dawley rats were used as animal model of endometriosis. Animals were randomly divided into two groups, a test group which received tocilizumab (Actemra; Roche, Switzerland) and a control group which received saline. Afterwards, a comparison was done between the eutopic and ectopic endometrium that was excised from both groups, histopathologically and immune-histochemically. Histopathologic assessment and immune-histochemical staining were performed using antibodies against IL-6. Tocilizumab significantly suppressed the volume of endometriotic lesions compared with non-treated rats (P = 0.006) and atrophied the ectopic endometrial-like epithelium (in 42.8% of treated rats vs 0% in the control group). Tocilizumab also decreased the anti-IL-6 receptor immune-histochemical staining intensity in ectopic endometrium (from non to +++ in the test group vs ++ or more in the control group), with no apparent difference in the eutopic one reflecting the down-regulation of IL-6-producing cells in ectopic endometriotic lesions. In rats with induced endometriosis, anti-IL-6 receptor monoclonal antibodies could offer a new horizon of usage of this immune-modulatory biologic drug, used in other autoimmune diseases, in treatment of endometriosis.

Caulis Sargentodoxae Prescription Plays a Therapeutic Role with Decreased Inflammatory Cytokines in Peritoneal Fluid in the Rat Endometriosis Model

Caulis Sargentodoxae prescription has been confirmed by the gynecological clinical observation to be effective in the treatment of endometriosis (EMs), and inflammatory cytokines were involved in EMs. In this paper, animal experiments were designed to explain anti-inflammatory mechanisms of Caulis Sargentodoxae prescription on endometriosis. The EMs model was established by autoplastic transplantation, and rats were randomly divided into seven groups: normal control group, model group, ovariectomized group, gestrinone (Western medicine) group, Caulis Sargentodoxae prescription (Chinese medicine) group, celecoxib (inhibitor) group, and combination (Chinese medicine + inhibitor) group. After oral administration for 21 days, the growth inhibitory rates of the ectopic endometria in treatment groups were evaluated, and the levels of inflammatory cytokines in the serum and peritoneal fluid were determined by ELISA, as well as the expression of prostaglandin endoperoxide synthase 2 (PTGS2) in the ectopic endometrial tissues was detected by real-time polymerase chain reaction, immunohistochemistry, and western blotting. The growth inhibitory rates of the ectopic endometria were significantly higher in the Caulis Sargentodoxae prescription group and gestrinone group, in comparison with the model group (p < 0.05). In the Caulis Sargentodoxae prescription group, the levels of inflammatory cytokines including IL-1, IL-2, IL-6, TNF-α, and PGE2 were all reduced in the serum and peritoneal fluid (p < 0.05). In addition, the specific expression of PTGS2 in the ectopic endometrial tissues significantly decreased in the Caulis Sargentodoxae prescription group and PTGS2 inhibitor celecoxib group both at mRNA and protein levels, but in the steroid hormone drug gestrinone group not at the mRNA level. So, Caulis Sargentodoxae prescription has a reliable therapeutic effect on the EMs by its comprehensive anti-inflammatory roles, possibly in a way different from gestrinone.

Recent advances in mammalian reproductive biology

Reproductive biology is a uniquely important topic since it is about germ cells, which are central for transmitting genetic information from generation to generation. In this review, we discuss recent advances in mammalian germ cell development, including preimplantation development, fetal germ cell development and postnatal development of oocytes and sperm. We also discuss the etiologies of female and male infertility and describe the emerging technologies for studying reproductive biology such as gene editing and single-cell technologies.

Identifying Mechanisms of Endometriosis-Associated Reduced Fecundity in a Rat Model: Novel Insights toward Understanding Human Infertility

The existence of endometriosis has been known since at least the nineteenth century, yet the lack of understanding of causes of infertility and therefore inadequate treatment approaches in endometriosis creates a significant challenge in reproductive medicine. Women worldwide suffer not only pain and infertility but also economical, societal, and physiological burdens. Studies of reproductive events in women are difficult to conduct due to a host of confounding personal and environmental factors and ethically limited due to the very nature of working with reproductive tissues and cells, especially embryos. Animal models are a viable adjunct to study mechanisms causing human reproductive anomalies and infertility in endometriosis. This chapter discusses reproductive anomalies causing infertility in endometriosis and well-established animal models which help decipher the problems and lead to heretofore unknown nonsurgical, nonhormonal methods to manage endometriosis in women. In addition, studies of effects of developmental exposure to endometriosis are revealing for the first time, in both female and male offspring, transgenerational subfertility in a rat model providing insights into the familial nature of endometriosis and possible epigenetic involvement.

Designation of fingerprint glycopeptides for targeted glycoproteomic analysis of serum haptoglobin: insights into gastric cancer biomarker discovery

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide, largely because of difficulties in early diagnosis. Despite accumulating evidence indicating that aberrant glycosylation is associated with GC, site-specific localization of the glycosylation to increase specificity and sensitivity for clinical use is still an analytical challenge. Here, we created an analytical platform with a targeted glycoproteomic approach for GC biomarker discovery. Unlike the conventional glycomic approach with untargeted mass spectrometric profiling of released glycan, our platform is characterized by three key features: it is a target-protein-specific, glycosylation-site-specific, and structure-specific platform with a one-shot enzyme reaction. Serum haptoglobin enriched by immunoaffinity chromatography was subjected to multispecific proteolysis to generate site-specific glycopeptides and to investigate the macroheterogeneity and microheterogeneity. Glycopeptides were identified and quantified by nano liquid chromatography-mass spectrometry and nano liquid chromatography-tandem mass spectrometry. Ninety-six glycopeptides, each corresponding to a unique glycan/glycosite pairing, were tracked across all cancer and control samples. Differences in abundance between the two groups were marked by particularly high magnitudes. Three glycopeptides exhibited exceptionally high control-to-cancer fold changes along with receiver operating characteristic curve areas of 1.0, indicating perfect discrimination between the two groups. From the results taken together, our platform, which provides biological information as well as high sensitivity and reproducibility, may be useful for GC biomarker discovery. Graphical abstract ᅟ.

Role of Interleukin-6 and Its Receptor in Endometriosis

Background

Studies have shown that the concentration of interleukin (IL)-6 in peritoneal fluid is increased in patients with endometriosis; however, whether the disorders involving IL-6 contribute to the development of endometriosis is still unclear. In the present study, we evaluated the potential role of IL-6 and IL-6 receptor (IL-6R) in the pathogenesis of endometriosis.

Material/Methods

We examined activated macrophages and the expression of membrane-binding receptor (mIL-6R) in peritoneal fluid using flow cytometry. The levels of IL-6 and the IL-6 soluble receptor (sIL-6R) in peritoneal fluid and plasma in patients with endometriosis was measured by an enzyme-linked immunosorbent assay.

Results

Activated macrophages and mIL-6R in peritoneal fluid were increased in patients with endometriosis. IL-6 and sIL-6R in peritoneal fluid were also increased in patients with endometriosis; however, there was an increase in plasma IL-6 and a decrease in plasma sIL-6R. The endometriosis group was categorized into 2 groups according to the retrospective American Fertility Society Score (r-AFS): group A and group B. Peritoneal fluid sIL-6R in endometriosis group B was significantly higher than in endometriosis group A and the control group.

Conclusions

Disorders involving IL-6 and IL-6R are correlated with the etiology of endometriosis. An increase in sIL-6R in peritoneal fluid promotes the development of endometriosis by enhancing the bioactivity of IL-6.

Endometriosis and Infertility: A Systematic Review

Endometriosis is one of the most common gynaecological conditions affecting 6% to 12% of women in the reproductive age group. It can be found in 35% to 45% of women who are trying to conceive and are infertile. Infertility is one of the most common problems associated with endometriosis. This review will look at the evidence that endometriosis may lead to infertility and the data looking at whether surgical correction of endometriosis may improve fertility outcomes.

Potential scenarios leading to ovarian cancer arising from endometriosis

OBJECTIVES

The aim of this review was to highlight recent advances in our understanding of the pathogenesis of malignant transformation of endometriosis.

METHODS

This study reviewed the English-language literature concerning basic science studies of the potential promotion of carcinogenesis.

RESULTS

Repeated episodes of hemorrhage occur in endometriosis at the onset of menstruation. Extracellular hemoglobin, heme, and iron derivatives in endometriosis cause DNA damage and mutations, which create increased cellular susceptibility to oxidant-mediated cell killing. Excess DNA damage and mutations are linked to cell death, but not carcinogenesis. In response to an oxidative and inflammatory microenvironment, endometriotic cells and macrophages secrete antioxidants that control excess oxidative stress in the surrounding environment. Exposure of endometriotic cells to a sublethal level of oxidative stress may lead to carcinogenesis. Macrophages also secrete immunosuppressive factors that lead to promotion of malignant transformation.

DISCUSSION

At least two potential scenarios could result in ovarian cancer arising from endometriosis. The first step: extracellular hemoglobin, heme, and iron cause cellular oxidative damage by promoting reactive oxygen species formation, which results in DNA damage and mutations (ovarian cancer initiation from endometriosis). The second step: cancer progression may be associated with persistent antioxidant production favoring a protumoral microenvironment.

Challenges in the development of novel therapeutic strategies for treatment of endometriosis

INTRODUCTION

Endometriosis is an estrogen-dependent disease that results in pelvic pain and infertility. Its treatment is often frustrating due to limited medical treatment options, complex surgical treatment and high recurrence rates. Despite the advances in our understanding of the pathogenesis over the last decades and the consequent novel therapeutic strategies, no new drugs have been introduced in daily clinical practice.

AREAS COVERED

In the first part we present an overview of the pathogenesis of endometriosis. In the second part we discuss how new insights have led to the development of novel nonhormonal strategies for the treatment of endometriosis, focusing on anti-inflammatory and anti-angiogenic agents. In the third part we describe the problems encountered in the translation from experimental drugs to routine medicine for the treatment of endometriosis.

EXPERT OPINION

Despite the multitude of agents that have been tested in preclinical trials, only few drugs have passed to the stage of clinical testing and none have been introduced into clinical practice. It is our opinion that the major challenges in the translation from novel agents for endometriosis is due to the use of inadequate rodent models and a lack of standardization in the design and reporting of preclinical endometriosis models.

Contrast-Enhanced Sonographic Features Before and After Interventional Treatment of Ovarian Endometrial Cysts

OBJECTIVES

The purpose of this study was to assess contrast-enhanced sonography features before and after interventional treatment of ovarian endometrial cysts.

METHODS

We retrospectively analyzed 53 patients with ovarian endometrial cysts who underwent contrast-enhanced sonography before and after interventional treatment to assess the sonographic features of the cysts at these different times. The sonographic features and quantitative parameters for the cysts were compared before and after treatment.

RESULTS

The wash-in mode showed rapid annular enhancement of the cyst wall and slow wash-out with even and uneven enhancement types. Compared to the internal iliac artery, the enhancement intensity was weaker, and the wash-in and wash-out times were longer in the cyst wall; furthermore, all 5 quantitative parameters differed between the cyst wall and internal iliac artery. The wash-in and wash-out characteristics of the cysts before and after interventional treatment were almost identical. The enhancement was primarily even before treatment and uneven after treatment; the enhancement intensity was low in all cases. Although the wash-in time before and after treatment did not differ, the wash-out time for the cysts before treatment was significantly lower than that observed after treatment. Two quantitative parameters differed before and after treatment.

CONCLUSIONS

The contrast-enhanced sonographic features and quantitative parameters for the walls of ovarian endometrial cysts differed before and after ultrasound-guided interventional treatment. These characteristics could be valuable for evaluating the efficacy of interventional treatment of ovarian endometrial cysts.

Role of the CXCL12-CXCR4 axis in the development of deep rectal endometriosis

Immunological and angiogenetic factors enhance the implantation of endometrial cells in the peritoneal cavity. The aim of this work was to determine the role of the CXCL12-CXCR4 axis in the attraction and the peritoneal implantation of endometriotic stromal cells in deep infiltrating endometriosis (DIE). Biopsies of DIE nodules were obtained from 14 patients undergoing surgical treatment for DIE with low rectal involvement and from 12 patients without macroscopic endometriosis undergoing laparoscopy. CXCR4 expression was evaluated by Western blot analysis and flow cytometry in eutopic endometrial cells and DIE stromal cells in primary cultures derived from the biopsies. CXCL12-induced migration of DIE eutopic endometrial stromal cells was evaluated by transwell migration. CXCL12 was assayed in peritoneal fluids by ELISA. CXCR4 expression was higher in eutopic endometrial stromal cells than in control endometrial cells (p<0.05) and in DIE stromal cells (p<0.05). Eutopic endometrial stromal cells were more attracted by CXCL12 than control cells (p<0.01). CXCL12 was higher in DIE peritoneal fluids than in controls (p<0.05). CXCR4 was down-regulated in deep infiltrating endometriotic stromal cells. The CXCL12-CXCR4 axis plays a role in the attraction of eutopic endometrial cells into the peritoneal cavity, and the down-regulation of CXCR4 in resident endometriotic cells could cause their arrest in situ.

Biomarkers of endometriosis

BACKGROUND

Diagnosis of endometriosis is surgical through laparoscopy, which is invasive, costly and associated with potential complications.

OBJECTIVES

A non-invasive test for diagnosis of endometriosis will focus the use of laparoscopy on women who are highly suspected of having endometriosis. This review includes studies about different biomarkers for endometriosis and their potential for the non-surgical diagnosis of this disease.

METHODS

This review covers studies that investigated different biomarkers in blood or endometrium. Studies that identified definite cutoff points and evaluated the diagnostic performance of the biomarker as a blood test for endometriosis are focused on.

RESULTS/CONCLUSIONS

Some of the markers investigated showed a good specificity, none of them showed a high sensitivity. More multi-center studies involving larger numbers of patients are required to identify the most useful biomarker.

Cellular and molecular basis for endometriosis-associated infertility

Endometriosis is a gynecological disease characterized by the presence of endometrial glandular epithelial and stromal cells growing in the extra-uterine environment. The disease afflicts 10%–15% of menstruating women causing debilitating pain and infertility. Endometriosis appears to affect every part of a woman’s reproductive system including ovarian function, oocyte quality, embryo development and implantation, uterine function and the endocrine system choreographing the reproductive process and results in infertility or spontaneous pregnancy loss. Current treatments are laden with menopausal-like side effects and many cause cessation or chemical alteration of the reproductive cycle, neither of which is conducive to achieving a pregnancy. However, despite the prevalence, physical and psychological tolls and health care costs, a cure for endometriosis has not yet been found. We hypothesize that endometriosis causes infertility via multifaceted mechanisms that are intricately interwoven thereby contributing to our lack of understanding of this disease process. Identifying and understanding the cellular and molecular mechanisms responsible for endometriosis-associated infertility might help unravel the confounding multiplicities of infertility and provide insights into novel therapeutic approaches and potentially curative treatments for endometriosis.

Two-dimensional gel electrophoresis in peritoneal fluid samples identifies differential protein regulation in patients suffering from peritoneal or ovarian endometriosis

Endometriosis is determined by local and systemic proinflammatory dysregulation and therefore differential protein expression in peritoneal fluid (PF). Of highest interest is lesion formation and the establishment and persistence of endometriosis. In this study we analyzed well-characterized PF samples of patients with ovarian or peritoneal endometriosis and compared them to control samples. We found 11 proteins differentially regulated, of which some might play a key role in the pathogenesis of endometriosis.

Proteolytic tailoring of the heat shock protein 70 and its implications in the pathogenesis of endometriosis

OBJECTIVE

To investigate the mechanism underlying the appearance of a 20-kd HSP70 fragment and its consequences in the ectopic endometrium of endometriosis patients.

DESIGN

Experimental study.

SETTING

Research institute and obstetrics and gynecology clinic.

PATIENT(S)

Participants with (n = 18) and without (n = 20) endometriosis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Reverse-transcription polymerase chain reaction, protease assays, and in silico tools were used to investigate the origin of the 20-kd HSP70 fragment. Immunocolocalization studies were carried out to determine whether subtilisin/kexin isozyme 1 (SKI-1) and HSP70 are colocalized. Expression and localization of surrogate markers of inflammation, such as nuclear factor NF-κB and interleukin IL-6 were examined by immunoblotting and in situ studies.

RESULT(S)

HSP70 is posttranslationally processed into a 20-kd fragment by SKI-1, a protease of the subtilisin family, in ectopic endometrium (ECE). Immunocolocalization studies revealed spatial proximity of SKI-1 and HSP70 in ECE. Furthermore, ECE demonstrated nuclear localization of the transcription factor, NF-κB and high expression of its target protein, IL-6.

CONCLUSION(S)

This study hints at the possible mechanisms underlying the trimming of HSP70 in ECE and also at the role of proteases in the pathogenesis of endometriosis. The possible repercussions of HSP70 fragmentation include dysregulation of key regulatory proteins, resulting in the escalation of inflammatory events in endometriotic lesions.

Identification of plasma haptoglobin forms which loosely bind hemoglobin

Haptoglobin (Hpt) is known to capture circulating free hemoglobin (Hb) and bind apolipoprotein (Apo) A-I or E. Here, we report that Hb can be tightly bound by most of Hpt molecules (TB-Hpt, 80%), whereas loosely bound by a minor part of them (LB-Hpt, 20%). LB-Hpt amount was significantly increased (over 60%) in patients with acute coronary syndrome. LB-Hpt bound ApoA-I and ApoE less efficiently than TB-Hpt (8- and 4-fold less, respectively) and did not affect their activity of stimulating the enzyme lecithin-cholesterol acyltransferase. LB-Hpt and TB-Hpt displayed comparable levels of nitrotyrosine residues, but differences in glycan chains. Changes in LB-Hpt level might be associated with changes in Hpt functions.

Gene expression changes associated with resistance to intravenous corticosteroid therapy in children with severe ulcerative colitis

BACKGROUND AND AIMS

Microarray analysis of RNA expression allows gross examination of pathways operative in inflammation. We aimed to determine whether genes expressed in whole blood early following initiation of intravenous corticosteroid treatment can be associated with response.

METHODS

From a prospectively accrued cohort of 128 pediatric patients hospitalized for intravenous corticosteroid treatment of severe UC, we selected for analysis 20 corticosteroid responsive (hospital discharge or PUCAI ≤45 by day 5) and 20 corticosteroid resistant patients (need for second line medical therapy or colectomy, or PUCAI >45 by day 5). Total RNA was extracted from blood samples collected on day 3 of intravenous corticosteroid therapy. The eluted transcriptomes were quantified on Affymetrix Human Gene 1.0 ST arrays. The data was analysed by the local-pooled error method for discovery of differential gene expression and false discovery rate correction was applied to adjust for multiple comparisons.

RESULTS

A total of 41 genes differentially expressed between responders and non-responders were detected with statistical significance. Two of these genes, CEACAM1 and MMP8, possibly inhibited by methylprednisolone through IL8, were both found to be over-expressed in non-responsive patients. ABCC4 (MRP4) as a member of the multi-drug resistance superfamily was a novel candidate gene for corticosteroid resistance. The expression pattern of a cluster of 10 genes selected from the 41 significant hits were able to classify the patients with 80% sensitivity and 80% specificity.

CONCLUSIONS

Elevated expression of several genes involved in inflammatory pathways was associated with resistance to intravenous corticosteroid therapy early in the course of treatment. Gene expression profiles may be useful to classify resistance to intravenous corticosteroids in children with severe UC and assist with clinical management decisions.

Endometriosis and infertility: pathophysiology and management

Endometriosis and infertility are associated clinically. Medical and surgical treatments for endometriosis have different effects on a woman's chances of conception, either spontaneously or via assisted reproductive technologies (ART). Medical treatments for endometriosis are contraceptive. Data, mostly uncontrolled, indicate that surgery at any stage of endometriosis enhances the chances of natural conception. Criteria for non-removal of endometriomas are: bilateral cysts, history of past surgery, and altered ovarian reserve. Fears that surgery can alter ovarian function that is already compromised sparked a rule of no surgery before ART. Exceptions to this guidance are pain, hydrosalpinges, and very large endometriomas. Medical treatment-eg, 3-6 months of gonadotropin-releasing hormone analogues-improves the outcome of ART. When age, ovarian reserve, and male and tubal status permit, surgery should be considered immediately so that time is dedicated to attempts to conceive naturally. In other cases, the preference is for administration of gonadotropin-releasing hormone analogues before ART, and no surgery beforehand. The strategy of early surgery, however, seems counterintuitive because of beliefs that milder non-surgical options should be offered first and surgery last (only if initial treatment attempts fail). Weighing up the relative advantages of surgery, medical treatment and ART are the foundations for a global approach to infertility associated with endometriosis.

Inflammatory cytokines differentially up-regulate human endometrial haptoglobin production in women with endometriosis

BACKGROUND

Evidence suggests that eutopic endometrium from women with endometriosis (US-E) has intrinsic functional anomalies compared with women without endometriosis (US-C). We hypothesized that differences in endometrial haptoglobin (eHp) mRNA and protein levels exist between eutopic endometrium from US-E and US-C and that inflammatory mediators may be involved.

METHODS

Endometrial stromal cells and tissue explants from US-E (n = 18) and US-C (n = 18) were cultured (24 h/48 h for cells/explants) with interleukin (IL)-1alpha, -1beta, -6, -8 or tumor necrosis factor-alpha (TNF-alpha) at 0-100 ng/ml. eHp protein in media and mRNA levels were quantified by enzyme-linked immunosorbent assay and quantitative PCR.

RESULTS

In eutopic endometrial stromal cells from US-E, IL-1beta, IL-6 and TNF-alpha (10 ng/ml) increased eHp mRNA levels (P = 0.002, P < 0.001 and P < 0.001, respectively) and eHp protein (P = 0.023, 0.031 and 0.006, respectively) versus control. In endometrial tissues from US-E, IL-1beta, IL-6 and TNF-alpha increased eHp mRNA (P < 0.001, P = 0.017 and P < 0.001, respectively) and eHp protein (P < 0.001, P = 0.007 and 0.039, respectively) versus control. IL-1alpha and IL-8 had small or no effects on isolated endometrial cells or tissues. In US-C, IL-1beta, IL-8 and TNF-alpha each reduced eHp mRNA in endometrial stromal cells (all P < 0.001) versus control; IL-1alpha and IL-6 had no effect. eHp mRNA increased in endometrial tissues from US-C in response to IL-1beta (P = 0.008), IL-6 (P = 0.015) and TNF-alpha (P = 0.031) versus control; IL-1alpha or IL-8 had no effect.

CONCLUSIONS

Endometrium from US-E differentially responds to specific inflammatory cytokines by production of eHp. We propose that up-regulation of endometrial eHp by inflammatory mediators disrupts normal endometrial function and may facilitate the pathogenesis of endometriosis.

Aberrant gene expression profile in a mouse model of endometriosis mirrors that observed in women

OBJECTIVE

To define the altered gene expression profile of endometriotic lesions in a mouse model of surgically induced endometriosis.

DESIGN

Autologous experimental mouse model.

SETTING

Medical school department.

ANIMAL(S)

Adult C57Bl6 mice.

INTERVENTION(S)

Endometriosis was surgically induced by autotransplantation of uterine tissue to the intestinal mesentery. Endometriotic lesions and eutopic uteri were recovered at 3 or 29 days after induction.

MAIN OUTCOME MEASURE(S)

Altered gene expression was measured in the endometriotic lesion relative to the eutopic uterus by genome-wide complementary DNA microarray analysis and was confirmed by real-time reverse transcriptase-polymerase chain reaction for six genes. Relevant categories of altered genes were identified using gene ontology analysis to determine groups of genes enriched for altered expression.

RESULT(S)

The expression of 479 and 114 genes was altered in the endometriotic lesion compared with the eutopic uterus at 3 or 29 days after induction, respectively. Gene ontology enrichment analysis revealed that genes associated with the extracellular matrix, cell adhesions, immune function, cell growth, and angiogenesis were altered in the endometriotic lesion compared with the eutopic uterus.

CONCLUSION(S)

According to gene expression analysis, the mouse model of surgically induced endometriosis is a good model for studying the pathophysiology and treatment of endometriosis.

Haptoglobin expression in endometrioid adenocarcinoma of the uterus

OBJECTIVE

Elevated serum haptoglobin (Hp) concentrations have been reported in patients with malignant diseases. We have shown that Hp is produced by and localizes only in the stroma and not the epithelium of endometriotic lesions, which share many characteristics of carcinoma. Furthermore, Hp mRNA and protein are found exclusively in the stroma of eutopic endometrium from women with endometriosis and not those without endometriosis. We hypothesized that characteristic patterns of Hp gene expression and protein localization in endometrioid adenocarcinoma of the uterus may provide insight into the clinical utility of Hp as a tumor marker or alternative therapeutic approach.

METHODS

Biopsies of endometrioid adenocarcinoma tumors of the uterus and their adjacent nonaffected endometrium were collected. Normal endometrium was collected from healthy women. Haptoglobin messenger RNA (mRNA) levels were quantified by quantitative polymerase chain reaction (Q-PCR). Haptoglobin protein cell-specific localization was identified by immunohistochemistry.

RESULTS

Haptoglobin mRNA levels were significantly greater (P < .005) in endometrioid adenocarcinoma and adjacent nonaffected endometrial tissues than normal endometrium. No correlation was found between Hp levels and cancer stage (P = .673) or grade (P = .739). Haptoglobin protein localized in both stromal and glandular epithelial cells of endometrioid adenocarcinoma and their adjacent nonaffected tissue but not in control endometrium.

CONCLUSIONS

Our results have identified, for the first time, unique patterns of Hp mRNA expression and protein localization in the stromal and glandular epithelial cells of endometrioid adenocarcinoma of the uterus. We propose that this unique pattern of endometrioid adenocarcinoma Hp expression may be developed as a novel diagnostic marker. Modulation of Hp, with its immunomodulatory and angiogenic properties, may generate novel methods of prevention or treatment for endometrial cancer.

Intraperitoneal inflammation decreases endometriosis in a mouse model

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Neuroendocrine-immune disequilibrium and endometriosis: an interdisciplinary approach

Endometriosis, a chronic disease characterized by endometrial tissue located outside the uterine cavity, affects one fourth of young women and is associated with chronic pelvic pain and infertility. However, an in-depth understanding of the pathophysiology and effective treatment strategies of endometriosis is still largely elusive. Inadequate immune and neuroendocrine responses are significantly involved in the pathophysiology of endometriosis, and key findings are summarized in the present review. We discuss here the role of different immune mechanisms particularly adhesion molecules, proteinglycan interactions, and pro-angiogenic mediators in the development and progression of the disease. Finally, we introduce the concept of endometrial dissemination as result of a neuroendocrine-immune disequilibrium in response to high levels of perceived stress caused by cardinal clinical symptoms of endometriosis.

Whole genome deoxyribonucleic acid microarray analysis of gene expression in ectopic versus eutopic endometrium

OBJECTIVE

To use DNA microarrays to identify differentially expressed genes in eutopic endometrium compared with ectopic endometrium.

DESIGN

Prospective, cross-sectional, observational study.

SETTING

University Medical Center and Research Laboratory.

PATIENT(S)

Eleven women with endometriosis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Differential gene expression.

RESULT(S)

Seven hundred seventeen of the 53,000 probes on the whole human DNA microarrays were changed by twofold or greater in ectopic versus eutopic endometrium. Families of genes that were expressed differentially include genes that code for proteins associated with the immune system and inflammatory pathways, cell adhesion, cell-cell junctions, the extracellular matrix and its remodeling, cytoskeletal proteins, and signal transduction pathway components, among others.

CONCLUSION(S)

The altered immune environment may allow survival of endometriotic cells that enter the abdominal cavity. Alterations of cell adhesion-associated genes may contribute to the adhesive and invasive properties of ectopic endometrium, and changes in signal transduction pathways support a change in the communication among cells of the endometrial explant compared with eutopic endometrium. These families of differentially expressed genes provide multiple opportunities for the development and testing of new hypotheses regarding endometriosis.

Differential flow cytometric detection of intracellular cytokines in peripheral and peritoneal mononuclear cells of women with endometriosis

OBJECTIVE

The pathogenesis of endometriosis is related to functional changes in CD3+ and CD14+ cells observed both at the local and systemic level. Here we investigated whether, and if so, how the body compartment influences cytokine expression in stimulated peritoneal and peripheral CD3+ and CD14+ cells of women with endometriosis.

STUDY DESIGN

Isolated peripheral blood (PB) and peritoneal fluid (PF) mononuclear cells from women with endometriosis were cultured under non-adherent conditions and stimulated with PMA and ionomycin for 6h to induce intracellular cytokine synthesis of TNF-alpha, IFN-gamma, and IL-8 by CD3+ cells or with LPS for 9h to produce TNF-alpha, IL-6, IL-10, MCP-1, and IL-8 by CD14+ cells.

RESULTS

The percentages of positive CD3+ cells stained for TNF-alpha and IFN-gamma were significantly higher and those stained for IL-8 were significantly lower in PF compared with PB, this being independent of the stage of endometriosis. In contrast, the percentages of CD14+ cells producing TNF-alpha, IL-6, IL-10, MCP-1, and IL-8 were significantly higher in PB than PF of women with endometriosis.

CONCLUSIONS

Monocytes/macrophages and lymphocytes derived from the peripheral and peritoneal compartments of women with endometriosis differentially respond to stimulated cytokine synthesis induction. However, it is difficult to state whether the observed phenomenon is more related to body compartment influence per se or to the presence of endometriosis.

Endométriomes ovariens : effet de la kystectomie laparoscopique sur la réponse ovarienne en fécondation in vitro

OBJECTIVE

To investigate the follicular response to controlled ovarian hyperstimulation (COH) in IVF-ET cycles after laparoscopic ovarian cystectomy for large endometriomas.

PATIENTS AND METHODS

In the set of a retrospective controlled study, the medical records of 113 infertile women who underwent IVF-ET cycles after laparoscopic surgery were reviewed. The study group (A) consisted of 63 patients with severe pelvic endometriosis and endometrioma excision. The control group (B) consisted of 50 infertile patients with mild or minimal endometriosis. Interventions were laparoscopic ovarian cystectomy in the study group, and COH in both groups.

RESULTS

Groups A and B were not different in terms of epidemiologic data. The total numbers of recruited follicles (9.1+/-3.3 vs 10.6+/-4.2; P = 0.001), mature follicles (> or =16 mm) (4.2+/-1.7 vs 4.8+/-2.2; P = 0.04), mature oocytes retrieved (5.8+/-3.8 vs 7.4+/-4.6; P = 0.02), and fertilization rate (48.9+/-34.9 vs 61.8+/-32.1%; P = 0.02) observed in group A were lower than those observed in group B, respectively. While the mean number of rFSH ampoules (75 IU) was increased in group A (38.1+/-20.4) compared to group B (29.3+/-16.4; P = 0.004), cumulative pregnancy rates were similar in both groups (27.5+/-8.8% vs 37.2+/-10.6%; P = 0.37).

DISCUSSION AND CONCLUSIONS

Ovarian response was reduced during IVF-ET cycles in patients with history of severe endometriosis and laparoscopic excision of endometriomas compared to women with mild or minimal endometriosis without ovarian surgery.

Primary culture and morphologic observation of eutopic and ectopic endometrial cells from patients with endomehiosis

OBJECTIVE

To explore the method of primary culture for endometriotic cells and to find out the differences in morphological manifestations among endometriotic cells and eutopic endometrial cells sampled from patients with endometriosis and endometriosis-free women.

METHODS

Endometriotic and eutopic endometrial cells were cultured by modified method of primary culture. The endometriotic cell types were observed and differentiated under optical and electron microscopes.

RESULTS

The success rates for culture of eutopic endometrial cells from endometriosis-free women and patients with endometriosis were 91.67% and 93.75% respectively. The success rate for culture of endometriotic cells was 75.00%. The size of endometriotic glandular cells was similar to those of eutopic endometrial glandular cells from endometriosis-free women and patients with endometriosis. The chromatin was manifold and the nucleus was augmented in the endometriotic glandular cells. The endometriotic stromal cells were smaller than the eutopic endometrial stromal cells from endometriosis-free women and patients with endometriosis. Many tiny villi and protuberances on plasma membrane could be seen in the endometriotic stromal cells.

CONCLUSION

The success rate for culture of endometriotic cells can be elevated through improving the method of primary culture. The ultrastructures of endometriotic glandular and stromal cells are obviously different from those of eutopic endometrial glandular and stromal cells from endometriosis-free women and patients with endometriosis.

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.

Haptoglobin beta chain isoforms in the plasma and peritoneal fluid of women with endometriosis

OBJECTIVE

To estimate the expression of haptoglobin (Hp) beta chain isoforms in the peritoneal fluid (PF) and plasma (PL) of women with and without endometriosis.

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENT(S)

Seventy-two patients with endometriosis and 35 controls.

INTERVENTION(S)

Peritoneal fluid and PL samples were subjected to two-dimensional gel electrophoresis, silver stained, digitally captured, and compared by semiquantitative computerized analysis.

MAIN OUTCOME MEASURE(S)

Expression of Hp beta chain isoforms.

RESULT(S)

No significant difference was observed in the frequency of expression of the Hp beta chain isoforms between the two groups. One beta chain isoform (HpbetaE; molecular weight, 38.40 +/- 0.94 kD; and isoelectric point, 5.63 +/- 0.17) had significantly higher expression in both the PF and PL of women with endometriosis than in the PF and PL of controls. No significant difference was observed in HpbetaE expression between women with mild (revised American Fertility Society [rAFS], stage I-II) and severe (rAFS, stage III-IV) endometriosis. In the control group, HpbetaE expression was correlated with the phase of the menstrual cycle.

CONCLUSION(S)

Women with endometriosis have higher PF and PL levels of HpbetaE. Further investigation should be aimed at producing antibodies against the HpbetaE-specific epitopes to determine whether its measurement may improve the clinical diagnosis of endometriosis.

Haptoglobin expression by shed endometrial tissue fragments found in peritoneal fluid

OBJECTIVE

To confirm the endometrial glandular epithelial and stromal cells in tissue fragments recovered from peritoneal fluid and to quantify haptoglobin expression.

DESIGN

Prospective, randomized study.

SETTING

University of Missouri-Columbia School of Medicine and Health Care System.

SUBJECT(S)

Women undergoing laparoscopic surgery for diagnosis or treatment of endometriosis or for laparoscopic tubal cautery for desired sterilization.

INTERVENTION(S)

Aspiration of peritoneal fluid at laparoscopic surgery.

MAIN OUTCOME MEASURE(S)

Histological confirmation of endometrial glandular epithelial and stromal cells and evaluation of haptoglobin gene expression and protein localization in shed endometrial tissue fragments recovered from peritoneal fluid.

RESULT(S)

More visible tissue fragments were found in the peritoneal fluid from women with endometriosis (n = 28/65) than from that of women without endometriosis (n = 5/34). Of these tissues, endometrial glands and stroma were histologically confirmed in about half of women with endometriosis (n = 13/28) and without endometriosis (n = 3/5). Retrogradely shed endometrial tissues recovered from peritoneal fluid robustly express haptoglobin.

CONCLUSION(S)

Haptoglobin expression by retrogradely shed endometrial tissues in peritoneal fluid supports a mechanism whereby these purported precursors of endometriotic lesions escape immune destruction. Low recovery of histologically confirmed endometrial tissue fragments from peritoneal fluid reveals the potential difficulties for using these tissues for studies modeling the pathogenesis of endometriosis.

HLA-G is expressed by the glandular epithelium of peritoneal endometriosis but not in eutopic endometrium

BACKGROUND

HLA-G is a major histocompatability antigen with documented immune-regulatory function. Various epithelial cancers and tissue allografts have been noted to express HLA-G, which is postulated to aid in their escape from immunosurveillance. We evaluated peritoneal endometriosis and eutopic endometrium for the expression of HLA-G protein and gene transcript.

METHODS

Two experiments were performed: (i) archived tissue blocks from peritoneal endometriotic lesions (n = 15) and eutopic endometrium (n = 12) were evaluated for extent of protein immunostaining, and (ii) eutopic endometrial biopsies from women without (n = 17) and with (n = 24) endometriosis, and peritoneal endometriotic lesions (n = 14) were evaluated for presence of RNA transcript by in situ hybridization.

RESULTS

HLA-G protein localized in the glandular epithelium of 14 of 15 (93.3%) peritoneal endometriotic lesions, but not in stromal cells. HLA-G protein staining was absent in endometrial biopsies (n = 12). HLA-G gene transcript localized to the glandular epithelium in 13 of 14 (92.8%) peritoneal endometriotic lesions. HLA-G transcript was never observed in eutopic endometrium, regardless of cycle stage or whether from women with (n = 24) or without (n = 18) endometriosis.

CONCLUSIONS

HLA-G is expressed by endometriotic glandular epithelium but not by eutopic endometrium under normal conditions. Differential expression of HLA-G suggests that peritoneal inflammation or cellular stress may up-regulate mechanisms to promote ectopic endometrial survival.

Future Directions in Endometriosis Research

Endometriosis is an important gynecological disease, pathologically defined by the ectopic presence of both endometrial glands and stroma, and clinically associated with pelvic pain and infertility. Our current knowledge of the pathogenesis, pathophysiology of related infertility, and spontaneous evolution is still limited, although endometriosis has been described for many years. Future research in endometriosis needs to focus on pathogenesis studies in the baboon model and on the early interactions between endometrial and peritoneal cells in the pelvic cavity at the time of menstruation. Proteomic and genomic approaches are needed to detect potential differences between eutopic endometrium and myometrium in women with and without endometriosis. Immunomodulatory drugs inhibiting endometriosis-associated pelvic inflammation may offer new medical treatment for endometriosis in the future.

Endometriosis

Endometriosis is an oestrogen-dependent disorder that can result in substantial morbidity, including pelvic pain, multiple operations, and infertility. New findings on the genetics, the possible roles of the environment and the immune system, and intrinsic abnormalities in the endometrium of affected women and secreted products of endometriotic lesions have given insight into the pathogenesis of this disorder and serve as the background for new treatments for disease-associated pain and infertility. Affected women are at higher risk than the general female population of developing ovarian cancer, and they also may be at increased risk of breast and other cancers as well as autoimmune and atopic disorders. Clinicians should assess and follow up affected women for these and other associated disorders. There will probably be a new repertoire of approaches for treatment and perhaps cure of this enigmatic disorder in the near future.

Macrophages are activated by 17beta-estradiol: possible permission role in endometriosis

On the basis of the common occurrence of high concentration of estrogen and activated macrophages in patients with endometriosis, we postulate that interaction between 17beta-estradiol and macrophage may be an important affair in endometriosis. So our study was focused on the effect of 17beta-estradiol on macrophage. First morphology of macrophages was examined with environmental scanning electron microscopy. Increased size, extension of more microvilli, expression of retraction fibers and elaboration of membrane ruffles were detected in 17beta-estradiol treated macrophages. Then Nitrate and nitrite level in the supernatant was measured by the method of Griess and iNOS expression was analyzed using immunohistochemical staining. It showed that 17beta-estradiol could induce NO release from peritoneal macrophages and expression of iNOS was increased. Also more TNF-alpha in supernatant that was measured by MTT via L929 cell was produced by macrophages under the inducing of 17beta-estradiol. Furthermore, [Ca2+]i, which was viewed by microscope in a laser scanning confocal unit, elevated 39.8% in peritoneal macrophages after 17beta-estradiol 100 nmol/L treated. The results above demonstrated that peritoneal macrophage had been activated in both morphology and cytokine line when interaction with 17beta-estradiol, which indicated that macrophage activated by 17beta-estradiol might play a permission role in development of endometriosis.

Understanding endometriosis is the key to successful therapeutic management

Understanding endometriosis on a molecular, biochemical, and genetic level will lead to better methods for the diagnosis and therapeutic management of this enigmatic disease.

Glycosylation and over-expression of endometriosis-associated peritoneal haptoglobin

Peritoneal endometriotic tissues synthesize and secrete haptoglobin (pHp), which has an analogous nucleotide sequence to hepatic haptoglobin found in serum (sHp). This study performed enzymatic digestions and lectin binding assays to determine if differences in protein glycosylation exist between sHp and pHp, which may provide insight into pHp function and/or identify epitopes for development of novel methods of medical management of endometriosis. To reduce the dependence on surgical collection of peritoneal tissues from women, recombinant peritoneal Hp (rpHp) was produced and its glycosylation analyzed for future functional studies. These results showed the apparent molecular weight of pHp was 3 kDa smaller than sHp. Desialylation and complete N-deglycosylation elicited similar shifts in sHp and pHp electrophoretic migration, suggesting similar sialic acid content and indicating the 3 kDa variance was due to carbohydrate content, not protein degradation, respectively. Sequential deglycosylation of the four sHp N-glycan chains caused a 3 kDa shift per N-glycan removed suggesting the 3 kDa difference between sHp and pHp may be one N-glycan chain. Lectin ELISA and lectin-blotting analyses demonstrated increased pHp and rpHp interactions with MAL and LTL but no difference in binding to SNL compared to sHp from healthy individuals, identifying variations in the ratios of alpha(2-3) to alpha(2-6) sialic acid and fucose residues. Recombinant pHp was 100-fold over-expressed with a similar glycosylation pattern to pHp, albeit in an unprocessed alpha-beta Hp polypeptide form. These results are the first to identify differences between pHp and sHp glycosylation and lay groundwork further studies to characterize anomalies in glycan composition and structure, which likely impart pHp with known immunomodulatory functions and may be used as epitopes for development of immune based therapeutics for novel, non-surgical management of endometriosis.