Pain in Endometriosis

Whole exome sequencing reveals novel candidate variants for endometriosis utilizing multiple affected members in a single family

BACKGROUND

Endometriosis is an estrogen-dependent, chronic inflammatory disease that affects 10% of women during the reproductive ages. Despite the estimated 50% heritability for the condition, only 26% was associated with common genetic variants. Thus, necessity of identifying rare variants for the missing heritability is implicated in the literature. Therefore, our study aimed to identify novel rare genetic variants involved in the pathogenesis of endometriosis utilizing a family of multiple affected members.

METHODS

A family composed of four affected women along with their two unaffected mothers were recruited at a single gynecology and infertility clinic specialized in endometriosis. All patients presented with endometriomas, which was visualized by transvaginal ultrasonography. Two affected individuals had received laparoscopic endometrioma excision and therefore were diagnosed with recurrent disease. One mother had a history of endometrial serous adenocarcinoma (ESC) for which she underwent hysterectomy with bilateral oophorectomy. Three endometriosis cases were whole exome sequenced on Illumina NextSeq 550 platform with an average of 90% coverage. Candidate genes were confirmed by Sanger sequencing and followed-up with family segregation.

RESULTS

Novel rare variants were identified in TNFRSF1B (NM_001066.3: c.1072G>A, p.(Ala358Thr)) and GEN1 (NM_001130009.3: c.1574C>T, p.(Ser525Leu)) as possible genetic causes of endometriosis. A third novel rare variant was identified in CRABP1 (NM_004378.3:c.54G>C, p.(Glu18Asp)) only on the mother with ESC history and her daughters.

CONCLUSION

Novel candidate genetic variants that might contribute to endometriosis were suggested that need replication through independent cohorts or validation by functional studies. The family has also received genetic counseling and that the affected daughters are on clinical follow-up, accordingly.

Correlation between Anatomopathological Aspects and Pelvic Pain in Women with Deep Infiltrating Endometriosis

OBJECTIVE

 To correlate the morphological aspects with pelvic pain in women with deep infiltrating endometriosis.

METHODS

 A retrospective study with 67 women with deep endometriosis who underwent surgical treatment in a tertiary hospital from 2007 to 2017. The following variables were considered: age, parity, body mass index, site of involvement, hormonal treatment before surgery, pelvic pain, and morphometric analysis. The histological slides of the surgical specimens were revised and, using the ImageJ software for morphometric study, the percentages of stromal/glandular tissues were calculated in the histological sections.

RESULTS

 The mean age of the women was 38.9 ± 6.5 years. The mean pain score was 8.8 ± 1.9 and the mean time of symptomatology was 4.7 ± 3.5 years, with 87% of the patients undergoing hormone treatment prior to surgery. The average expression of CD10, CK7, and S100 markers was 19.5 ± 11.8%, 9.4 ± 5.9%, and 7.9 ± 5.8% respectively. It was found that the greater the expression of CD10, the greater the level of pain (p = 0.02). No correlation was observed between the expression of CD10, CK7, and S100 markers and age and duration of symptoms.

CONCLUSION

 Women with deep infiltrating endometriosis have a positive association between the level of pain and the fibrosis component in the endometrial tissue's histological composition.

Endometriosis: Classification, pathophysiology, and treatment options

The human endometrium is a complex hormone-target tissue consisting of two layers: the lower basalis, and the upper functionalis. The latter of the two goes through a cycle of thickening and shedding without residual scarring or loss of function. This cycle, known as the menstrual cycle, occurs on a monthly basis in most of healthy reproductive-age women. It is, however, associated with a number of reproductive diseases, endometriosis being one of them. Endometriosis is defined as the presence of endometrium at ectopic sites within the peritoneum or, more rarely, other locations outside the abdominal area. It affects around 6-10% of reproductive-age women in the world and causes debilitating pain, heavy menstrual bleeding, pain during penetrative sex, and infertility. The etiology of the disease is not yet fully understood but the generally accepted theory is that the endometriotic lesions originate from viable eutopic endometrial cells that flow back into the peritoneum through the process of retrograde menstruation. Endometriosis is usually classified into four stages: minimal, mild, moderate, and severe, though it is important to note that the presentation of symptoms does not necessarily correspond to the disease progression. The immune system plays an important role in supporting the viability and growth of ectopic endometriotic tissue, all the while promoting chronic inflammation at the lesion sites, which causes prolonged pain. There is no definitive cure for endometriosis, but there are several options for symptom management, including laparoscopy, hormonal therapy, the use of NSAIDs, dietary changes, exercise, and, in cases when all conservative treatments fail, hysterectomy.

Endometriosis-Related Chronic Pelvic Pain

Endometriosis, which is the presence of endometrial stroma and glands outside the uterus, is one of the most frequently diagnosed gynecologic diseases in reproductive women. Patients with endometriosis suffer from various pain symptoms such as dysmenorrhea, dyspareunia, and chronic pelvic pain. The pathophysiology for chronic pain in patients with endometriosis has not been fully understood. Altered inflammatory responses have been shown to contribute to pain symptoms. Increased secretion of cytokines, angiogenic factors, and nerve growth factors has been suggested to increase pain. Also, altered distribution of nerve fibers may also contribute to chronic pain. Aside from local contributing factors, sensitization of the nervous system is also important in understanding persistent pain in endometriosis. Peripheral sensitization as well as central sensitization have been identified in patients with endometriosis. These sensitizations of the nervous system can also explain increased incidence of comorbidities related to pain such as irritable bowel disease, bladder pain syndrome, and vulvodynia in patients with endometriosis. In conclusion, there are various possible mechanisms behind pain in patients with endometriosis, and understanding these mechanisms can help clinicians understand the nature of the pain symptoms and decide on treatments for endometriosis-related pain symptoms.

Mechanisms of peripheral sensitization in endometriosis patients with peritoneal lesions and acyclical pain

PURPOSE

Endometriosis (EM) is one of the most frequent differential diagnoses concerning chronic pelvic pain. Women under hormonal therapy (HT) often benefit from it but sometimes suffer a setback and develop acyclical pelvic pain. Due to the assumption that mechanisms of neurogenic inflammation are involved in the generation of chronic pelvic pain, we aimed to investigate the expression of sensory nerve markers in EM-associated nerve fibers of patients with/without HT.

METHODS

Laparoscopically excised peritoneal samples from 45 EM and 10 control women were immunohistochemically stained for: PGP9.5, Substance P (SP), NK1R, NGFp75, TRPV-1, and TrkA. Demographics and severity of pain were documented.

RESULTS

EM patients showed a higher nerve fiber density (PGP9.5 and SP) and increased expression of NGFp75, TRPV1, TrkA, and NK1R in blood vessels and immune cells compared with controls. Patients with HT have cycle-dependent pelvic pain but suffer from acyclical pelvic pain. Interestingly, reducing NK1R expression in blood vessels under HT was observed. A correlation between dyspareunia severity and nerve fibers density and between NGFRp75 expression in blood vessels and cycle-dependent pelvic pain severity was observed.

CONCLUSION

Patients under HT have no ovulation and no (menstrual) bleeding, which correlate with inflammation and cyclical pain. However, acyclical pain seems to be due to peripheral sensitization once it is present under treatment. Neurotransmitters, like SP and their receptors, are involved in mechanisms of neurogenic inflammation, which are relevant for pain initiation. These findings indicate that in both groups (EM with/without HT), neurogenic inflammation is present and responsible for acyclical pain.

Does treating pain with alcohol affect drinking reduction among women with HIV enrolled in a clinical trial of naltrexone?

BACKGROUND

Many women living with HIV (WLWH) experience pain. Alcohol use with the intent to treat pain could lead to hazardous drinking and difficulty in reducing drinking. Naltrexone acts on opioid receptors important for pain regulation and is an approved treatment for alcohol use disorder. In this secondary analysis of a randomized double-blind placebo-controlled naltrexone clinical trial, the goals were to (1) compare alcohol reduction between women who drank to treat pain and those who did not and (2) examine differences in alcohol reduction by both drinking intention and treatment arm.

METHODS

Women living with HIV (N = 194, mean age 48.3 years, 83% non-Hispanic Black, 11% Hispanic) with hazardous drinking (>7 drinks/week) were randomized to receive daily treatment with naltrexone 50 mg or placebo for 4 months. Study visits occurred at baseline and 2, 4, and 7 months (posttreatment). The number of drinks/week was measured using the Timeline Follow Back. Use of alcohol to treat pain was self-reported. Participants were categorized as using alcohol to treat pain or not and in the naltrexone or placebo group. Chi-square, t-test, MANOVA, and sequential mixed effects models were used to determine group differences in demographic factors, mean/drinks per week, and percent change in mean drinks/week at baseline and each follow-up visit.

RESULTS

There was a consistent decrease in drinking throughout the study. There was not a significant difference in mean drinks/week at any point in the study between women who used alcohol to treat pain and those who did not. When considering treatment arm, at 2 months only those who did not use alcohol to treat pain in the naltrexone group had a significantly lower mean drinks/week than the other groups (p = 0.007); all groups had similar decreases in drinking from 4 months onward.

CONCLUSION

In the naltrexone group, WLWH who drank to treat pain reduced their alcohol consumption more slowly than WLWH who did not drink to treat pain. Replication of these findings would suggest that alcohol treatment guidelines should address pain as a factor in drinking outcomes.

Neuroproliferative dyspareunia in endometriosis and vestibulodynia

INTRODUCTION

Endometriosis is a common cause of deep dyspareunia, while provoked vestibulodynia is a common cause of superficial dyspareunia. The etiology of dyspareunia in both conditions is multifactorial and may include the role of local nerve growth (neurogenesis or neuroproliferation) that sensitizes pelvic structures and leads to pain with contact.

OBJECTIVES

To review the evidence for neuroproliferative dyspareunia in endometriosis and provoked vestibulodynia.

METHODS

Narrative review.

RESULTS

The pelvic peritoneum and vulvar vestibule receive somatic and autonomic innervation. Various markers have been utilized for nerve subtypes, including pan-neuronal markers and those specific for sensory and autonomic nerve fibers. The nerve growth factor family includes neurotrophic factors, such as nerve growth factor and brain-derived neurotrophic factor, and their receptors. Studies of endometriosis and provoked vestibulodynia have demonstrated the presence of nerve fibers around endometriosis epithelium/stroma in the pelvic peritoneum and within the vulvar vestibule. The number of nerve fibers is higher in these pain conditions as compared with control tissue. Nerve growth factor expression by endometriosis stroma and by immune cells in the vulvar vestibule may be involved in local neuroproliferation. Local inflammation is implicated in this neuroproliferation, with potential roles of interleukin 1β and mast cells in both conditions. Several studies have shown a correlation between nerve fibers around endometriosis and dyspareunia severity, but studies are lacking in provoked vestibulodynia. There are several possible clinical ramifications of neuroproliferative dyspareunia in endometriosis and provoked vestibulodynia, in terms of history, examination, biopsy, and surgical and medical treatment.

CONCLUSIONS

A neuroproliferative subtype of dyspareunia may be implicated in endometriosis and provoked vestibulodynia. Additional research is needed to validate this concept and to integrate it into clinical studies. Neuroproliferative pathways could serve as novel therapeutic targets for the treatment of dyspareunia in endometriosis and provoked vestibulodynia.

Robotic multiple sigmoid and rectal mucosa skinning in a multicentric deep infiltrating bowel endometriotic nodules: a case report

Endometriosis is a benign gynecological disease characterized by the presence of endometrial tissue outside the uterus. The eradication of non-gynecological localizations represents the real surgical challenge. A 29-year-old woman underwent robotic surgery with the Da Vinci system (Intuitive Surgical Inc.) for a diagnosis of stage IV deep endometriosis. The patient presented with 5 cm left ovarian endometrioma, an infiltration of the left posterior parametrium, and bilateral ureteral endometriosis. Once inside the pelvic cavity, deep intestinal infiltrating endometriosis implants were confirmed as triple, multicentric, and multifocal lesions, affected distal sigmoid, rectosigmoid junction, and upper rectum. An expert multiple excision, sparing the intestinal mucosa, was performed. To our knowledge, this is the first description of a multiple robotic shaving of multicentric endometriotic intestinal lesions. After the surgery, a normal diet was quickly restored, accelerating the recovery of the physiological peristalsis and the overall recovery time.

Sensory stimulations potentializing digital therapeutics pain control

For the past two decades, using Digital Therapeutics (DTx) to counter painful symptoms has emerged as a novel pain relief strategy. Several studies report that DTx significantly diminish pain while compensating for the limitations of pharmacological analgesics (e.g., addiction, side effects). Virtual reality (VR) is a major component of the most effective DTx for pain reduction. Notably, various stimuli (e.g., auditory, visual) appear to be frequently associated with VR in DTx. This review aims to compare the hypoalgesic power of specific stimuli with or without a VR environment. First, this review will briefly describe VR technology and known elements related to its hypoalgesic effect. Second, it will non-exhaustively list various stimuli known to have a hypoalgesic effect on pain independent of the immersive environment. Finally, this review will focus on studies that investigate a possible potentialized effect on pain reduction of these stimuli in a VR environment.

Insights from Mendelian randomization and genetic correlation analyses into the relationship between endometriosis and its comorbidities

BACKGROUND

Endometriosis remains a poorly understood disease, despite its high prevalence and debilitating symptoms. The overlap in symptoms and the increased risk of multiple other traits in women with endometriosis is becoming increasingly apparent through epidemiological data. Genetic studies offer a method of investigating these comorbid relationships through the assessment of causal relationships with Mendelian randomization (MR), as well as identification of shared genetic variants and genes involved across traits. This has the capacity to identify risk factors for endometriosis as well as provide insight into the aetiology of disease.

OBJECTIVE AND RATIONALE

We aim to review the current literature assessing the relationship between endometriosis and other traits using genomic data, primarily through the methods of MR and genetic correlation. We critically examine the limitations of these studies in accordance with the assumptions of the utilized methods.

SEARCH METHODS

The PubMed database was used to search for peer-reviewed original research articles using the terms 'Mendelian randomization endometriosis' and '"genetic correlation" endometriosis'. Additionally, a Google Scholar search using the terms '"endometriosis" "mendelian randomization" "genetic correlation"' was performed. All relevant publications (n = 21) published up until 7 October 2022 were included in this review. Upon compilation of all traits with published MR and/or genetic correlation with endometriosis, additional epidemiological and genetic information on their comorbidity with endometriosis was sourced by searching for the trait in conjunction with 'endometriosis' on Google Scholar.

OUTCOMES

The association between endometriosis and multiple pain, gynaecological, cancer, inflammatory, gastrointestinal, psychological, and anthropometric traits has been assessed using MR analysis and genetic correlation analysis. Genetic correlation analyses provide evidence that genetic factors contributing to endometriosis are shared with multiple traits: migraine, uterine fibroids, subtypes of ovarian cancer, melanoma, asthma, gastro-oesophageal reflux disease, gastritis/duodenitis, and depression, suggesting the involvement of multiple biological mechanisms in endometriosis. The assessment of causality with MR has revealed several potential causes (e.g. depression) and outcomes (e.g. ovarian cancer and uterine fibroids) of a genetic predisposition to endometriosis; however, interpretation of these results requires consideration of potential violations of the MR assumptions.

WIDER IMPLICATIONS

Genomic studies have demonstrated that there is a molecular basis for the co-occurrence of endometriosis with other traits. Dissection of this overlap has identified shared genes and pathways, which provide insight into the biology of endometriosis. Thoughtful MR studies are necessary to ascertain causality of the comorbidities of endometriosis. Given the significant diagnostic delay of endometriosis of 7-11 years, determining risk factors is necessary to aid diagnosis and reduce the disease burden. Identification of traits for which endometriosis is a risk factor is important for holistic treatment and counselling of the patient. The use of genomic data to disentangle the overlap of endometriosis with other traits has provided insights into the aetiology of endometriosis.

Genomic characterisation of the overlap of endometriosis with 76 comorbidities identifies pleiotropic and causal mechanisms underlying disease risk

Comorbid conditions can be driven by underlying pleiotropic and causal mechanisms that can provide insights into shared molecular and biological processes contributing to disease risk. Endometriosis is a chronic condition affecting one in nine women of reproductive age and poses many challenges including lengthy diagnostic delays and limited treatment efficacy owing to poor understanding of disease aetiology. To shed light on the underlying biological mechanisms and to identify potential risk factors, we examine the epidemiological and genomic relationship between endometriosis and its comorbidities. In the UK Biobank 292 ICD10 codes were epidemiologically correlated with endometriosis diagnosis, including gynaecological, immune, infection, pain, psychiatric, cancer, gastrointestinal, urinary, bone and cardiovascular traits. A subset of the identified comorbidities (n = 76) underwent follow-up genetic analysis. Whilst Mendelian randomisation suggested causality was not responsible for most comorbid relationships, 22 traits were genetically correlated with endometriosis, including pain, gynaecological and gastrointestinal traits, suggestive of a shared genetic background. Pleiotropic genetic variants and genes were identified using gene-based and colocalisation analysis. Shared genetic risk factors and potential target genes suggest a diverse collection of biological systems are involved in these comorbid relationships including coagulation factors, development of the female reproductive tract and cell proliferation. These findings highlight the diversity of traits with epidemiological and genomic overlap with endometriosis and implicate a key role for pleiotropy in the comorbid relationships.

Understanding endometriosis from an immunomicroenvironmental perspective

ABSTRACT

Endometriosis, a heterogeneous, inflammatory, and estrogen-dependent gynecological disease defined by the presence and growth of endometrial tissues outside the lining of the uterus, affects approximately 5-10% of reproductive-age women, causing chronic pelvic pain and reduced fertility. Although the etiology of endometriosis is still elusive, emerging evidence supports the idea that immune dysregulation can promote the survival and growth of retrograde endometrial debris. Peritoneal macrophages and natural killer (NK) cells exhibit deficient cytotoxicity in the endometriotic microenvironment, leading to inefficient eradication of refluxed endometrial fragments. In addition, the imbalance of T-cell subtypes results in aberrant cytokine production and chronic inflammation, which contribute to endometriosis development. Although it remains uncertain whether immune dysregulation represents an initial cause or merely a secondary enhancer of endometriosis, therapies targeting altered immune pathways exhibit satisfactory effects in preventing disease onset and progression. Here, we summarize the phenotypic and functional alterations of immune cells in the endometriotic microenvironment, focusing on their interactions with microbiota and endocrine and nervous systems, and how these interactions contribute to the etiology and symptomology of endometriosis.

The significance of immune microenvironment in patients with endometriosis

Endometriosis represents an estrogen-dependent disease of the female reproductive system and intra- and extraperitoneal regions, with chronic feature. Currently, immune cells, such as macrophages and lymphocytes, are considered to play a pivotal role in angiogenesis and invasion of endometriotic cells through matrix remodeling. Additionally, various studies have revealed the role of E-cadherin, β-catenin, along with steroid hormone receptors in endometriosis development. In this context, our study aimed to analyze the relationship between the cellular immune profile and E-cadherin, β-catenin, estrogen receptor alpha (ERα), and progesterone receptor (PR) immunoexpression in endometriosis tissues, along with an analysis of the possible association between serological parameters and immunohistochemical (IHC) markers. The study included 53 patients diagnosed with ovarian or cutaneous abdominal wall endometriosis, which have been investigated by routine histology, immunohistochemistry, and serum analysis. The IHC exam showed an increased density of cluster of differentiation (CD)4+ T-cells, CD8+ T-cells, and CD68+ macrophages, along with variable increased expressions of E-cadherin, β-catenin, ERα, and PR. Statistical analysis revealed an intense positive correlation between CD68 and PR expression (p<0.05), without any other statistically significant correlations between IHC markers or between IHC and serological markers. Our study supports that endometriosis is an immune-dependent disease characterized by an abnormal morphological profile of T-cells and macrophages in endometriotic implants. Our study provides additional data useful in the understanding the immune milieu of endometriosis in the context of its complex pathogenic molecular mechanism. Further research is needed to develop new immunological therapeutic approaches, like immune checkpoint inhibitors administration or T-cell-targeted immunotherapy in these patients.

Understanding Psychological Symptoms of Endometriosis from a Research Domain Criteria Perspective

Endometriosis is currently the second most common gynecological disease and is associated with severe pain, vegetative impairment, and infertility. In association, there are considerable psychological symptoms that limit the quality of life of those affected. In this narrative review, the Research Domain Criteria (RDoC) framework was utilized to display the different transdiagnostic processes involved in disease progression and maintenance in regard to psychosocial functioning. Using the RDoC framework, it becomes clear that immune/endocrinological dysregulation is interlocked with (pelvic) pain chronification processes and psychological symptoms such as depressive mood, loss of control, higher vigilance toward the onset or worsening of symptoms, social isolation, and catastrophizing. This paper will discuss and identify promising treatment approaches, in addition to medical care, as well as further research implications. Endometriosis can come with substantial psychosomatic and social burden, requiring more research to understand the interdependence of different factors involved in its chronic development pathway. However, it is already clear that standard care should be extended with multifaceted treatments addressing pain, as well as the psychological and social burden, in order to halt the cycle of aggravation of symptoms and to improve quality of life for patients.

Prolactin and pain of endometriosis

Women experience chronic pain more often than men with some pain conditions being specific to women while others are more prevalent in women. Prolactin, a neuropeptide hormone with higher serum levels in women, has recently been demonstrated in preclinical studies to sensitize nociceptive sensory neurons in a sexually dimorphic manner. Dysregulation of prolactin and prolactin receptors may be responsible for increased pain especially in female predominant conditions such as migraine, fibromyalgia, and pelvic pain. In this review, we focus on the role of prolactin in endometriosis, a condition characterized by pelvic pain and infertility that affects a large proportion of women during their reproductive age. We discuss the symptoms and pathology of endometriosis and discuss how different sources of prolactin secretion may contribute to this disease. We highlight our current understanding of prolactin-mediated mechanisms of nociceptor sensitization in females and how this mechanism may apply to endometriosis. Lastly, we report the results of a systematic review of clinical studies conducted by searching the PubMed and EMBASE databases to identify association between endometriosis and blood levels of prolactin. The results of this search strongly indicate that serum prolactin levels are increased in patients with endometriosis and support the possibility that high levels of prolactin may promote pelvic pain in these patients and increase vulnerability to other comorbid pain conditions likely by dysregulating prolactin receptor expression. Targeting of prolactin and prolactin receptors may improve management of pain associated with endometriosis.

A Rare Case of Complete Perforation of Endometrial Tissue Through the Mucosa of the Sigmoid Colon

Endometriosis is a disease that causes endometrial tissues to proliferate outside of the uterus. The condition is often attributed to estrogen imbalance and can lead to severe inflammation and bleeding, where it is believed that 10% of female patients experience this illness. Endometrial growth can occur in the ovaries, fallopian tubes, stomach, and gastrointestinal tract. Twelve percent of endometriosis cases can be seen in the intestines, with the rectosigmoid colon accounting for 72% of these cases. Patients with intestinal endometriosis may present with moderate symptoms, such as constipation, but they may experience more serious complications as well such as intestinal bleeding. Although the presence of endometrial tissue in the colon is already a rare phenomenon, it is even rarer for endometrial growth to perforate the entire mucosa of the sigmoid colon. A study in 2010 reported that only 21 of such cases have occurred since 1931. The patient in this case report had a gene (MUTYH) mutation that put her at risk for colorectal cancer, and she was ultimately treated with segmental resection of the sigmoid colon. The final pathology of the specimen revealed that the patient's lesion was endometrial growth. In this case report, we present a rare finding of endometrial tissue perforating through a patient's intestinal lumen, which was successfully treated with surgical intervention.

The Impact of Histone Modifications in Endometriosis Highlights New Therapeutic Opportunities

Endometriosis is a chronic disorder of the female reproductive system which afflicts a great number of women worldwide. Histone deacetylases (HDACs) prevent the relaxation of chromatin, thereby positively or negatively modulating gene transcription. The current review aims at studying the impact of histone modifications and their therapeutic targeting in endometriosis. In order to identify relevant studies, a literature review was conducted using the MEDLINE and LIVIVO databases. The current manuscript represents the most comprehensive, up-to-date review of the literature focusing on the particular role of HDACs and their inhibitors in the context of endometriosis. HDAC1, HDAC2, HDAC3, Sirtuin 1, and Sirtuin 3, are the five most studied HDAC enzymes which seem to, at least partly, influence the pathophysiology of endometriosis. Both well-established and novel HDACIs could possibly represent modern, efficacious anti-endometriotic drug agents. Altogether, histone modifications and their therapeutic targeting have been proven to have a strong impact on endometriosis.

Assessment of BMP7, SMAD4, and CDH1 Expression Profile and Regulatory miRNA-542-3p in Eutopic and Ectopic Endometrium of Women with Endometriosis

Alterations in the expression of numerous genes and the miRNAs that are recognized as their regulators in the endometrial cells of women with endometriosis may disrupt the intracellular signaling pathways associated with epithelial–mesenchymal transition (EMT). So far, the functional role of BMP7 in endometrial physiology has been confirmed, especially in the context of fertility, but the role of the activation of a specific mechanism operating through the BMP–SMAD–CDH1 axis in the formation of endometrial lesions remains unexplored. The aim of this study was to evaluate the expression profile of miR-542-3p and the EMT markers (BMP7, SMAD4, CDH1) in matched eutopic endometrium (EUE) and ectopic endometrium (ECE) samples from women with endometriosis in relation to healthy women. The levels of expression of the studied genes and miRNA in peripheral blood mononuclear cells (PBMCs) obtained from women diagnosed with endometriosis and those without the disease were also evaluated. Fifty-four patients (n = 54: with endometriosis—n = 29 and without endometriosis—n = 25) were included in the study. A comparative analysis of the relative mean expression values (RQ) of the studied mRNA and miRNA assessed by RT-qPCR demonstrated downregulation of BMP7, SMAD4, and CDH1 expression in ectopic lesions and upregulation in the eutopic endometrium compared with the control group. In the eutopic tissue of women with endometriosis, miR-542-3p expression was similar to that of the control but significantly lower than in endometrial lesions. We also confirmed a trend towards a negative correlation between miR-542-3p and BMP7 in ectopic tissue, and in PBMC, a significant negative correlation of miR-542-3p with further BMP signaling genes, i.e., SMAD4 and CDH1, was observed. These results indicate that the miRNA selected by us may be a potential negative regulator of BMP7-SMAD4-CDH1 signaling associated with EMT. The different patterns of BMP7, SMAD4, and CDH1 gene expression in ECE, EUE, and the control endometrium observed by us suggests the loss of the endometrial epithelium phenotype in women with endometriosis and demonstrates their involvement in the pathogenesis and pathomechanism of this disease.

Endometriosis-associated chronic pelvic pain

Endometriosis is a heterogeneous disease where neurogenic sensitization can lead to chronic pain within and beyond the pelvis. Coincident pain and comorbidities merit specific attention. We discuss the causes, comorbidities, and management of endometriosis-associated chronic pelvic pain, advocating for a multidisciplinary approach to develop more effective treatments.

Endometriosis leads to central nervous system-wide glial activation in a mouse model of endometriosis

BACKGROUND

Chronic pelvic pain (CPP) is a common symptom of endometriosis. Women with endometriosis are also at a high risk of suffering from anxiety, depression, and other psychological disorders. Recent studies indicate that endometriosis can affect the central nervous system (CNS). Changes in the functional activity of neurons, functional magnetic resonance imaging signals, and gene expression have been reported in the brains of rat and mouse models of endometriosis. The majority of the studies thus far have focused on neuronal changes, whereas changes in the glial cells in different brain regions have not been studied.

METHODS

Endometriosis was induced in female mice (45-day-old; n = 6-11/timepoint) by syngeneic transfer of donor uterine tissue into the peritoneal cavity of recipient animals. Brains, spines, and endometriotic lesions were collected for analysis at 4, 8, 16, and 32 days post-induction. Sham surgery mice were used as controls (n = 6/timepoint). The pain was assessed using behavioral tests. Using immunohistochemistry for microglia marker ionized calcium-binding adapter molecule-1 (IBA1) and machine learning "Weka trainable segmentation" plugin in Fiji, we evaluated the morphological changes in microglia in different brain regions. Changes in glial fibrillary acidic protein (GFAP) for astrocytes, tumor necrosis factor (TNF), and interleukin-6 (IL6) were also evaluated.

RESULTS

We observed an increase in microglial soma size in the cortex, hippocampus, thalamus, and hypothalamus of mice with endometriosis compared to sham controls on days 8, 16, and 32. The percentage of IBA1 and GFAP-positive area was increased in the cortex, hippocampus, thalamus, and hypothalamus in mice with endometriosis compared to sham controls on day 16. The number of microglia and astrocytes did not differ between endometriosis and sham control groups. We observed increased TNF and IL6 expression when expression levels from all brain regions were combined. Mice with endometriosis displayed reduced burrowing behavior and hyperalgesia in the abdomen and hind-paw.

CONCLUSION

We believe this is the first report of central nervous system-wide glial activation in a mouse model of endometriosis. These results have significant implications for understanding chronic pain associated with endometriosis and other issues such as anxiety and depression in women with endometriosis.

Esketamine in the treatment of chronic endometriosis-induced pain: a case report

Introduction:

The pathophysiology of endometriosis-induced pain is complex and current pain management is often inadequate. As a consequence, the quality of life of endometriosis patients is reduced due to persistent and often recurrent severe pain, affecting emotional well-being.

Case description:

In this case report, we present a 28-year-old patient with deep endometriosis and severe pain resistant to conventional therapy, who experienced, after an 8-h infusion with esketamine, no pain symptoms for 8 weeks.

Discussion:

Current treatment options to suppress chronic pain symptoms in patients with (deep) endometriosis are often inadequate. Esketamine targets key components of the condition (inflammation, pain, depression), but the use of this drug in the treatment of chronic pain due to endometriosis has not been reported yet. Future trials are necessary to assess the effect of esketamine in the treatment of chronic pain due to endometriosis.

Conclusion:

This case report highlights the potential of esketamine infusion therapy in the treatment of endometriosis patients with persistent pain despite conventional therapy.

The burden of Chronic Pelvic Pain (CPP): Costs and quality of life of women and men with CPP treated in outpatient referral centers

INTRODUCTION

Chronic Pelvic Pain (CPP) is a complex, multifaceted condition that affects both women and men. There is limited literature on the cost utilization the healthcare system and CPP patients incur. The purpose of this analysis is to characterize the overall healthcare utilization, cost burden, and quality-of-life restrictions experienced by CPP patients using data from an outpatient pelvic rehabilitation practice.

METHODS

Healthcare utilization data was gathered by systematically reviewing and analyzing data from new patient visit progress notes stored in the clinic's electronic health records (EHR). We obtained in-network costs by using the FAIR Health Consumer online database. Overall costs were then calculated as the utilization times the per-unit costs from the FAIR database. Additionally, data on patients' visual analogue scale (VAS), absenteeism, presenteeism emergency room visits, usage of common pain medications, use of diagnostics, and participation in common treatment modalities was gathered.

RESULTS

Data from 607 patients was used. The overall cost burden per patient for all surgeries combined was $15,750 for in-network services. The cost burden for diagnostics was $5,264.22 and treatments was $8,937 per patient for in-network treatments.

CONCLUSION

Chronic Pelvic Pain was found to have a large cost burden of $29,951 for in-network services which includes treatments, diagnostics, and surgeries. This analysis sets the stage for future investigations involving data on costs of medications that patients have tried prior to presenting to us and costs associated with work hours lost.

Atherosclerosis and Endometriosis: The Role of Diet and Oxidative Stress in a Gender-Specific Disorder

Background: Accelerated atherosclerosis in patients with endometriosis has been hypothesised, and lifestyle improvement might control cardiovascular risk. We explored cardiometabolic markers and oxidative stress and evaluated the effects of the Mediterranean Diet (MD) in modulating these markers. Methods: In this prospective study, we included 35 women with endometriosis. At baseline (T0) and after 3 (T1) and 6 (T2) months from the start of the diet, we investigated cardiometabolic parameters, lifestyle and oxidative stress. Results: After a 3-month intervention with MD, we observed a significant reduction in total cholesterol (p = 0.01) and LDL-c (p = 0.003). We observed at T1 an increase in B12 and E vitamins, folate and zinc. After 6 months, zinc (p = 0.04) and folate (p = 0.08) increased in comparison to T0. A reduction in homocysteine from T0 to T1 (p = 0.01) was found. After 3 months, an increase in Rapid Assessment of Physical Activity tool 1 (RAPA) (p < 0.001) and RAPA 2 was observed (p = 0.009). We observed high levels of oxidative stress markers at baseline. After 6 months of MD, a significant improvement in lymphocyte Reactive Oxygen Species (ROS) (p < 0.001) and total antioxidant capacity was observed (p = 0.02). Conclusions: The improvement of lifestyle, and in particular the Mediterranean dietary intervention, allowed the improvement of the metabolic and oxidative profile and overall health-related quality of life.

Endometriosis and Opioid Receptors: Are Opioids a Possible/Promising Treatment for Endometriosis?

Endometriosis (EM), defined as the presence of endometrial-like tissue with surrounding smooth muscle cells outside the uterus, is a disregarded gynecological disease reported to affect 6-10% of women of reproductive age, with 30-50% of them suffering from chronic pelvic pain and infertility. Since the exact pathogenic mechanisms of EM are still unclear, no curative therapy is available. As pain is an important factor in EM, optimal analgesia should be sought, which to date has been treated primarily with non-steroidal anti-inflammatory drugs (NSAIDs), metamizole or, in extreme cases, opioids. Here, we review the pain therapy options, the mechanisms of pain development in EM, the endogenous opioid system and pain, as well as the opioid receptors and EM-associated pain. We also explore the drug abuse and addiction to opioids and the possible use of NOP receptors in terms of analgesia and improved tolerability as a target for EM-associated pain treatment. Emerging evidence has shown a promising functional profile of bifunctional NOP/MOP partial agonists as safe and nonaddictive analgesics. However, until now, the role of NOP receptors in EM has not been investigated. This review offers a thought which still needs further investigation but may provide potential options for relieving EM-associated pain.

UPLC-Q-TOF/MS Based Plasma Metabolomics for Identification of Paeonol's Metabolic Target in Endometriosis

Endometriosis is a common gynecological illness in women of reproductive age that significantly decreases life quality and fertility. Paeonol has been shown to play an important part in endometriosis treatments. Understanding the mechanism is critical for treating endometriosis. In this study, autologous transplantation combined with a 28 day ice water bath was used to create a rat model of endometriosis with cold clotting and blood stagnation. The levels of estradiol and progesterone in plasma were detected by ELISA, and the pathological changes of ectopic endometrial tissue were examined by H&E staining, which proved the efficacy of paeonol. For metabolomic analysis of plasma samples, UPLC-Q/TOF-MS was combined with multivariate statistical analysis to identify the influence of paeonol on small molecule metabolites relevant to endometriosis. Finally, the key targets were screened using a combination of network pharmacology and molecular docking approaches. The results showed that the pathological indexes of rats were improved and returned to normal levels after treatment with paeonol, which was the basis for confirming the efficacy of paeonol. Metabolomics results identified 13 potential biomarkers, and paeonol callbacks 7 of them, involving six metabolic pathways. Finally, four key genes were found for paeonol therapy of endometriosis, and the results of molecular docking revealed a significant interaction between paeonol and the four key genes. This study was successful in establishing a rat model of endometriosis with cold coagulation and blood stagnation. GCH1, RPL8, PKLR, and MAOA were the key targets of paeonol in the treatment of endometriosis. It is also demonstrated that metabolomic techniques give the potential and environment for comprehensively understanding drug onset processes.

Epidemiologic and Genetic Associations of Endometriosis With Depression, Anxiety, and Eating Disorders

IMPORTANCE

Endometriosis is a common chronic gynecologic pathology with a large negative impact on women's health. Beyond severe physical symptoms, endometriosis is also associated with several psychiatric comorbidities, including depression and anxiety.

OBJECTIVE

To investigate whether pleiotropy contributes to the association of endometriosis with depression, anxiety, and eating disorders.

DESIGN, SETTING, AND PARTICIPANTS

This genetic association study was performed between September 13, 2021, and June 24, 2022, in 202 276 unrelated female participants. Genotypic and phenotypic information from the UK Biobank was combined with genome-wide association statistics available from the Psychiatric Genomics Consortium (11 countries), the Million Veteran Program (US), the FinnGen study (Finland), and the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) consortium (5 countries).

MAIN OUTCOMES AND MEASURES

The main outcomes were the phenotypic and genetic associations of endometriosis with anxiety, depression, and eating disorders.

RESULTS

A total of 8276 women with endometriosis (mean [SD] age, 53.1 [7.9] years) and 194 000 female controls (mean [SD] age, 56.7 [7.9] years) were included in the study. In a multivariate regression analysis accounting for age, body mass index, socioeconomic status, chronic pain-related phenotypes, irritable bowel syndrome, and psychiatric comorbidities, endometriosis was associated with increased odds of depression (odds ratio [OR], 3.61; 95% CI, 3.32-3.92), eating disorders (OR, 2.94; 95% CI, 1.96-4.41), and anxiety (OR, 2.61; 95% CI, 2.30-2.97). These associations were supported by consistent genetic correlations (rg) (depression rg, 0.36, P = 1.5 × 10-9; anxiety rg, 0.33, P = 1.17 × 10-5; and eating disorders rg, 0.61, P = .02). With the application of a 1-sample mendelian randomization, the genetic liabilities to depression and anxiety were associated with increased odds of endometriosis (depression: OR, 1.09; 95% CI, 1.08-1.11; anxiety: OR, 1.39; 95% CI, 1.13-1.65). A genome-wide analysis of pleiotropic associations shared between endometriosis and psychiatric disorders identified 1 locus, DGKB rs12666606, with evidence of pleiotropy between endometriosis and depression after multiple testing correction (z = -9.46 for endometriosis, z = 8.10 for depression, P = 5.56 × 10-8; false discovery rate q = 4.95 × 10-4).

CONCLUSIONS AND RELEVANCE

These findings highlight that endometriosis is associated with women's mental health through pleiotropic mechanisms. To our knowledge, this is the first large-scale study to provide genetic and phenotypic evidence of the processes underlying the psychiatric comorbidities of endometriosis.

Pattern-recognition receptors in endometriosis: A narrative review

Endometriosis is closely associated with ectopic focal inflammation and immunosuppressive microenvironment. Multiple types of pattern recognition receptors (PRRs) are present in the innate immune system, which are able to detect pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) in both intracellular and external environments. However, the exact role of PRRs in endometriosis and the underlying molecular mechanism are unclear. PRRs are necessary for the innate immune system to identify and destroy invasive foreign infectious agents. Mammals mainly have two types of microbial recognition systems. The first one consists of the membrane-bound receptors, such as toll-like receptors (TLRs), which recognize extracellular microorganisms and activate intracellular signals to stimulate immune responses. The second one consists of the intracellular PRRs, including nod-like receptors (NLRs) and antiviral proteins retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA-5) with helix enzyme domain. In this review, we mainly focus on the key role of PRRs in the pathological processes associated with endometriosis. PRRs recognize PAMPs and can distinguish pathogenic microorganisms from self, triggering receptor ligand reaction followed by the stimulation of host immune response. Activated immune response promotes the transmission of microbial infection signals to the cells. As endometriosis is characterized by dysregulated inflammation and immune response, PRRs may potentially be involved in the activation of endometriosis-associated inflammation and immune disorders. Toll-like receptor 2 (TLR2), toll-like receptor 3 (TLR3), toll-like receptor 4 (TLR4), nod-like receptor family caspase activation and recruitment domain (CARD) domain containing 5 (NLRC5), nod-like receptor family pyrin domain containing 3 (NLRP3), and c-type lectin receptors (CLRs) play essential roles in endometriosis development by regulating immune and inflammatory responses. Absent in melanoma 2 (AIM2)-like receptors (ALRs) and retinoic acid-inducible gene I-like receptors (RLRs) may be involved in the activation of endometriosis-associated immune and inflammation disorders. PRRs, especially TLRs, may serve as potential therapeutic targets for alleviating pain in endometriosis patients. PRRs and their ligands interact with the innate immune system to enhance inflammation in the stromal cells during endometriosis. Thus, targeting PRRs and their new synthetic ligands may provide new therapeutic options for treating endometriosis.

Potential link between the nerve injury-induced protein (Ninjurin) and the pathogenesis of endometriosis

Endometriosis remains a widespread but severe gynecological disease in women of reproductive age, with an unknown etiology and few treatment choices. The menstrual reflux theory is largely accepted as the underlying etiology but does not explain the morbidity or unpleasant pain sensations of endometriosis. The neurological and immune systems are both involved in pain mechanisms of endometriosis, and interlinked through a complex combination of cytokines and neurotransmitters. Numerous pieces of evidence suggest that the nerve injury-inducible protein, Ninjurin, is actively expressed in endometriosis lesions, which contributes to the etiology and development of endometriosis. It may be explored in the future as a novel therapeutic target. The aim of the present review was to elucidate the multifaceted role of Ninjurin. Furthermore, we summarize the association of Ninjurin with the pain mechanism of endometriosis and outline the future research directions. A novel therapeutic pathway can be discovered based on the potential pathogenic variables.

Understanding the Female Physical Examination in Patients with Chronic Pelvic and Perineal Pain

(1) Background: The objective was to compare the exploration of chronic pelvic pain syndrome (CPPS) patients in different locations and establish the role of physical examination in CPPS patients. (2) Methods: We reviewed clinical data from 107 female patients with CPPS unresponsive to conventional therapies at Puerta de Hierro University Hospital Madrid, Spain, from May 2018 to June 2022. Patients were classified into three groups: (a) pelvic pain; (b) anorectal pain; or (c) vulvar/perineal pain. (3) Results: Although the demographics of patients with CPPS were different, their physical examinations were strikingly similar. Our study observed a comorbidity rate of 36% and 79% of central sensitization of pain. Seventy-one percent of patients had vulvar allodynia/hyperalgesia. Pain on examination was identified in any pelvic floor muscle, in any pelvic girdle structure, and neuropathic pain in 98%, 96%, and 89%, respectively. Patients with vulvar and perineal pain were more different from the other groups; these patients were younger and had fewer comorbidities and less central sensitization, less anorectal pain, more pain during intercourse, and greater nulliparity (p = 0.022; p = 0.040; p = 0.048; p = 0.000; p = 0.006; p = 0.005). (4) Conclusions: The findings of this study are related to the understanding of the pathophysiology of CPPS. The physical examination confirms the central sensitization of female patients with CPPS, helps us to determine the therapeutic management of the patient, and can be considered as a prognostic factor of the disease.

Progestins in the symptomatic management of endometriosis: a meta-analysis on their effectiveness and safety

BACKGROUND

Endometriosis is a complex chronic disease that affects approximately 10% of women of reproductive age worldwide and commonly presents with pelvic pain and infertility.

METHOD & OUTCOME MEASURES

A systematic review of the literature was carried out using the databases Pubmed, Scopus, Cochrane and ClinicalTrials.gov in women with a confirmed laparoscopic diagnosis of endometriosis receiving progestins to determine a reduction in pain symptoms and the occurrence of adverse effects.

RESULTS

Eighteen studies were included in the meta-analysis. Progestins improved painful symptoms compared to placebo (SMD = -0.61, 95% CI (-0.77, -0.45), P < 0.00001) with no comparable differences between the type of progestin. After median study durations of 6-12 months, the median discontinuation rate due to adverse effects was 0.3% (range: 0 - 37.1%) with mild adverse effects reported.

CONCLUSION

The meta-analysis revealed that pain improvement significantly increased with the use of progestins with low adverse effects.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021285026.

Effect of Antioxidant Supplementation on Endometriosis-Related Pain: A Systematic Review

PURPOSE OF REVIEW

This study was conducted to determine the effects of antioxidant supplementation on endometriosis-related chronic pelvic pain, dysmenorrhea, and dyspareunia.

METHODS

PubMed/MEDLINE, Scopus, and Cochrane Library databases and the Google Scholar search engine were searched from early 2012 to 2022 using appropriate keywords for clinical trials receiving antioxidant supplements and reporting endometriosis-related pelvic pain (PROSPERO registration number CRD42022318924). The qualities of the included studies were evaluated using the Joanna Briggs Institute (JBI) Checklists Critical Appraisal Tools and the National Institutes of Health (NIH) quality assessment tool for before-after (Pre-Post) study with no control group. This systematic review was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guideline.

RESULTS

In this systematic review, 8 studies (5 RCTs and 3 non-comparative trials) published in 2012-2022 were included.

CONCLUSIONS

The studies we included showed promising results in the use of antioxidants in endometriosis-related pain. However, many scientific studies are needed for clear statements.

Aged garlic extract as a potential prophylactic to reduce the progression of endometriosis and associated pain burden

Endometriosis is a complex and potentially debilitating condition that has major impact on quality of life. There is emerging evidence that biological compounds found in garlic (Allium sativum) may be effective for attenuating endometrial pain. Suggested mechanisms for efficacy include modulation of inflammation and potent antioxidant effects. Aged-garlic-extract (AGE) is a centuries old process describing ethanolic extracts of garlic bulbs for 12-20 months. The AGE formulation realised contains a complex array of stabilised biologics with significant immunomodulatory effects relevant to inflammatory conditions. This perspective article puts forward a hypothesis that AGE should be considered as a prophylactic to manage endometrial pain.

Altered anterior insula functional connectivity in adolescent and young women with endometriosis-associated pain: Pilot resting-state fMRI study

BACKGROUND

Endometriosis is the leading cause of chronic pelvic pain. Alterations in brain functional connectivity have been reported in adult women with endometriosis-associated pain (EAP), however, it is still unknown if similar patterns of changes exist in adolescents.

METHODS

In this pilot study, resting-state fMRI scans were obtained from 11 adolescent and young women with EAP and 14 healthy female controls. Using a seed-to-voxel approach, we investigated functional connectivity between the anterior insula, medial prefrontal cortex, and the rest of the brain. Furthermore, we explored whether potential functional connectivity differences were correlated with clinical characteristics including disease duration, pain intensity, and different psychosocial factors (pain catastrophizing, fear of pain, functional disability, anxiety, and depression).

RESULTS

Our findings revealed that patients with EAP demonstrated significantly decreased connectivity between the right anterior insula and two clusters: one in the right cerebellum, and one in the left middle frontal gyrus compared to controls. Additionally, functional connectivity between the right anterior insula and the right cerebellum was positively associated with pain intensity levels. In patients with EAP, brain changes were also correlated with state anxiety and fear of pain.

CONCLUSIONS

Our results are relevant not only for understanding the brain characteristics underlying EAP at a younger age, but also in enhancing future pain treatment efforts by supporting the involvement of the central nervous system in endometriosis.

Unveil the pain of endometriosis: from the perspective of the nervous system

Endometriosis is a chronic inflammatory disease with pelvic pain and uncharacteristic accompanying symptoms. Endometriosis-associated pain often persists despite treatment of the disease, thus it brings a deleterious impact on their personal lives as well as imposing a substantial economic burden on them. At present, mechanisms underlie endometriosis-associated pain including inflammatory reaction, injury, aberrant blood vessels and the morphological and functional anomaly of the peripheral and central nervous systems. The nerve endings are influenced by the physical and chemical factors surrounding the lesion, via afferent nerve to the posterior root of the spinal nerve, then to the specific cerebral cortex involved in nociception. However, our understanding of the aetiology and mechanism of this complex pain process caused by endometriosis remains incomplete. Identifying the pathogenesis of endometriosis is crucial to disease management, offering proper treatment, and helping patients to seek novel targets for the maintenance and contributors of chronic pain. The main aim of this review is to focus on every possible mechanism of pain related to endometriosis in both peripheral and central nervous systems, and to present related mechanisms of action from the interaction between peripheral lesions and nerves to the changes in transmission of pain, resulting in hyperalgesia and the corresponding alterations in cerebral cortex and brain metabolism.

Transvaginal ultrasound evaluation of the pelvis and symptoms after laparoscopic partial cystectomy for bladder endometriosis

Objective:

To evaluate transvaginal sonography (TVS) findings after laparoscopic partial cystectomy for bladder endometriosis and to correlate postsurgical ultrasound findings with symptoms.

Material and Methods:

A retrospective study including women who underwent laparoscopic partial cystectomy for bladder endometriosis. Within 12 months after surgery, TVS examination was conducted in all patients to evaluate the bladder morphology, and the presence of any postsurgical sonographic findings of the pelvis. Painful symptoms were assessed using a visual analogue scale.

Results:

A total of 40 women were included. At the follow-up visit, 25 patients were receiving medical treatment while 15 had declined post-surgical therapy and had tried to conceive. The presence of bladder deep-infiltrating endometriosis (DIE) was found in nine (22.5%), fibrotic thickening of the bladder wall was found in 15 (37.5%), and normal bladder morphology was observed in 16 (40%). There was a correlation between anterior adenomyosis and bladder DIE, and fibrotic thickening of the bladder. Patients with TVS signs of bladder DIE and anterior adenomyosis suffered more dysmenorrhea and dysuria than patients with normal bladder.

Conclusion:

Post-operative TVS can detect the alteration of pelvis and could explain the causes of the persistence of symptoms.

A syngeneic inoculation mouse model of endometriosis that develops multiple comorbid visceral and cutaneous pain like behaviours

ABSTRACT

Endometriosis is a chronic and debilitating condition, commonly characterised by chronic pelvic pain (CPP) and infertility. Chronic pelvic pain can be experienced across multiple pelvic organs, with comorbidities commonly effecting the bowel, bladder, and vagina. Despite research efforts into endometriosis pathophysiology, little is known about how endometriosis induces CPP, and as such, therapeutic interventions are lacking. The aim of this study was to characterise a syngeneic mouse model of endometriosis that mimics naturally occurring retrograde menstruation, thought to precede endometriosis development in patients, and determine whether these mice exhibit signs of CPP and altered behaviour. We characterised the development of endometriosis over 10 weeks following uterine tissue inoculation, measured in vivo and ex vivo hypersensitivity to mechanical stimuli across multiple visceral organs, and assessed alterations in animal spontaneous behaviour. We confirmed that inoculated uterine horn tissue formed into endometriosis lesions throughout the peritoneal cavity, with significant growth by 8 to 10 weeks post inoculation. Additionally, we found that mice with fully developed endometriosis displayed hypersensitivity evoked by (1) vaginal distension, (2) colorectal distension, (3) bladder distension, and (4) cutaneous thermal stimulation, compared to their sham counterparts. Moreover, endometriosis mice displayed alterations in spontaneous behaviour indicative of (5) altered bladder function and (6) anxiety. This model creates a foundation for mechanistical studies into the diffuse CPP associated with endometriosis and the development of targeted therapeutic interventions to improve the quality of life of women with endometriosis.

Single-cell analysis of endometriosis reveals a coordinated transcriptional programme driving immunotolerance and angiogenesis across eutopic and ectopic tissues

Endometriosis is characterized by the growth of endometrial-like tissue outside the uterus. It affects many women during their reproductive age, causing years of pelvic pain and potential infertility. Its pathophysiology remains largely unknown, which limits early diagnosis and treatment. We characterized peritoneal and ovarian lesions at single-cell transcriptome resolution and compared them to matched eutopic endometrium, unaffected endometrium and organoids derived from these tissues, generating data on over 122,000 cells across 14 individuals. We spatially localized many of the cell types using imaging mass cytometry. We identify a perivascular mural cell specific to the peritoneal lesions, with dual roles in angiogenesis promotion and immune cell trafficking. We define an immunotolerant peritoneal niche, fundamental differences in eutopic endometrium and between lesion microenvironments and an unreported progenitor-like epithelial cell subpopulation. Altogether, this study provides a holistic view of the endometriosis microenvironment that represents a comprehensive cell atlas of the disease in individuals undergoing hormonal treatment, providing essential information for future therapeutics and diagnostics.

Review article: diagnostic and therapeutic approach to persistent abdominal pain beyond irritable bowel syndrome

BACKGROUND

Persistent abdominal pain (PAP) poses substantial challenges to patients, physicians and healthcare systems. The possible aetiologies of PAP vary widely across organ systems, which leads to extensive and repetitive diagnostic testing that often fails to provide satisfactory answers. As a result, widely recognised functional disorders of the gut-brain interaction, such as irritable bowel syndrome and functional dyspepsia, are often diagnosed in patients with PAP. However, there are a number of less well-known differential diagnoses that deserve consideration.

AIM

To provide a comprehensive update on causes of PAP that are relatively rare in occurrence.

METHODS

A literature review on the diagnosis and management of some less well-known causes of PAP.

RESULTS

Specific algorithms for the diagnostic work-up of PAP do not exist. Instead, appropriate investigations tailored to patient medical history and physical examination findings should be made on a case-by-case basis. After a definitive diagnosis has been reached, some causes of PAP can be effectively treated using established approaches. Other causes are more complex and may benefit from a multidisciplinary approach involving gastroenterologists, pain specialists, psychologists and physiotherapists. This list is inclusive but not exhaustive of all the rare or less well-known diseases potentially associated with PAP.

CONCLUSIONS

Persistent abdominal pain (PAP) is a challenging condition to diagnose and treat. Many patients undergo repeated diagnostic testing and treatment, including surgery, without achieving symptom relief. Increasing physician awareness of the various causes of PAP, especially of rare diseases that are less well known, may improve patient outcomes.

Targeting Oxidative Stress Involved in Endometriosis and Its Pain

Endometriosis is a common gynecological disorder seen in women and is characterized by chronic pelvic pain and infertility. This disorder is becoming more prevalent with increased morbidity. The etiology of endometriosis remains to be fully elucidated, which will lead to improved therapeutic options. In this review, we will evaluate the biochemical mechanisms leading to oxidative stress and their implication in the pathophysiology of endometriosis, as well as potential treatments that target these processes. A comprehensive exploration of previous research revealed that endometriosis is associated with elevated reactive oxygen species and oxidation products, decreased antioxidants and detoxification enzymes, and dysregulated iron metabolism. High levels of oxidative stress contributed to inflammation, extracellular matrix degradation, angiogenesis, and cell proliferation, which may explain its role in endometriosis. Endometriosis-associated pain was attributed to neurogenic inflammation and a feed-forward mechanism involving macrophages, pro-inflammatory cytokines, and pain-inducing prostaglandins. N-acetylcysteine, curcumin, melatonin, and combined vitamin C and E supplementation displayed promising results for the treatment of endometriosis, but further research is needed for their use in this population.

Endometriosis and irritable bowel syndrome: A systematic review and meta-analyses

Objective

To estimate the pooled odds ratio of endometriosis and irritable bowel syndrome, and to estimate the pooled prevalence of irritable bowel syndrome in patients with endometriosis.

Data sources

Using Cochrane Library, MEDLINE, Science Direct, ClinicalTrials.gov, Web of Science, and CINAHL, we conducted a systematic literature search through October 2021, using the key terms “endometriosis” and “irritable bowel syndrome.” Articles had to be published in English or Spanish. No restriction on geographical location was applied.

Methods of study selection

The following eligibility criteria were applied: full-text original articles; human studies; studies that investigated the association between endometriosis and irritable bowel syndrome. Two investigators screened and reviewed the studies. A total of 1,776 studies were identified in 6 separate databases. After screening and applying the eligibility criteria, a total of 17 studies were included for analyses. The meta-analysis of association between endometriosis and irritable bowel syndrome included 11 studies, and the meta-analysis on the prevalence of irritable bowel syndrome in endometriosis included 6 studies.

Tabulation, integration, and results

Overall 96,119 subjects were included in the main meta-analysis (11 studies) for endometriosis and irritable bowel syndrome, with 18,887 endometriosis patients and 77,171 controls. The odds of irritable bowel syndrome were approximately 3 times higher among patients with endometriosis compared with healthy controls (odds ratio 2.97; 95% confidence interval, 2.17 – 4.06). Similar results were obtained after subgroup analyses by endometriosis diagnosis, irritable bowel syndrome diagnostic criteria, and Newcastle-Ottawa Scale scores. Six studies reported prevalence rates of irritable bowel syndrome in women with endometriosis, ranging from 10.6 to 52%. The pooled prevalence of irritable bowel syndrome in women with endometriosis was 23.4% (95% confidence interval, 9.7 – 37.2).

Conclusion

Patients with endometriosis have an approximately threefold increased risk of developing irritable bowel syndrome. Development and recent update of Rome criteria has evolved the diagnosis of IBS, potential bias should still be considered as there are no specific tests available for diagnosis.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/displa y_record.php?ID=CRD42018080611], identifier [CRD42018080611].

Mediating Pain: Navigating Endometriosis on Social Media

With the rise of social media, many people with endometriosis have turned to platforms such as Facebook and Instagram in the face of lacking care. This qualitative study focuses on why and how people with endometriosis use these platforms. Despite the risks of misinformation and conflict on social media, the results of this research show that many people with endometriosis find these spaces beneficial, particularly for information sharing, social support, representation, and advocacy practices around endometriosis. Using data collected from surveys and interviews, this study reveals that people with endometriosis often use social media to understand, experiment with, and navigate their symptoms and that these efforts deserve recognition by endometriosis researchers and practitioners. This article proposes that, in order to improve future patient-practitioner and patient-researcher relationships for endometriosis, we must understand, not dismiss, the social media practices of those with endometriosis. By understanding how and why patients turn to social media, clinicians and researchers can build toward more patient-oriented futures.

Inflammation-mediated macrophage polarization induces TRPV1/TRPA1 heteromers in endometriosis

Chronic pelvic pain (CPP) and infertility are the common characteristics of endometriosis. Macrophages and related inflammation play important roles in endometriosis pain. TRPV1 and TRPA1 form a heteromeric channel which is related to endometriosis pain. In the present study, the inflammation-mediated macrophage polarization along with TRPV1/TRPA1 heteromers in endometriosis was investigated in vivo and in vitro. Macrophage polarization and TRPV1/TRPA1 heteromers in endometriosis tissue of patients were assayed, and was further investigated in endometriosis mice by co-culturing macrophages derived from mice in different groups with human endometrium cells. Our results indicated that macrophage polarization, as CD86 and CD206 positive macrophages, were accompanied by TRPV1/TRPA1 heteromers in endometriosis tissues of patients with pain. Inflammatory factors in peritoneal lavage fluid and serum of mice were correlated with TRPV1/TRPA1 expression in endometriosis tissues of mice as well as macrophage polarization which tended to be consistent with TRPV1/TRPA1 heteromers in endometriosis tissue. Moreover, macrophage polarization in enterocoelia induced ectopic endometrial cells migration with the increase in TRPV1/TRPA1 heteromers. Our results suggest that endometriosis-induced celiac inflammation might mediate macrophage polarization along with the increase of TRPV1/TRPA1 heteromers, which may play a key role in endometriosis pain.

Internet-based cognitive behavioral therapy for improving health-related quality of life in patients with endometriosis: study protocol for a randomized controlled trial

BACKGROUND

The trial investigates the efficacy of internet-based cognitive behavioral therapy (iCBT) in improving health-related QoL in patients with endometriosis, which is a chronic gynecological condition affecting up to 15% of people with female-assigned reproductive organs. Endometriosis is stress-related and comes with various physical symptoms such as pelvic pain and infertility. It has a substantial impact on health-related quality of life (QoL), and mind-body interventions seem promising in reducing the psychological burden.

METHODS

This is a monocentric randomized-controlled trial recruiting 120 patients with endometriosis. The intervention consists of eight iCBT modules focusing on psychoeducation, cognitive restructuring, pacing, and emotion regulation. Participants will receive written feedback from a trained therapist weekly. The comparator is a waitlist control group. All participants will be followed up 3 months after the intervention, and the intervention group will additionally be followed up 12 months after the intervention. Trial participants will not be blinded to the allocated trial arm. Primary outcome measures are endometriosis-related QoL, pain, and pain-related disability. Secondary outcomes include coping, illness representations, and psychological flexibility. Statistical analyses will be performed following intention-to-treat principles.

DISCUSSION

This randomized-controlled trial is the first trial to test the efficacy of iCBT for improving endometriosis-related QoL. Potential predictor variables and key mechanisms in treatment will be investigated to enable further progression in medical and psychological care for patients with endometriosis.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT05098444 Registered on October 28, 2021.

Communicating Endometriosis Pain in France and Australia: An Interview Study

Endometriosis is characterized by persistent, fluctuating pain associated with menstruation, a biological function which is socially invisible. The degree and quality of pain cannot easily be measured, observed, or documented. Difficulties in communicating pain pose particular challenges when seeking diagnosis and support from health professionals. In this paper we explore the experiences and characterization of pain by thirteen Australian and thirteen French women with endometriosis. Data were collected through semi-structured interviews using a life-history approach to illness symptoms, diagnosis and treatment. We explore the experiences of women with endometriosis in two phases: from onset of symptoms to seeking advice from a clinician, and from first consulting a clinician to receiving a diagnosis. On average, initial pain symptoms were identified 2.1 years before consulting a health practitioner, after which women reported pain symptoms 8.5 years prior to diagnosis; that is, the time between consulting a clinician and receiving a diagnosis was almost four times the period between experiencing symptoms and consulting a doctor. Pain was often “made real” to doctors by findings consistent with endometriosis on ultrasound and MRI, mostly used in France, or laparoscopy, the predominant diagnostic tool in Australia. No woman described her practitioner using standardized pain assessment tools. Thus, the validation of pain relies largely on disease visibility and the clinician-classified degree of severity rather than self-reported grades of pain or impact on activities of daily living. The invisible and enigmatic pain of this chronic women's disease remains difficult to communicate to doctors, and the recognition of severe pain is often key to timely diagnostic procedures. Clinicians need to be more proactive about severe pain related to menstruation, taking into consideration women's individual circumstances, and maintain a high index of suspicion of underlying endometriosis as a condition characterized primarily by pain.

Endometriosis pain and epithelial neutrophil activating peptide-78 levels

Endometriosis is a chronic gynecological disorder involved in the pathogenesis of chronic pelvic pain, based on a probable up regulation of the inflammatory system. The objective of the study is to investigate the peritoneal and serum levels of ENA-78 with the severity of endometriosis symptoms (dysmenorrhea, chronic pelvic pain and dyspareunia) using the visual analogue scale (VAS). This is a prospective case–control study that included 53 symptomatic women with evidence of endometriosis and 53 age-matched controls who underwent elective laparoscopic surgery for benign diseases. The concentration of ENA-78 was assessed in blood and peritoneal fluid samples in the follicular phase. In peritoneal fluid and plasma, the concentration of ENA-78 was significantly higher in cases than in controls (p < 0.001). A significant correlation was observed between peritoneal fluid ENA-78 levels and the severity of dysmenorrhea (Spearman Rho = 0.237; p = 0.014), and chronic pelvic pain (Spearman Rho = 0.220; p = 0.022) in endometriosis patients. Plasma levels ENA-78 showed a significant correlation with the severity (VAS score) of chronic pelvic pain (Spearman Rho = 0.270, p = 0.005 for cases), though a weak correlation was evident between plasma levels of ENA-78 and severity of dysmenorrhea (Spearman Rho = 0.083, p = 0.399 for cases). In conclusion, chronic pelvic pain in endometriosis is caused by changes of local and systemic activated chemokine patterns. These modifications involve the relationship between pro-inflammatory, angiogenic and angiostatic chemokines that modulate the severity of endometriosis associated symptoms.

Guanylate cyclase-C agonists as peripherally acting treatments of chronic visceral pain

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder characterized by abdominal pain and altered bowel habit that affects ~11% of the global population. Over the past decade, preclinical and clinical studies have revealed a variety of novel mechanisms relating to the visceral analgesic effects of guanylate cyclase-C (GC-C) agonists. Here we discuss the mechanisms by which GC-C agonists target the GC-C/cyclic guanosine-3',5'-monophosphate (cGMP) pathway, resulting in visceral analgesia as well as clinically relevant relief of abdominal pain and other sensations in IBS patients. Due to the preponderance of evidence we focus on linaclotide, a 14-amino acid GC-C agonist with very low oral bioavailability that acts within the gut. Collectively, the weight of experimental and clinical evidence supports the concept that GC-C agonists act as peripherally acting visceral analgesics.

Clinical Management of Chronic Pelvic Pain in Endometriosis Unresponsive to Conventional Therapy

Background: Although several treatments are currently available for chronic pelvic pain, 30–60% of patients do not respond to them. Therefore, these therapeutic options require a better understanding of the mechanisms underlying endometriosis-induced pain. This study focuses on pain management after failure of conventional therapy. Methods: We reviewed clinical data from 46 patients with endometriosis and chronic pelvic pain unresponsive to conventional therapies at Puerta de Hierro University Hospital Madrid, Spain from 2018 to 2021. Demographic data, clinical and exploratory findings, treatment received, and outcomes were collected. Results: Median age was 41.5 years, and median pain intensity was VAS: 7.8/10. Nociceptive pain and neuropathic pain were identified in 98% and 70% of patients, respectively. The most common symptom was abdominal pain (78.2%) followed by pain with sexual intercourse (65.2%), rectal pain (52.1%), and urologic pain (36.9%). A total of 43% of patients responded to treatment with neuromodulators. Combined therapies for myofascial pain syndrome, as well as treatment of visceral pain with inferior or superior hypogastric plexus blocks, proved to be very beneficial. S3 pulsed radiofrequency (PRF) plus inferior hypogastric plexus block or botulinum toxin enabled us to prolong response time by more than 3.5 months. Conclusion: Treatment of the unresponsive patient should be interdisciplinary. Depending on the history and exploratory findings, therapy should preferably be combined with neuromodulators, myofascial pain therapies, and S3 PRF plus inferior hypogastric plexus blockade.

The burden of endometriosis in China from 1990 to 2019

BACKGROUND

The trends in deaths from and disability-adjusted life years (DALY) of endometriosis in China remain largely unknown. This study revealed these trends and the effects of age, period, and cohort on the death from and DALY of endometriosis in China from 1990 to 2019.

METHODS

Data on endometriosis death and DALY in China between 1990 and 2019 were obtained from the Global Burden of Disease Study 2019 (GBD 2019). The annual percentage change and average annual percent change (AAPC) were analyzed by joinpoint regression. The effects of age, period, and birth cohort on death and DALYs were estimated using an age-period-cohort analysis.

RESULTS

The age-standardized death rate (ASDR) and age-standardized DALY rate for endometriosis significantly decreased in China, with AAPC values of -4.7 (95% confidence interval [CI]: -5.10, -4.30) and -1.2 (95% CI: -1.20, -1.10), respectively. The joinpoint regression analysis showed that the ASDR and age-standardized DALY rate decreased across all age groups. Moreover, the effect of age on endometriosis death and DALY decreased with advancing age. Both the period and cohort effects on endometriosis death and DALY showed decreasing trends, with the effects on death decreasing faster than the effects on DALY.

CONCLUSIONS

The endometriosis ASDR and age-standardized DALY rate decreased from 1990 to 2019. The effects of the period and birth cohort on endometriosis death and DALY showed a declining trend across all age groups. The effect of age on endometriosis deaths and DALYs decreased with advancing age.