Effect of human interferon-alpha-2b on experimental endometriosis in rats: comparison between short and long series of treatment

Interferon Signaling in the Endometrium and in Endometriosis

Endometriosis is an estrogen-dependent inflammatory disease that develops in reproductive-aged women who experience pelvic pain and infertility. Even though endometriosis is not a new disease, its molecular etiology has not been clearly elucidated. Defects in the immune system might be one of the factors that promote endometriosis progression. For example, elevated levels of proinflammatory cytokines are associated with endometriosis. Interferon is one of the cytokines that is elevated in endometriotic tissues compared with normal endometrium. Therefore, high interferon levels play a crucial role in endometriosis progression. In addition to endometriosis, however, interferon has a critical role in endometrial function, particularly in the initiation and maintenance of pregnancy. Therefore, this review describes the double-edged sword of interferon signaling in normal endometrial function versus endometriosis progression and also discusses interferon targeting as a new nonhormonal therapy for endometriosis. This approach may increase the efficacy of endometriosis treatment and reduce the adverse effects associated with current hormonal therapy for this disease.

Pentoxifylline for the treatment of endometriosis-associated pain and infertility

BACKGROUND

Endometriosis is a chronic inflammatory condition that occurs during the reproductive years. It is characterised by endometrium-like tissue developing outside the uterine cavity. This endometriotic tissue development is dependent on oestrogen produced primarily by the ovaries and partially by the endometriotic tissue itself, therefore traditional management has focused on ovarian suppression. In this review we considered the role of modulation of the immune system as an alternative approach. This is an update of a Cochrane Review previously published in 2012.

OBJECTIVES

To determine the effectiveness and safety of pentoxifylline in the management of endometriosis.  SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility (CGF) Group Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, and AMED on 16 December 2020, together with reference checking and contact with study authors and experts in the field to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing pentoxifylline with placebo or no treatment, other medical treatment, or surgery in women with endometriosis. The primary outcomes were live birth rate and overall pain (as measured by a visual analogue scale (VAS) of pain, other validated scales, or dichotomous outcomes) per woman randomised. Secondary outcomes included clinical pregnancy rate, miscarriage rate, rate of recurrence, and adverse events resulting from the pentoxifylline intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies against the inclusion criteria, extracted data, and assessed risk of bias, consulting a third review author where required. We contacted study authors as needed. We analysed dichotomous outcomes using Mantel-Haenszel risk ratios (RRs), 95% confidence intervals (CIs), and a fixed-effect model. For small numbers of events, we used a Peto odds ratio (OR) with 95% CI instead. We analysed continuous outcomes using the mean difference (MD) between groups presented with 95% CIs. We used the I2 statistic to evaluate heterogeneity amongst studies. We employed the GRADE approach to assess the quality of the evidence.

MAIN RESULTS

We included five parallel-design RCTs involving a total of 415 women. We included one additional RCT in this update. Three studies did not specify details relating to allocation concealment, and two studies were not blinded. There were also considerable loss to follow-up, with four studies not conducting intention-to-treat analysis. We judged the quality of the evidence as very low. Pentoxifylline versus placebo No trials reported on our primary outcomes of live birth rate and overall pain. We are uncertain as to whether pentoxifylline treatment affects clinical pregnancy rate when compared to placebo (RR 1.38, 95% CI 0.91 to 2.10; 3 RCTs, n = 285; I2 = 0%; very low-quality evidence). The evidence suggests that if the clinical pregnancy rate with placebo is estimated to be 20%, then the rate with pentoxifylline is estimated as between 18% and 43%. We are also uncertain as to whether pentoxifylline affects the recurrence rate of endometriosis (RR 0.84, 95% CI 0.30 to 2.36; 1 RCT, n = 121; very low-quality evidence) or miscarriage rate (Peto OR 1.99, 95% CI 0.20 to 19.37; 2 RCTs, n = 164; I2 = 0%; very low-quality evidence). No trials reported on the effect of pentoxifylline on improvement of endometriosis-related symptoms other than pain or adverse events. Pentoxifylline versus no treatment No trials reported on live birth rate. We are uncertain as to whether pentoxifylline treatment affects overall pain when compared to no treatment at one month (MD -0.36, 95% CI -2.12 to 1.40; 1 RCT, n = 34; very low-quality evidence), two months (MD -1.25, 95% CI  -2.67 to 0.17; 1 RCT, n = 34; very low-quality evidence), or three months (MD -1.60, 95% CI -3.32 to 0.12; 1 RCT, n = 34; very low-quality evidence). No trials reported on adverse events caused by pentoxifylline or any of our other secondary outcomes. Pentoxifylline versus other medical therapies One study (n = 83) compared pentoxifylline to the combined oral contraceptive pill after laparoscopic surgery to treat endometriosis, but could not be included in the meta-analysis as it was unclear if the data were presented as +/- standard deviation and what the duration of treatment was. No trials reported on adverse events caused by pentoxifylline or any of our other secondary outcomes. Pentoxifylline versus conservative surgical treatment  No study reported on this comparison.

AUTHORS' CONCLUSIONS

No studies reported on our primary outcome of live birth rate. Due to the very limited evidence, we are uncertain of the effects of pentoxifylline on clinical pregnancy rate, miscarriage rate, or overall pain. There is currently insufficient evidence to support the use of pentoxifylline in the management of women with endometriosis with respect to subfertility and pain relief outcomes.

Medical management of endometriosis

INTRODUCTION

Endometriosis is a benign gynecologic disorder that is defined as functional endometrial tissue outside of the uterine cavity. It is an estrogen-dependent, inflammatory disease that leads to symptoms of pelvic pain, dysmenorrhea, dyspareunia, and infertility, occurring in 6-10% of reproductive aged women. The severity of the disease ranges from asymptomatic to debilitating symptoms that have a major impact on women's lives. It is a chronic, recurrent disease, frequently requiring long term management until menopause and beyond. It is considered a chronic disorder that is managed with surgery, medical treatment, and oftentimes, both. Current medical therapy for endometriosis is considered suppressive of the disease, rather than curative. Fortunately, many patients do experience improvement and control of their symptoms with medical therapy. However, long-term efficacy of the medical treatments is often limited by side effects and the cost of therapy, and symptoms do tend to recur after discontinuation of these medications.

AREAS COVERED

This review summarizes our understanding of the pathogenesis of endometriosis and provides more in-depth discussion of specific medical management options used to treat endometriosis, including mechanism of action and side effects. It also provides recommendations on strategy with a forward look to novel endometriosis treatments in the future.

EXPERT OPINION

The authors emphasize that endometriosis is a chronic disorder requiring long term medical therapy. Early diagnosis of endometriosis is key in preventing severe, debilitating symptoms and progression of disease. By utilizing our current knowledge of the pathophysiology of endometriosis and by correctly implementing currently available medical and surgical therapies we can significantly reduce the physical, psychosocial and financial burden of this chronic, recurrent and indolent disease. Current available medications are suppressive therapies, but the authors are looking forward to future therapies that can effectively cure or at least control endometriosis with minimal side effects. Future research should continue to look for the genetic trigger for endometriosis which can lead us to its underlying pathogenesis and eventually a cure or prevention.

Role of inflammation in benign gynecologic disorders: from pathogenesis to novel therapies†

Emerging evidence supports the notion that inflammation fosters the development of common benign gynecologic disorders, including uterine leiomyoma, endometriosis, and adenomyosis. Numerous cytokines, chemokines, and growth and transcription factors have indisputable roles in the establishment and maintenance of benign gynecologic disorders by initiating complex cascades that promote proliferation, angiogenesis, and lesion progression. The interaction between inflammation and benign gynecologic disorders is orchestrated by a plethora of factors, including sex steroids, genetics, epigenetics, extracellular matrix, stem cells, cardiometabolic risk factors, diet, vitamin D, and the immune system. The role of inflammation in these disorders is not limited to local pathobiology but also extends to involve clinical sequelae that range from those confined to the reproductive tract, such as infertility and gynecologic malignancies, to systemic complications such as cardiovascular disease. Enhanced understanding of the intricate mechanisms of this association will introduce us to unvisited pathophysiological perspectives and guide future diagnostic and therapeutic implications aimed at reducing the burden of these disorders. Utilization of inflammatory markers, microRNA, and molecular imaging as diagnostic adjuncts may be valuable, noninvasive techniques for prompt detection of benign gynecologic disorders. Further, use of novel as well as previously established therapeutics, such as immunomodulators, hormonal treatments, cardiometabolic medications, and cyclooxygenase-2 and NF-κB inhibitors, can target inflammatory pathways involved in their pathogenesis. In this comprehensive review, we aim to dissect the existing literature on the role of inflammation in benign gynecologic disorders, including the proposed underlying mechanisms and complex interactions, its contribution to clinical sequelae, and the clinical implications this role entails.

Peritoneal fluid biomarkers in patients with endometriosis: a cross-sectional study

OBJECTIVES

Elevated concentrations of numerous molecules have been reported in the peritoneal cavity of women with endometriosis. Until now, no factor proved sufficiently specific to endometriosis. We aimed to investigate several biomarkers in endometriosis and report their association with the menstrual cycle in a large sample size study.

METHODS

Patients of reproductive age undergoing laparoscopic procedures for benign pathology in the Department of Obstetrics and Gynaecology, University of Bern between 2007 and 2018 were included. Exclusion criteria were the use of hormonal treatment in the three months prior to surgery, patients suffering from other inflammatory diseases, pregnancy, malignancy and surgery performed in an emergency. The concentrations of 13 different biomarkers in the peritoneal fluid (PF) were compared between patients with and without endometriosis both in the proliferative and the secretory cycle phase.

RESULTS

Out of 1,256 patients in the database, 521 met the inclusion and exclusion criteria. Glycodelin (PP14) and Midkine concentrations were significantly higher in patients with endometriosis compared to controls irrespective of the cycle phase in which the PF was collected. Interleukin-8 (IL-8), regulated on activation normal T cell expressed and secreted (RANTES) and osteoprotegerin (OPG) concentrations were higher in patients with endometriosis only in the proliferative cycle phase. Monocyte chemoattractant protein 1, CCL2 (MCP-1) and Defensin concentrations were higher in patients with endometriosis only in the secretory cycle phase.

CONCLUSIONS

Certain pathophysiological processes may take place only in the one cycle phase leading to a temporary increase of specific PF biomarkers. Correlation with clinical outcomes is mandatory to establish their potential as prognostic or therapeutic tools in endometriosis.

Transcriptome meta-analysis reveals differences of immune profile between eutopic endometrium from stage I-II and III-IV endometriosis independently of hormonal milieu

Eutopic endometrium appears to be crucial for endometriosis development. Despite of the evident importance, data regarding the cellular microenvironment remain unclear. Our objective was to explore the tissue microenvironment heterogeneity, transcripts, and pathways that are enriched in all phases of the menstrual cycle by analysing publicly deposited data derived from whole transcriptome microarrays of eutopic endometria of women with and without endometriosis. A meta-analysis of the transcriptome microarrays was performed using raw data available from a public database. Eligibility criteria included eutopic endometrium samples from women with endometriosis and healthy controls without any pathological condition reported the presence of an adequately reported normal menstrual phase, and samples containing both glandular and stromal components. Raw data were processed using a robust multiarray average method to provide background correction, normalisation, and summarisation. The batch effect was estimated by principal variant component analysis and removed using an empirical Bayes method. Cellular tissue heterogeneity was inferred using the xCell package. Differentially expressed genes were identified based on a 5% adjusted p value and a 2.0-fold change. Pathways were identified by functional enrichment based on the Molecular Signatures Database, a p value of < 5%, and an FDR q value of ≤ 25%. Genes that were more frequently found in pathways were identified using leading edge analysis. In a manner independent of cycle phase, the subpopulations of activated dendritic cells, CD4 T effector memory phenotype cells, eosinophils, macrophages M1, and natural killer T cells (NKT) were all higher in stage I-II endometriosis compared to those in healthy controls. The subpopulations of M2 macrophages and natural killer T cells were elevated in eutopic endometriums from women with stage III-IV endometriosis, and smooth muscle cells were always more prevalent in healthy eutopic endometriums. Among the differently expressed genes, FOS, FOSB, JUNB, and EGR1 were the most frequently mapped within the interaction networks, and this was independent of stage and cycle phase. The enriched pathways were directly related to immune surveillance, stem cell self-renewal, and epithelial mesenchymal transition. PI3K AKT mTOR, TGF signalling, and interferon alpha/gamma responses were enriched exclusively in stage III-IV endometriosis. The cellular microenvironments and immune cell profiles were different between eutopic endometriums from women with stage I-II and stage III-IV endometriosis, and these differences were independent of the hormonal milieu. Specifically, a pro-inflammatory profile was predominant in stage I-II endometriosis, and M1-M2 polarization into eutopic endometrium may be crucial for the progression of the disease. The higher prevalence of NKT cells in eutopic endometriums from women with endometriosis that was independent of cycle phase or staging suggested a sustained stress and/or damage to these eutopic endometriums. Based on this, the results of this meta-analysis are important for identifying challenges and opportunities for future research.

Effects of human recombinant type I IFNs (IFN-α2b and IFN-β1a) on growth and migration of primary endometrial stromal cells from women with deeply infiltrating endometriosis: A preliminary study

OBJECTIVE(S)

Endometriosis is a major cause of infertility and disability for women, caused by the presence of inflammatory endometrial implants in extrauterine locations. Among the constituents involved in the immune response during the development of endometriosis, several chemokines, including interferons (IFNs) may have a role in the pathogenesis of this disease. The aim of this preliminary study was to investigate the anti-proliferative and anti-migratory activities of type I IFNs (IFN-α2b and IFN-β1a) in primary endometrial stromal cells (ESCs) isolated from women with deeply infiltrating endometriosis (DIE).

STUDY DESIGN

The study subjects included 7 women ranged in the age from 27 to 37 years with diagnosis of DIE (Stage III and IV). Collected primary ESC monolayers, isolated from endometriotic nodules, were incubated with various concentrations (from 1 to 1000 IU/ml) of IFN-α2b or IFN-β1a.

RESULT(S)

IFN-β1a had a significantly higher activity in hampering the proliferation of cells compared to IFN-α2b. This effect could be related to the induction of apoptosis and cell cycle arrest in S phase, observed in ESCs during incubation with IFN-β1a. Moreover, IFN-β1a was more potent than IFN-α2b in inhibiting migration and EGF-induced ERK activity of primary ESCs.

CONCLUSION(S)

The inhibitory in vitro effect on ESC proliferation and migration of IFN-β1a was much more potent than IFN-α2b. These preliminary data offer the rationale for future preclinical and clinical trials using IFN-β1a as a new tool for the therapy and tertiary prevention in patients with DIE.

Effects of cisplatin on surgically induced endometriosis in a rat model

Research has strongly suggested that the features of endometriosis serve as a precursor lesion of ovarian cancer. Cisplatin (CDDP) is the preferred drug against these cancer types. The present study investigated the effects of CDDP on surgically induced endometriosis in a rat model. Endometriosis was surgically induced by the autologous transplantation of endometrial tissue. A total of 36 model rats were randomly divided into three groups. The rats in Group 1 (control group, n=12) received no medication. The rats in Group 2 (n=12) and Group 3 (n=12) were administered 35 mg/m² CDDP and 70 mg/m² CDDP, respectively, every four days. All rats were treated for a total of 24 days. The growth and histologic scores of the implants were calculated. The expression of protein markers, including vascular endothelial growth factor (VEGF), aromatase P450 (P450arom), transforming growth factor-β (TGF-β) and matrix metalloproteinase (MMP)-2, were assessed using immunohistochemistry, an enzyme-linked immunosorbent assay and western blot analysis. Following CDDP treatment, the mean implant sizes were significantly reduced in Groups 2 and 3 compared with the control group (P=0.01). The mean histologic scores were also significantly lower in Groups 2 and 3. Furthermore, the protein expression of VEGF, P450arom, TGF-β and MMP-2 was significantly lower in Groups 2 and 3 when compared with the control group. A loss of hair was observed in 4 rats, which only occurred in Group 3. A dose-dependent effect was observed in the two CDDP-treated groups. In conclusion, the expression of proliferation- and angiogenesis-associated proteins was significantly lower following treatment with CDDP. CDDP caused a significant regression in the size of the endometriotic implants and induced atrophy of these lesions in rats.

New developments in the medical treatment of endometriosis

Endometriosis affects 1 in 10 women of reproductive-age. The current treatments are surgical and hormonal but have limitations, including the risk of recurrence, side effects, contraceptive action for women who desire pregnancy, and cost. New treatments include gonadotropin-releasing hormone analogues, selective progesterone (or estrogen) receptor modulators, aromatase inhibitors, immunomodulators, and antiangiogenic agents. Further research is needed into central sensitization, local neurogenesis, and the genetics of endometriosis to identify additional treatment targets. A wider range of medical options allows for the possibility of precision health and a more personalized treatment approach for women with endometriosis.

Novel agents for the medical treatment of endometriosis

PURPOSE OF REVIEW

Current medical treatments for endometriosis-associated pain, including oral contraceptives, progestins and GnRH agonists, are partially effective and have significant side-effects. The purpose of this review is to present new hormonal and nonhormonal treatment for endometriosis.

RECENT FINDINGS

At present, the ideal drug that can prevent, inhibit or stop development of endometriosis, reduce associated pain or infertility and allow conception does not exist. New drugs in development for endometriosis modulate GnRH, estrogen and/or progesterone receptors, or target endometriosis-associated inflammation, angiogenesis, adhesion and/or tissue invasion. Most have been tested in rodents, and have been evaluated in more relevant animal models like nonhuman primates (baboons), but only a few, that is GnRH antagonists, have been tested in human randomized controlled trials. Important safety and efficacy issues remain a concern, as steroid receptors, inflammation, adhesion, angiogenesis and tissue invasion are key factors in physiological events like ovulation, menstruation and embryo implantation.

SUMMARY

New drugs for the medical treatment of endometriosis targeting both hormonal (GnRH, estrogen and progesterone receptors) and nonhormonal pathways (inflammation, angiogenesis, adhesions, tissue invasion) are promising, but their efficacy and safety need to be established in randomized human trials before they can be used in clinical practice.