Clinical immunology
The estimation of IL-2 and IL-2 receptors in peritoneal fluid of infertile patients with endometriosis

Background: The aim of the study was to investigate the concentrations of interleukin-2 (IL-2), soluble interleukin-2 receptors (sIL-2R) and the expressions of CD25 antigen (IL-2Rα) on T CD3+ lymphocytes in peritoneal fluid of infertile patients with endometrisis in comparison with the reference group of patients with benign ovarian tumors. Material and Methods: Twenty four infertile patients with endometriosis and 18 patients from reference group were included in the study. The concentrations of IL-2 and soluble IL-2 receptors were measured with the use of ELISA immunoenzymatic method. The expressions of surface molecules were estimated using the two-color flow cytometric method. Results: The concentrations of IL-2 in peritoneal fluid of infertile patients with endometriosis were significantly higher when compared to the reference group (2.83±2.6 pg/ml vs. 1.27±1.58 pg/ml; p<0.05). The concentrations of soluble IL-2 receptors and the expressions of CD25 antigen on T CD3+ lymphocytes in the study group did not differ significantly when compared to the reference group (sIL-2R: 463.9±200.4 U/ml vs. 461.35±209.7 U/ml; NS; T CD3+CD25+: 6.77±8.18% vs. 5.7±6.43%; NS). However, we have found significant differences in immunological parameters between individual stages of endometriosis. The expressions of CD25 antigen were significantly higher in the second and third stages of endometriosis when compared to the first stage of the disease. Conclusions: The excessive concentrations of IL-2 in peritoneal fluid of patients with endometriosis may be responsible for an infertilty in these group of patients. Higher expressions of CD25 antigen on T CD3+ lymphocytes which are observed in the third and second stage of endometriosis can suggest the acivation of T CD3+ cells during the progression of the disease.