Distribuição de macrófagos, linfócitos Te linfócitos B nas vilosidades placentárias de gravidezes humanas a termo

Abstract

The placenta contains histoincompatible cells derived from mother and fetus. Despite intense investigation, it is poorly understood why the fetus and the placenta are not rejected by maternal immune system. The fetus can be considered a successful allograft. Macrophages and Lymphocytes can be found in the decidua and in the chorionic villous mesenchyme of placenta throughout pregnancy. Although there is general agreement about the existence of immune system cells within the placental chorionic villous mesenchyme, there are contradictory data regarding the relative percentage of macrophages and lymphocytes among the placental cell population. In this research, thirty one placentas were studied by immunohistological technique. Twenty human term placentas (64,5%) were collected from normal vaginal deliveries and eleven placentas (35,5%) were from elective cesarean sections. The frequency and distribution of macrophages, T lymphocytes and B lymphocytes in chorionic villous mesenchyme of human term placentas were quantified and analyzed. Placenta cryostat sections were labeled using a panei of monoclonal antibodies specific for CD68, CD43 and CD20; and using avidin-biotin complex peroxidase method. In our results, the macrophages (CD68+), T lymphocytes (CD43+) and B lymphocytes (CD20+) comprised 17%, 4,9% and 0,81% of the cell population in chorionic vilous stroma, respectively. About the percentage of macrophages in chorionic vilous, the placentas were different and the range of variation was from 4,51% to 63,03%. We conclude that macrophages were more frequent than T lymphocytes and B lymphocytes. The B lymphocytes were rare in chorionic vilous stroma. And we didn't fínd change in percentage of these cells in association with labor.