Soluble Factors CD14, CD163, and Migration Inhibitory Factor Are Associated with Endometriosis-Related Infertility.

OBJECTIVES: Myeloid cell-derived factors contribute to the immunopathology of endometriosis. Soluble CD14 (sCD14), CD163 (sCD163), and MIF serve as in vivo markers of myeloid function. However, these soluble molecules are largely unexplored in women with endometriosis-related infertility cases. We investigated three soluble markers, namely sCD14, sCD163, and MIF, in cases of infertility associated with endometriosis and correlated its level to the stage of endometriosis. DESIGN: Eighty-seven women newly diagnosed with endometriosis or other benign gynecologic control cases linked to infertility were prospectively recruited and underwent diagnostic laparoscopy. PARTICIPANTS: Forty-four patients with endometriosis were included in this study, comprising 19 patients with early-endometriosis (stages I and II) and 25 late-endometriosis (stages III and IV) based on the revised American Society for Reproductive Medicine (rASRM) classification. The remaining 43 patients constituted a control group with infertility due to other causes. METHODS: The levels of sCD14, sCD163, and MIF in serum and peritoneal fluid were assessed using ELISA. RESULTS: Endometriosis women exhibited significantly higher serum levels of sCD163 and MIF levels compared to the control group. Both sCD163 and MIF levels displayed a positive correlation with the rASRM adhesion score. Moreover, the MIF level in serum had a positive correlation with the rASRM endometriosis score. In receiver operating characteristic analysis, serum sCD163 and MIF could significantly discriminate endometriosis and non-endometriosis in infertility cases. LIMITATIONS: Some limitations of the current study deserve to be underlined. First, the sensitive ELISA method was the sole-validated tool for detecting the markers in patient samples. Second, healthy or fertile women were not involved as the control group. CONCLUSIONS: The elevated systemic levels of sCD163 and MIF correlated with the severity of endometriosis. These soluble molecules have a potential diagnostic capacity as a non-invasive biomarker. Furthermore, our data warrants future studies on the underlying mechanism of sCD163 and MIF in endometriosis-related infertility.

IL-8 and IL-12p70 are associated with pelvic pain among infertile women with endometriosis.

OBJECTIVE: To evaluate interleukin (IL)-1ß, IL-6, IL-8, and IL-12p70 levels in serum and peritoneal fluid in women related to infertility and pelvic pain. METHODS: Eighty-seven women were diagnosed with endometriosis or cases related to infertility. IL-1ß, IL-6, IL-8, and IL-12p70 levels in serum and peritoneal fluid were determined by enzyme-linked immunosorbent assay (ELISA). Pain assessment was evaluated by the Visual Analog Scale (VAS) score. RESULTS: Serum IL-6 and IL-12p70 levels increased in women with endometriosis compared to the control group. Serum and peritoneal IL-8 and IL-12p70 levels correlated with VAS scores in infertile women. A positive correlation was also found between peritoneal IL-1ß and IL-6 with VAS score. A significant difference in peritoneal IL-1ß levels was associated with menstrual pelvic pain, while peritoneal IL-8 levels were related to dyspareunia, menstrual, and post-menstrual pelvic pain in infertile women. CONCLUSIONS: An association of IL-8 and IL-12p70 levels were related to pain in endometriosis, as well as a relationship between cytokine expression and VAS score. Further studies should be addressed to investigate the precise mechanism of cytokine-related pain in endometriosis.

Elevated peritoneal soluble endoglin and GDF-15 in infertile women with severe endometriosis and pelvic adhesion.

OBJECTIVES: Chronic inflammation and pelvic adhesion play a critical role in endometriosis-related infertility. Research studies suggest that TGF-ß superfamily members, such as soluble endoglin (sEng), growth differentiation factor 15 (GDF-15) and tumor growth factor-beta (TGF-ß1) contribute to the regulation of inflammation, angiogenesis and cell adhesion. The objective of this study is to investigate the association between the concentrations of these TGF-ß-related members and the clinical parameters of infertile women with endometriosis. MATERIALS AND METHODS: Sixty-five infertile women who underwent laparoscopy were divided into two groups in this study: those who had endometriosis (n = 33) and control subjects with benign gynecologic disorders (n = 32). The levels of TGF-ß- related members in peritoneal fluid and serum were evaluated by the enzyme-linked immunosorbent assay (ELISA). Clinical and hematological parameters were documented and analyzed. RESULTS: Endometriosis cases had significantly higher levels of sEng, GDF-15 and TGF-ß1 in peritoneal fluid (p<0.0005) compared to control subjects, but not in serum. Moreover, serum GDF-15 level was significantly elevated in the late-stage endometriosis compared to the early-stage group. The levels of three TGF-ß related molecules in peritoneal fluid showed positive correlations with rASRM score. Blood neutrophil counts have correlation with the peritoneal sEng concentration. CONCLUSION: Our novel evidence on the elevated concentration of peritoneal sEng and GDF-15 in endometriosis, specifically in the late-stage, may indicate the essential role of TGF-ß-dependent signaling in endometriosis. Serum GDF-15 might serve as a candidate biomarker for endometriosis severity. Further studies are warranted to investigate the role and regulation of these molecules in endometriosis.

Soluble immune checkpoints CTLA-4, HLA-G, PD-1, and PD-L1 are associated with endometriosis-related infertility.

PROBLEM: Soluble immune checkpoint molecules constitute the emerging novel mediators in immune regulation. Their role in the pathogenesis of endometriosis has not been fully addressed. In this study, we aimed to investigate the relationship between the clinical manifestation of endometriosis-associated infertility and the level of four soluble immune checkpoints: sCTLA4, sHLA-G, sPD-1, and sPD-L1. METHOD OF STUDY: The soluble immune checkpoint concentrations in serum and peritoneal fluid from 88 patients who underwent laparoscopy were evaluated by the enzyme-linked immunosorbent assay (ELISA). Clinical and hematological parameters were documented and analyzed. RESULTS: Endometriosis cases were evident to have significantly higher levels of serum sPD-L1 and all four molecules in peritoneal fluid compared to non-endometriosis control. Contrary, no significant differences were found in the concentration of serum sCTLA-4, sHLA-G and, sPD-1 between endometriosis and control group. There were significant positive correlations between serum and peritoneal fluid concentrations of sCTLA-4, sPD-L1, and sHLA-G. Serum sPD-L1 could discriminate endometriosis-related infertility to other pathological control. At a cutoff of 14,61 pg/mL, serum sPD-L1 had a sensitivity of 77% and specificity of 83%. Moreover, sPD-L1 level showed positive correlations with pelvic adhesion score and myeloid cell count. CONCLUSION: The elevated level of sPD-L1 in serum and immune checkpoint molecules in the peritoneal fluid could represent the hallmark of immune regulation in endometriosis. Serum sPD-L1 could serve as a potential noninvasive endometriosis biomarker. Also, the immune compartment related to the local immune checkpoint molecules may be implicated in biological mechanisms underlying endometriosis-related infertility.