Perforin-expressing lymphocytes in peripheral blood and decidua of human first-trimester pathological pregnancies.

Problem: We have shown previously that the decidua of first-trimester human pregnancy is heavily infiltrated with perforin-positive cells. The aim was to detect expression of perforin in both decidual lymphocytes (DL) and peripheral blood lymphocytes (PBL) in the first trimester of pathological pregnancies: Anembryonic pregnancy and missed abortion.
Method: Decidual tissue from a normal pregnancy group and from pathological pregnancies was obtained by vaginal curettage. Perforin (an intracellular antigen) and the cell surface antigens CD3, CD4, CD8, CD16, CD56, CD11c, and CD45RA were quantified simultaneously by flow cytometric analysis.
Results: In the missed abortion group, we found: 1) a relative decrease in the frequency of both CD4+P+ cells and CD56+P+ cells as well as the mean fluorescence intensity for perforin; 2) a relative increase of CD16+P+ PBL cells; and 3) a relative increase of CD4+ cells in PBL compared with anembryonic pregnancy and normal pregnancy. There was also a significant relative decrease in the proportion of CD4+ and CD8+ cells among perforin-positive PBL in both anembryonic pregnancy and missed abortion.
Conclusion: Our results show that significant decreases in the prevalence of perforin-positive lymphoid cells, their subpopulations, and mean fluorescence intensity for perforin are associated with pregnancy failure.