Preeclampsia is associated with placental complement C4d deposition

Abstract

Introduction

Preeclampsia complicating pregnancy can be life-threatening for both mother and infant, often resulting in maternal and neonatal morbidity. Previous studies have related changes in specific immune factors to preeclampsia; however, the role of the complement system in preeclampsia remains understudied. Therefore, this study aims to examine differences in placental complement deposition in pregnancies complicated by preeclampsia and healthy term control pregnancies. In addition, we compared early and late preeclampsia with healthy term and spontaneous preterm births.

Methods

Placentas from pregnancies complicated by early onset preeclampsia (n = 26), late onset preeclampsia (n = 26), healthy term controls (n = 24), and spontaneous preterm births (n = 14) were investigated for the presence of complement using immunohistochemistry for C1q, C4d, C3d, C5b-9, and CD59.

Results

Deposition of C4d was observed at the trophoblast in 25.5 % of all preeclampsia cases and differed from healthy term controls (p = 0.029). C4d was observed in 12.0 % of late onset preeclampsia and 38.5 % of early onset preeclampsia placentas. None or minimal C4d was found in placentas of healthy term and preterm births. C4d trophoblast deposition significantly differed between early onset preeclampsia and healthy term (p = 0.002) and spontaneous preterm births (p = 0.022). With respect to C1q, C3d, C5b-9 and CD59, no significant differences were observed between the groups.

Conclusion

Our data demonstrate an increase in C4d deposition in placentas of early onset preeclampsia compared to healthy term controls and spontaneous preterm births, suggesting a possible role for the complement system in preeclampsia. Our findings underscore the complexity of preeclampsia pathophysiology and highlight the need for more refined, subtype-specific investigations.