Decreased peritoneal concentrations of interleukin-15 in women with advanced stage endometriosis

OBJECTIVE: To assess the concentrations of interleukin-15 (IL-15) in peritoneal fluid from women with endometriosis and fertile disease-free controls. STUDY DESIGN: Peritoneal fluid samples were obtained from 50 women with endometriosis and 29 fertile women having tubal ligation. Concentrations of IL-15 were measured. RESULTS: The mean (S.D.s) concentration of IL-15 in peritoneal fluid was 11.17 pg/mL (3.89) for women with endometriosis, and 12.59 pg/mL (4.11) for fertile disease-free controls. The difference of peritoneal IL-15 concentrations between endometriosis and control women was not statistically significant. However, peritoneal IL-15 concentrations were significantly lower in women with moderate/severe endometriosis when compared with those in women with minimal/mild endometriosis, and in controls (P<0.05). In addition, peritoneal IL-15 concentrations did not correlate with the phase of menstrual cycle in endometriosis or control women. CONCLUSIONS: Our results suggest that the decreased peritoneal IL-15 concentrations in women with moderate/severe endometriosis imply a role of IL-15 in the pathogenesis of advanced endometriosis as compared to those with minimal/mild endometriosis and fertile disease-free controls.