Interleukin-2 receptor positive cells in human decidua during the first trimester of pregnancy and their association with macrophages.

Maternal immune rejection of the fetus could sometimes be the cause of unexplained recurrent spontaneous abortion. Components of the T cell-mediated immunity were investigated in the first trimester of pregnancy in women having spontaneous abortion and compared to those with normal pregnancy having a termination on social grounds. Interleukin 2 (IL-2) had no proliferative effect on the trophoblasts of chorionic villi and there were also no IL-2 receptors in these cells. However IL-2 receptor positive cells were found in the decidua in 7 out of 24 women with normal pregnancy and in 12 out of 18 with spontaneous abortion. A high density of macrophages showed an association with IL-2 receptors in both groups. There were no differences with respect to T-cytotoxic cells and T-helper cells in cases of normal pregnancy (with and without IL-2 receptor positive cells), whereas in women having spontaneous abortion we found lower densities of T-helper and T-cytotoxic cells in those without IL-2 receptors than in those with IL-2 receptors.