Effect of ovarian involvement on peritoneal fluid cytokine concentrations in endometriosis patients

Peritoneal fluid cytokines are important for initiation and progression of endometriosis. The objective of this study was to compare a group of five cytokines (interleukins IL-1β, IL-6, IL-8, IL-13 and tumour necrosis factor α; TNFα) in peritoneal fluid of endometriosis patients with ovarian involvement (Group I, n = 17) to those in patients without ovarian involvement (Group II, n = 33) and to a reference group without endometriosis (Group III, n = 25). All three groups were comparable regarding age, parity and body mass index. IL-8 concentrations were significantly higher in groups I and II compared with the reference group (P = 0.01 and 0.02, respectively). Similarly, TNFα concentrations were significantly higher in groups I and II compared with the reference group (P < 0.0001 and 0.0004, respectively). All other cytokines were comparable in the three groups. No significant differences were found between groups I and II with respect to the cytokines measured. In conclusion, peritoneal fluid IL-8 and TNFα concentrations are significantly higher in endometriosis. Ovarian involvement does not alter the pattern of cytokines. It appears that the inflammatory mediators of endometriosis are similar with and without ovarian involvement.