Aberrant expression of CD95 and CD69 molecules among CD56+ cells in women with endometriosis

Problem Activated lymphocytes can be eliminated by Fas/Fas ligand (FasL)-induced cell death. Endometrial cells express FasL. The aim of our study was to determine the expression of CD56(+) cells (natural killer and natural killer T cells) Fas antigen CD95 and the early activation molecule CD69 in the peritoneal fluid of women with endometriosis. Method Two-colour flow cytometry was used. Results In the early stages of endometriosis, more CD56(+) cells expressed CD69 and CD95 molecules when compared with the control group. However, in case of severe endometriosis the percentage of CD95(+)CD56(+) cells in peritoneal fluid was similar to that of the control group, but the expression of CD69 molecules remained high. Conclusion Because of Fas/FasL mechanisms, in the initial stages of endometriosis the activated peritoneal fluid CD56(+) cells can be intensively eliminated, thus providing conditions for the survival of ectopic endometrial cells and the development of the disease.