Increased percentage of Th17 cells in peritoneal fluid is associated with severity of endometriosis

Aim Th17 cells are a newly discovered T helper lymphocyte subpopulation, producing interleukin IL-17. Th17 cells are present in blood and peritoneal fluid (PF) at different stages of endometriosis. We aim to establish their potential importance in the pathogenesis and clinical features of the disease. Methods The percentage of Th17 cells among T helper lymphocytes was determined in the PF and peripheral blood (PB) of patients with endometriosis and in the control group by flow cytometry using monoclonal antibodies: anti-CD-4-FITC, anti-CD-3-PE/Cy5, and anti-IL-17A-PE. Results Th17 percentage is increased in PF in comparison with PB in both endometriotic patients and in the control group. In severe endometriosis, the percentage of Th17 cells in PF was higher than with early (I/II stage) endometriosis. A positive correlation between the percentage of Th17 cells in PF and the white blood cell count in PB was found in patients with endometriosis. Conclusion Targeting the activity of PF Th17 cells may have an influence on the proliferation of ectopic tissue and clinical manifestations of the disease.