Altered Distribution of CD14⁺ Macrophages and Reduced ROS Activity in Preeclamptic Placentas

Pregnancy requires a delicate balance between maternal immune tolerance and protective responses, with macrophages playing a pivotal role in placental development and immune regulation. Preeclampsia, a hypertensive disorder that affects 5%-8% of pregnancies, is associated with immune dysregulation, oxidative stress, and impaired placental remodeling.

In this study, we investigated the distribution of CD14⁺ and CD11b⁺ cells and the production of reactive oxygen species (ROS) in placental tissues from healthy pregnancies and preeclampsia cases, from areas near the umbilical cord and the delivery channel and divided into maternal, maternal/fetal and fetal zones, of each area.

Immunofluorescence analysis revealed that in healthy placentas, CD14⁺ macrophages were heterogeneously distributed with enrichment in the fetal section near the delivery channel, whereas in preeclamptic placentas these cells accumulated predominantly in the umbilical cord region. No significant differences were observed for CD11b⁺ cells, although a tendency toward increased numbers was noted in preeclamptic tissues. ROS analysis showed no statistically significant changes, but preeclamptic placentas exhibited weaker fluorescence intensity, indicating reduced ROS activity.

These findings suggest that altered CD14⁺ and CD11b⁺ cells localization, together with diminished ROS signaling, may contribute to the pathophysiology of preeclampsia by impairing immune regulation and placental vascular remodeling.