CD4(+) CD25(high) Foxp3(+) cells increased in the peritoneal fluid of patients with endometriosis

PROBLEM: To evaluate CD4(+) CD25(high) Foxp3(+) cells and IL-6, IL-10, IL-17, and TGF-β in the peritoneal fluid of women with endometriosis. METHOD OF STUDY: A total of ninety-eight patients were studied: endometriosis (n = 70) and control (n = 28). First, peritoneal fluid lymphocytes were isolated, and CD4(+) CD25(high) cells were identified using flow cytometry. Then, RT-PCR was performed to verify Foxp3 expression in these cells. Also, IL-6, IL-10, IL-17, and TGF-β concentration was determined. RESULTS: Of all the lymphocytes in the peritoneal fluid of women with endometriosis, 36.5% (median) were CD4(+) CD25(high) compared to only 1.15% (median) in the control group (P < 0.001). Foxp3 expression was similarly elevated in patients with the disease compared to those without (median, 50 versus 5; P < 0.001). IL-6 and TGF-β were higher in endometriosis group (IL-6: 327.5 pg/mL versus 195.5 pg/mL; TGF-β: 340 pg/mL versus 171.5 pg/mL; both P < 0.001). IL-10 and IL-17 showed no significant differences between the two groups. CONCLUSION: The peritoneal fluid of patients with endometriosis had a higher percentage of CD4(+) CD25(high) Foxp3(+) cells and also higher levels of IL-6 and TGF-β compared to women without the disease. These findings suggest that CD4(+) CD25(high) Foxp3(+) cells may play a role in the pathogenesis of endometriosis.