Circulating and peritoneal fluid interleukin-6 levels and gene expression in pelvic endometriosis

Abstract

Abstract. Current data are inconsistent regarding the association between interleukin-6 (IL-6), a marker of acute phase inflammation, and pelvic endometriosis. The aim of the present study was to assess IL-6 levels in serum and peritoneal fluid (PF), as well as IL-6 gene expression in adipose tissue (AT) and endometrial samples in pelvic endometriosis. A total of 30 patients with endometriosis and 18 women with a normal pelvis were enrolled in this case-control study. IL-6 levels in PF and serum were determined using a human enzyme-linked immunosorbent assay and IL-6 gene expression was evaluated using reverse transcription-quantitative polymerase chain reaction. It was observed that IL-6 levels in the PF were higher in patients with endometriosis than in the control group (P=0.047) and patients with stage III/IV endometriosis exhibited higher IL-6 levels in the PF than those with stage I/II endometriosis and the control group (P<0.001). Furthermore, a strong correlation between PF IL-6 levels and the revised American Society for Reproductive Medicine score for endometriosis severity was identified (r=0.77; P<0.001). IL-6 gene expression did not differ significantly between endometriosis and control groups in endometrial samples or in AT of both groups. The results of the current study suggest that there may be an association between IL-6 and the presence and severity of pelvic endometriosis. The source of this higher IL-6 seems not to be specifically related to regional AT.

Inflammatory Mediators and Pain in Endometriosis: A Systematic Review

“…These high concentrations of TGF-β in the peritoneal fluid may create suitable conditions for the ectopic lesion formation. In a similar study of reference [ 39 ], the expression rate of IL-6 was also higher in patients with endometriosis and it had a dependence on the stage of the disease (higher in III/IV vs. I/II stage). Additionally, steroid hormone fluctuations occurring during the menstrual cycle seem not to affect the IL-6 synthesis.…”

Resveratrol treatment reduces expression of MCP‐1, IL‐6, IL‐8 and RANTES in endometriotic stromal cells

“…However, retrograde menstruation occurs in almost all reproductive‐aged women, but only 10%‐20% of them develop endometriosis, so other factors must be involved in implantation and survival of the displaced endometrial cells 5 . Based on recent findings, immune dysregulation in the peritoneal microenvironment and chronic inflammation have crucial roles in endometriosis development 6 as increased levels of pro‐inflammatory cytokines and chemokines such as interleukin‐6 (IL‐6), IL‐8, monocyte chemotactic protein‐1 (MCP‐1), and regulated upon activation, normal T cell expressed and secreted (RANTES) have been detected in peritoneal fluid (PF) of endometriotic patients compared to non‐endometriotic participants, suggesting that these secretory products may be involved in endometriosis initiation and progression through the promotion of growth, adhesion, invasion and proliferation of endometrial cells 7‐9 …”

“…in the peritoneal microenvironment and chronic inflammation have crucial roles in endometriosis development 6 as increased levels of pro-inflammatory cytokines and chemokines such as interleukin-6 (IL-6), IL-8, monocyte chemotactic protein-1 (MCP-1), and regulated upon activation, normal T cell expressed and secreted (RANTES) have been detected in peritoneal fluid (PF) of endometriotic patients compared to non-endometriotic participants, suggesting that these secretory products may be involved in endometriosis initiation and progression through the promotion of growth, adhesion, invasion and proliferation of endometrial cells. [7][8][9] Current treatment modalities for endometriosis are surgical and hormonal treatments, but the high incidence of disease recurrence and side effects of these therapies limit their usage in a long period. 10 Thus, in recent years, there has been an increasing emphasis on finding naturally occurring compounds for the management of endometriosis.…”

Diagnostic Value of Endometrial Nerve Endometrial Tissue of Patients with Endometriosis

“…De Andrade et al [14] reported that an increase in interleukin 6 (IL-6) expression was associated with the severity of endometriosis. Elgafor El Sharkwy et al [15] examined endometrial samples from 74 endometriosis patients for PGP 9.5 and blood samples from 40 control group participants for IL-6.…”

“…[8][9][10][11][12][13][14][15][16] Progesterone treatment revealed a decrease in endometrial nerve fibers, but no clinical significance was identified. [17] As a result, further studies were recommended in recent publications for these patient groups.…”