The 1972 Stockholm Conference put environmental protection on the global agenda for the first time. But since then, biodiversity losses and increasing threats have outpaced the conservation response. A step change is needed to reverse this trend and will require scaled-up action across society, including from governments, businesses, and financial institutions.

Objective: To study the localization of and quantify different immune cell populations in red, black, and white peritoneal endometriotic lesions and compare immune cell densities between lesions and the surrounding tissue. Design: Cross-sectional study. Setting: Teaching hospital, university research laboratory. Patient(s): Participants undergoing laparoscopic excision of endometriosis were recruited from gynecological operating theaters at Royal Prince Alfred Hospital, Sydney (n = 28). Intervention(s): Immunohistochemical staining for and quantification of dendritic cells (mature and immature), T cells (effector, cytotoxic, and regulatory), B cells, and macrophages in endometriotic peritoneal lesions and the surrounding tissue. Main Outcome Measure(s): Immune cell densities and aggregates were quantified. Result(s): Red and black lesions are significantly more likely to be surrounded by immune cell aggregates than white lesions (P=.036). In the tissue surrounding the peritoneal endometriotic lesions, there was a consistent pattern of greater and more variable density of immune cell populations for red lesions than black or white lesions and a range of significant positive correlations between densities of different immune populations (all P <=.004; not observed within the lesion stroma). Conclusion(s): There is a greater presence of immune cells in the tissue surrounding earlier/red and black lesions than older scarred white lesions, particularly in the form of immune cell aggregates, indicating an immunologic response in close proximity to the adjacent lesion. The relationship between densities of immune populations in the tissue surrounding the lesions suggests complementary recruitment and local interactions between cells. Categorizing immune cell populations in proximity to peritoneal endometriotic lesions may improve the understanding of lesion persistence and transition to older white appearances. Early (red) peritoneal endometriotic lesions are surrounded by a greater density of immune cells, including immune aggregates, than later (black or white) lesions. These immune cells may support lesion persistence. (c) 2020 by American Society for Reproductive Medicine.)

In endometriosis, the lymphatic and immune systems are implicated in disease establishment and progression. The objective of this pilot study was to examine endometrial-like, and for the first time, immune cell populations in lymph nodes associated with deep infiltrating endometriosis (DIE) bowel lesions. Premenopausal women undergoing excision of endometriosis and/or hysterectomy were included. DIE bowel lesion-associated (n = 10) and other pelvic (n = 15) lymph nodes were studied. Samples were immunohistochemically stained for endometrial-like cells (CD10), T cells (CD3, CD4, CD8, and FoxP3), dendritic cells (DC; DC-Lamp and DC-Sign), B cells (CD20, CD79 and plasma), macrophages (CD68), and natural killer cells (NK; CD57). Cell abundance (percentage positive area) and antigen expression (optical density; OD) were quantified. Endometrial-like cells and each immune cell population were present in all studied nodes. The DIE bowel lesion-associated nodes showed features of immune activation, with T cell proliferation (CD3+ area p = 0.007, CD4+ area p = 0.015 compared with other pelvic nodes); and a mixture of helper and regulatory T cells, B cells, DCs, macrophages, and plasma cells present in the paracortex. In DIE bowel lesion-associated compared with other pelvic nodes, CD10+ endometrial-like cells were reduced (percentage positive area p < 0.001, OD p = 0.004). This study provides new insight into lymphatic and immune system involvement in advanced endometriosis. In particular, we have shown evidence of immune activation in DIE lesion-associated nodes. This was despite lower endometrial-like cell numbers compared with other pelvic nodes. The observations contribute to a developing understanding of the local immune response to advanced disease.

Detection of unique nerve fibres in the endometrium of women with endometriosis and subsequently in their peritoneal lesions has led to increased interest in studying their relationship with infertility and pain. Blood vessels and nerves fibres course throughout the body in an orderly pattern, often alongside one another. Although superficially distinct, the mechanisms involved in wiring neural and vascular networks seem to share similarities. We found that nerve fibres and blood vessels traverse the endometriotic peritoneal tissue in slightly different ways with variations in length densities (Lv), branch point density (Bv), segment length between branch points (Lv/Bv) and capillary radial diffusion distance r(diff). The capillary radial diffusion distance r(diff) and the spatial co-localisation distance in conjunction with nerve fibres fell within range for the facilitation of the physiological diffusion and transfer of molecular substances and the transmission of electrical signals to co-ordinate tasks within the endometriotic peritoneal lesion.Biological systems exist and operate in a three-dimensional environment and blood vessels and nerve trunks often travel in close apposition through many tissues; therefore, it was a priority to assess (CD31+) blood vessel and (PGP9.5+) nerve fibre three-dimensional structural features from qualitative and quantitative perspectives in peritoneal endometriotic lesions. Utilising laser scanning confocal microscopy allowed for considerable precision in the study of endometriotic peritoneal lesion blood vessel and nerve fibre co-localisation and three-dimensional relationships.

Introduction: Endometriosis is an inflammatory disease characterised by the presence of endometrial-like tissue outside the uterus and affects approximately 10%–15% of women in their reproductive years. Pain is one of the predominant symptoms of the disease. Oxidative stress is involved in the pathophysiology of endometriosis and develops when there is an imbalance between the reactive oxygen species and reactive nitrogen species production, and the elimination capacity of antioxidants in the reproductive tract. High levels of reactive oxygen species can induce pain indirectly through oxidative stress-associated inflammation or directly through sensitising the nociceptive neurons that transmit the signals to the cerebral sensory cortex which are perceived as a feeling of pain. Mitochondria are the main source of reactive oxygen species, which generate through oxidative phosphorylation. Given that the mitochondria are involved in reactive oxygen species formation and energy production, which are required for the activation and proliferation of peripheral lymphocytes, it has been suggested that mitochondrial DNA variants are involved in the pathogenesis of endometriosis. This study has provided a better understanding of maternally inherited risk factors which contribute to the pain mechanisms associated with endometriosis. Results: Mitochondrial DNA haplogroup H was found to be significantly higher in women with endometriosis. This study was the first to report the association between the European mitochondrial haplogroup H and the risk of pain associated with endometriosis. Discussion: The results suggest that there are maternally inherited risk factors in women with endometriosis causing high reactive oxygen species production and oxidative stress, which facilitate pain generation in women with endometriosis.

Introduction: The purpose of this study was to investigate the detailed nature of menstrual characteristics, bleeding and other symptoms in women with and without endometriosis. Pelvic pain symptoms in this cohort have been reported elsewhere. Method: This is a self-administered cross-sectional study and was conducted using a structural questionnaire. A total of 737 women completed the study: women with endometriosis (n = 529) and with no current gynaecological complaint, 'control' (n = 208). Results: Some of the key findings in this study included significant differences between the control and endometriosis subjects in terms of bleeding symptoms, increased length and heaviness of menses, rectal and bladder bleeding, infertility and obstetric complications which were all more common in the endometriosis group. Other symptoms found to have a highly significant positive association with endometriosis included abdominal bloating, low resistance to infection, fatigue, increased urinary frequency, diarrhoea and constipation (p < 0.000). Data were cross-tabulated to examine the association of a number of symptoms to each other. The relationship of symptoms to a range of psychosocial factors was investigated to determine how the effects of endometriosis impacted on the life of subjects. Most women reported that endometriosis sometimes or often interfered with daily aspects of their life. Conclusion: The range of non-pain symptoms in women with endometriosis was generally much more diverse and extensive than recognised by most clinicians.

Objective:To investigate the detailed nature of pain symptoms reported by women with endometriosis and those without current gynecological complaint.Design:Self-administered cross-sectional study was conducted using a structured questionnaire.Setting:Teaching hospital clinic, specialist gynecologist, and family practice patients; endometriosis community support group members; and university staff and students.Subjects:A total of 737 women returned completed surveys: women with endometriosis ( n = 529) and with no current gynecological complaint ( n = 208).Intervention(s):None.Main outcome measure(s):Demographics, experience of pain symptoms: frequency, severity, and characteristics.Results:All pain symptoms were significantly more common among women with endometriosis compared with controls. Women with endometriosis all reported experiencing dysmenorrhea to some degree ( N = 527, two missing), although the severity was “slight” for 5%. Dyspareunia was reported by 92% of women with endometriosis, most commonly during intercourse, rather than at the start or post-coital. The other pain symptoms experienced by women with endometriosis, in order of frequency, were lower back pain (93%), pain at ovulation (87%), pelvic pain other than during menses, ovulation, urination or intercourse (79%), dysuria (71%), and rectal pain (67%). The great majority of women with endometriosis reported multiple sources and types of pain. Among women with endometriosis there were clear associations between the severity of dysmenorrhea and the frequency of experiencing dyspareunia and other pain symptoms.Conclusion:Pain symptoms in women with endometriosis were generally much more extensive and complex than recognized by most clinicians.

Endometrial polyps are overgrowths of endometrial glands that typically protrude into the uterine cavity. Endometrial polyps are benign in nature and affect both reproductive age and postmenopausal women. Although endometrial polyps are relatively common and may be accompanied by abnormally heavy bleeding at menstruation. In asymptomatic women, endometrial polyps may regress spontaneously, in symptomatic women endometrial polyps can be treated safely and efficiently with hysteroscopic excision.

Endometriosis is a complex gynaecological condition affecting women of reproductive age. It is characterised by the presence of lesions containing endometrial glands and stroma outside the uterus. The disease is typically associated with pelvic pain (including dysmenorrhoea and dyspareunia), infertility and bowel-related symptoms. Endometriotic lesions have a highly variable presentation and most commonly occur in the abdominal cavity. These lesions are broadly classified into peritoneal, ovarian and deep infiltrating endometriosis. There have been observations of increased density of nerve fibres and neurological molecules in the endometriotic lesions compared to the uninvolved peritoneum of women without endometriosis and the presence of unmyelinated nerve fibres were higher near the glands. The lesion sites are characterised by a range of immunological alterations, and specific immune cell populations have also been known to synthesise and secrete neurogenic factors. Endometriotic lesions are capable of producing prostaglandins which are direct generators of pain and are capable of inducing inflammation. Diagnosing the disease involves direct visualisation of the lesions through a laparoscopic or laparotomy, which is followed by histopathological examination of biopsied or excised lesions. The staging of endometriosis due to its complexity is highly variable as presentation and gaps in knowledge pose a great challenge in the classification of the disease. The medical management of endometriosis aims at providing adequate analgesia and suppression of the activity of the lesion. A better understanding of endometriotic lesion relationships between innervations and specific clinical characteristics may elucidate aspects of pain mechanisms and infertility in endometriosis and facilitate the development of novel therapeutic approaches.

Endometriosis is a gynaecological disorder characterised by the presence of endometrial-like tissue outside the uterus. It affects 10-15% of women during their reproductive age. Endometriosis is a highly variable condition in terms of presenting symptoms, anatomical extent of disease, rate of progression, incidence of infertility, response to treatment and the likelihood of recurrence. The aetiology and the pathogenesis of the disease are poorly understood. Endometriosis has a wide range of symptoms or can be asymptomatic, this makes the diagnosis of the disease difficult. The definitive diagnosis is surgical, usually via laparoscopy with histological confirmation. There is often a long delay in diagnosis, 8-12 years, from the onset of symptoms till a definitive diagnosis is made. Endometriosis is a progressive disease and long delays before effective treatment allows the disease to advance.

Baboon ( Papio anubis) models of endometriosis are thought to mimic the early stages of spontaneous human peritoneal endometriotic disease. The objective of this study was to investigate the presence and course of nerve fibre ingrowth during peritoneal lesion formation in specimens collected at 3 months (early stage of lesion development) and 15 months (late stage of lesion development) after disease initiation compared to pelvic peritoneum (control). Five-micron sections of paraffin-embedded peritoneal lesions were obtained from normally cycling baboons with 3-month (n = 12), 15-month (n = 12) induced endometriosis and pelvic peritoneum (n = 10) from baboons with no endometriosis. Immunohistochemical staining was performed with specific antibodies: protein gene product 9.5 – broad marker of nerve fibres and neurones, neuropeptide Y – sympathetic neurones, substance P – sensory neurones, vasoactive intestinal peptide – parasympathetic neurones, nerve growth factor – development of new neurones and high-affinity receptor for nerve growth factor (tropomyosin receptor kinase A) – neuronal differential. Significantly, more nerve fibres were identified in peritoneal endometriotic lesions collected 15 months after the initiation of experimental protocols compared with 3-month and control samples (p < 0.001). Nerve fibres were immunoreactive for all the tested markers – protein gene product 9.5, neuropeptide Y, substance P, vasoactive intestinal peptide, nerve growth factor and tropomyosin receptor kinase A – indicating the presence of different types of nerve fibres. In conclusion, peritoneal lesions of endometriosis in a nonhuman primate model of endometriosis were found to be progressively and spontaneously innervated by both myelinated and unmyelinated sensory nerve fibres, parasympathetic and sympathetic neurones. These nerve fibres may play an important role in the mechanisms of pain generation in this condition.

Objective: Endometrial polyps are localised growths of endometrial tissue containing glands, stroma and blood vessels, covered with epithelium. The reported prevalence of endometrial polyps is dependent upon the population being studied and the uterine imaging technique utilised. The light microscopy literature provides very little information regarding their microvasculature and lymphatic systems; however, a plethora of ultrasound data demonstrating single central arteries in most medium- or large-sized endometrial polyps are well documented. Methods: Archived formalin-fixed paraffin-embedded blocks of endometrial curettings were retrieved from files for women with confirmed endometrial polyps ( n = 20) and women with normal endometrium (control endometrium; n = 32). Immunohistochemistry was performed with the antibodies CD31 (blood vessels) and D2-40 (lymphatics). Blood vessels and lymphatics were quantified in endometrial polyps and adjacent, distant and control endometrium. Results: CD31 and D2-40 staining was present in all specimens, although there were no significant differences in blood vessel ( F(3,70) = 2.36, p = 0.079) and lymphatic ( F(3,70) = 0.16, p = 0.920) densities between endometrial polyps as well as adjacent, distant and control endometrium. There were also no significant differences in women with endometrial polyp-associated bleeding and those with no bleeding. In relation to infertility, there were no significant differences found in blood and lymphatic densities between women with endometrial polyps who were infertile and those with endometrial polyps who were fertile. Conclusion: Small blood vessel wall and perivascular structures rather than the distribution of vessels may be associated with abnormal bleeding.

Endometriosis is a gynaecological disease that occurs in approximately 10% to 15% of women of reproductive age and up to 47% of infertile women. The presence of implants of endometrial-like glands and stroma outside the uterus, characteristic of this disease, induce a wide variety of symptoms, mainly pelvic pain and infertility. Women suffering from this condition experience great distress, which significantly affects their quality of life. Numerous studies attempting to decipher the pathogenic mechanisms of endometriosis have been conducted around the world, yet its aetiology still remains unknown. It is widely believed that in women with endometriosis, the endometrium has characteristic features that allow the formation of implants once fragments have entered the peritoneal cavity through retrograde menstruation. Furthermore, a strong genetic tendency to develop the disease has been reported among patients and first-degree relatives. Thanks to the recent technological advances achieved in genomics and bioinformatics, a number of studies have had the potential to analyse several aspects of the pathogenesis of endometriosis from a genetic perspective. Due to the recent identification of nerve fibres in the endometrium of women with endometriosis, research on the neurogenesis of the disease has increased in the past few years. However, the genetic aspects of nerve growth in endometriosis have not been analysed in depth and further research providing important insights into the mechanisms that mediate pain in affected patients has the potential to contribute substantially to the future management of the condition.

Endometriosis is a gynaecological disorder characterised by the presence of endometrial-like tissue outside the uterus. It affects 10–15% of women during their reproductive age. The existence of close and complex relationship between chronic pelvic pain and endometriosis are widely recognised. However, the mechanisms of pain generation in women with endometriosis remain poorly understood. Immunohistochemistry was used to assess the density of nerve fibres stained with protein gene product 9.5 (PGP9.5) and the expression of various neurotrophins including glial cell derived neurotrophic factor (GDNF), persephin, neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) and neuronal guidance molecules semaphorin 3E and Slit-2 and their receptors Plexin-D1 and Robo4 in peritoneal ectopic lesions from women with endometriosis and uninvolved peritoneum samples. Neurotrophins and neuronal guidance molecules and their receptors are synthesised in situ within peritoneal ectopic lesion which suggest their role in facilitating and maintaining the growth of nerve fibres. These molecules were found to be overall most highly expressed in the glands of endometriotic peritoneal lesions. In addition, the presence of ectopic lesions within the peritoneal cavity may affect the environment; in turn, the peritoneum altered appeared to play a role in the growth of nerve fibres and their development and maintenance in peritoneal lesions. Through exploring different neuronally active factors in and around ectopic lesions which may be contributing to pain generation, this study provides an insight and better understanding of the pain mechanisms associated with peritoneal endometriosis.

The initiation of endometriosis in women is difficult to investigate, because there is usually a delay of several years from the onset of lesion development to the clinical diagnosis. Animal models of endometriosis, on the other hand, provide an important contribution to the investigation of the disease pathogenesis and the efficacy of therapeutic intervention strategies.

Background Dysfunctional immune response may be implicated in endometriosis pathogenesis, and dendritic cells (DC) may play greater roles in this response than previously recognized. This study set out to evaluate peripheral blood and endometrial DC population changes in the presence and absence of endometriosis pathology. Methods Endometrial (n = 83) and peripheral blood samples (n = 30) were subjected to immunohistochemical techniques and flow cytometry, respectively, to assess DC populations in women with and without endometriosis. Three circulating DC subsets (MDC1, MDC2 and PDC, expressing CD1c, CD303 and CD141), and late-stage mature endometrial DCs (using DC-LAMP antibody) were investigated. Results A highly significant reduction in CD1c intensity on MDC1 populations in peripheral blood was observed between normal cycle proliferative and menstrual phases (p = 0.025), but not in women with endometriosis, in whom CD1c intensity was markedly increased at the time of menstruation (p = 0.05). A significant reduction in peripheral blood MDC2 (p = 0.016) and apparent reduction in endometrial DC-LAMP+ DC (trend, p = 0.062) were observed in women with endometriosis compared with controls, consistent with our preliminary DC data. Conclusions Cyclical variation in endometrial and circulating DC populations appears to be crucial during normal menstrual cycles and in the establishment of pregnancy. In endometriosis, circulating and endometrial DC populations are significantly dysregulated at a number of levels, and are likely to contribute to inefficient immunological targeting of endometrial fragments shed at menstruation, facilitating their survival and establishment of endometriosis.