Serum and peritoneal fluid levels of interleukin-6 and interleukin-37 as biomarkers for endometriosis

This study aimed to compare the levels of interleukin (IL)-1β, IL-6, IL-10, and IL-37 in the serum and peritoneal fluid of women with and without endometriosis. In addition, it aimed to determine the diagnostic values of the cytokines with significantly different concentrations. The levels of IL-1β, IL-6, IL-10, and IL-37 in the serum and peritoneal fluid samples of 40 women with endometriosis and 32 women without endometriosis were measured using an enzyme-linked immunosorbent assay. The serum and peritoneal fluid levels of IL-1β and IL-10 were not statistically significantly different between the endometriosis and control groups. The IL-6 and IL-37 levels in the serum and peritoneal fluid were higher in the endometriosis group than in the control group, and they were correlated with the stage of endometriosis. The AUC for the IL-37 was 0.897 for the serum and 0.934 for the peritoneal fluid, while the AUC for the IL-6 was 0.905 for the serum and 0.952 for the peritoneal fluid. Our results suggest that the serum and peritoneal fluid IL-6 and IL-37 levels were significantly increased in the endometriosis patients, indicating that these cytokines may serve as biomarkers for the diagnosis of endometriosis.