Lymphocyte subset distribution and cytokine secretion in third trimester decidua in normal pregnancy and preeclampsia.

BACKGROUND

Excessive Th1 activity in peripheral blood plays a probable role in the pathogenesis of preeclampsia. The aim of the study was to investigate whether disturbed local immune reactions are also present in decidua.

METHODS

Flow cytometric analysis of CD3, CD19, CD56/CD16, CD4, CD8, CD4/CD29, CD4/CD45RA, CD4/CD45RO, CD8/CD28, CD3/CD69 lymphocyte subsets isolated from third trimester decidua of pregnants with preeclampsia (n=21) and pregnant controls (n=11) subjected to elective caesarean sections. Spontaneous and phytohemaglutynine stimulated "in vitro" secretion of IL-2, IL-4, IL-6, IL-10, IL-12, IFN-gamma and TGF-beta by decidual lymphocytes was studied by ELISA. For the statistical significance of differences between the groups the U Mann-Whitney test was performed (confidence interval P<0.05).

RESULTS

Preeclamptic patients were characterized with an increased percentage of the CD3-/CD56+CD16+, CD8+/CD28+ and decreased percentage of CD3+, CD19+, CD4+/CD45RA+ lymphocytes. The profile of secreted cytokines shifts in favor of Th1 activity (extremely high IFN-gamma and low IL-6 and IL-10 secretion). Decidual IL-12 secretion in preeclamptic patients is decreased compared to controls.

CONCLUSION

Changes in NK and T lymphocyte subsets followed with Th1 cytokine IFN-gamma over-activity, could affect local immunoregulatory mechanisms in third trimester decidua of preeclamptic patients.