Comparative Analysis of Immune Cell Populations From Two Sampling Techniques of Human Term Decidua Utilizing...

The decidua is the interface between the uterus and the fetus. Studying decidual cells can reveal how healthy pregnancies are supported and mechanisms of pregnancy complications. There are two methods of obtaining decidual tissue following delivery. The placental bed can be suctioned following C-section deliveries, or a thin layer of decidual tissue can be dissected from the placenta. This study aimed to compare immune cell populations obtained using the two methods.

From individuals with scheduled C-sections, we collected peripheral blood, decidua via vacuum suction of the placental bed, and decidua via dissection of the uterine-facing side of the placenta. Samples were analyzed using a 22-color full-spectrum flow cytometry panel to identify immune cell subsets and functional markers.

The cellular composition of both decidual tissue collection methods were more similar to each other than to peripheral blood. Decidua collected via vacuum suction (Suc. decidua) had more live CD45+ cells. Decidua collected via dissection of the uterine-facing side of the placenta (Plac. decidua) had significantly higher expression of Helios in CD4+ cells, suggesting more fetal T cells. Both types of decidual samples contained similar levels of Tr1-like regulatory T lymphocytes expressing LAG3 and CD49b, whereas peripheral blood did not have this cell type.

Collecting decidual tissue using either method resulted in largely similar immune cell populations, suggesting studies are largely comparable regardless of whether samples were collected via suction or placental dissection. This will allow for greater flexibility in sample collection methods.