RESUMEN
INTRODUCTION: Endometriosis constitutes the growth of endometrial tissue in a place other than the uterine cavity. Its etiopathogenesis is unknown, although there is some evidence associating it with the decrease of cytotoxic activity in the immunological system. OBJECTIVE: Evaluating the relationship between the development of ectopic endometrial tissue and the immunological status, and enumerating lymphocyte subpopulations and cytokine synthesis in T lymphocytes, using a murine endometriosis model. METHODOLOGY: Spleen lymphocytes isolated from two study groups of 10 female mice of the Balb/c strain that had been submitted to the surgical implantation of autologous endometrial tissue in the peritoneal cavity, and sacrificed after 5 (group I) and 8 (group II) weeks, were incubated--or not--with PMA/lonomicine. Lymphocyte T numbers and their cytokine production were determined by flow cytometry. RESULTS: A lower dispersion of the ectopic tissue growth value was observed in group II (24 vs. 42). A smaller population of cytotoxic T lymphocytes and a greater IL-4 production in the stimulated cells of the study group (p < 0.05) were observed, as compared to the control group. CONCLUSIONS: The presence of endometrial tissue in the uterine cavity decreases the amount of cytotoxic T lymphocytes and increases IL-4 production in total T lymphocytes, suggesting a modulation of the systemic immunological response to TH-2.