Peritoneal fluid concentrations of ciliary neurotrophic factor, a gp130 cytokine, in women with endometriosis

The dysregulation of leukemia inhibitory factor and its implications for endometriosis pathophysiology

Endometriosis is an estrogen dominant, chronic inflammatory disease characterized by the growth of endometrial-like tissue outside of the uterus. The most common symptoms experienced by patients include manifestations of chronic pelvic pain- such as pain with urination, menstruation, or defecation, and infertility. Alterations to Leukemia Inhibitory Factor (LIF), a cytokine produced by the luminal and glandular epithelium of the endometrium that is imperative for successful pregnancy, have been postulated to contribute to infertility. Conditions such as recurrent implantation failure, unexplained infertility, and infertility associated diseases such as adenomyosis and endometriosis, have demonstrated reduced LIF production in the endometrium of infertile patients compared to fertile counterparts. While this highlights the potential involvement of LIF in infertility, LIF is a multifaceted cytokine which plays additional roles in the maintenance of cell stemness and immunomodulation. Thus, we sought to explore the implications of LIF production within ectopic lesions on endometriosis pathophysiology. Through immunohistochemistry of an endometrioma tissue microarray and ELISA of tissue protein extract and peritoneal fluid samples, we identify LIF protein expression in the ectopic lesion microenvironment. Targeted RT qPCR for LIF and associated signaling transcripts, identify LIF to be significantly downregulated in the ectopic tissue compared to eutopic and control while its receptor, LIFR, is upregulated, highlighting a discordance in ectopic protein and mRNA LIF expression. In vitro treatment of endometriosis representative cell lines (12Z and hESC) with LIF increased production of immune-recruiting cytokines (MCP-1, MCP-3) and the angiogenic factor, VEGF, as well as stimulated tube formation in human umbilical vein endothelial cells (HUVECs). Finally, LIF treatment in a syngeneic mouse model of endometriosis induced both local and peripheral alterations to immune cell phenotypes, ultimately reducing immunoregulatory CD206+ small peritoneal macrophages and T regulatory cells. These findings suggest that LIF is present in the ectopic lesions of endometriosis patients and could be contributing to lesion vascularization and immunomodulation.

Using Symptom Scores, Lifestyle Measures and Biochemical Markers to Create a Test for Endometriosis

Purpose

The purpose of this study was to develop a test to discriminate between women suffering from pelvic pain associated with presence or absence of endometriosis, using symptom visual analogue scale (VAS) scores, demographic and lifestyle factors and known and novel plasma biomarkers.

Methods

This was a prospective cohort study. We recruited women presenting with pelvic pain symptoms and undergoing laparoscopy. They provided a plasma sample and completed a questionnaire assessing symptom VAS scores, lifestyle factors and demographic details. Plasma was assayed for 18 potential biomarkers. Logistic regression was used to develop a test to discriminate between women with pelvic pain associated with presence or absence of endometriosis.

Results

A series of 101 women were analyzed. On univariate analysis, women with endometriosis were less likely to be parous or have previously used an intrauterine contraceptive device (IUD) but have a higher weekly alcohol intake. These women had higher VAS scores for nausea and dyspareunia, and higher plasma levels of cancer antigen 125 (CA-125). The optimum logistic regression model included parity, previous IUD use, history of endometriosis, weekly alcohol intake, dyspareunia, VAS score and CA-125. This model had a sensitivity of 93%, specificity of 62% and accuracy of 83%.

Conclusions

Combining symptom scores, historical measures and CA-125 provides a reasonable means to discriminate between women with pelvic pain associated with presence or absence of endometriosis, but greater specificity is needed before such a model could replace laparoscopy.

Endometriosis: the role of neuroangiogenesis

Endometriosis is a common cause of pelvic pain and infertility, affecting ∼10% of reproductive-age women. Annual costs for medical and surgical care in the United States exceed $20 billion. The disorder is characterized by implants of endometrial tissue outside the uterine cavity. Endometriotic lesions induce a state of chronic peritoneal inflammation, accompanied by elevated prostaglandin, cytokine, and growth factor concentrations. The current therapy is surgical ablation of ectopic implants and hormones that block the hypothalamic-pituitary-ovarian axis, but these approaches are expensive, carry perioperative risks, or have unpleasant side effects of hypoestrogenism. Recent evidence indicates that ectopic endometriotic implants recruit their own unique neural and vascular supplies through neuroangiogenesis. It is believed that these nascent nerve fibers in endometriosis implants influence dorsal root neurons within the central nervous system, increasing pain perception in patients. We consider the mechanisms and therapeutic implications of neuroangiogenesis in these lesions and propose potential treatments for the control or elimination of endometriosis-associated pain.