Changes in endothelial progenitor cell subsets in normal pregnancy compared with preeclampsia

Area of Science:

• Reproductive biology
• Vascular biology
• Cellular immunology

Background:

• Endothelial progenitor cells (EPCs) play a crucial role in vascular health.
• Previous studies on EPC subsets in normal pregnancy and preeclampsia yielded conflicting results due to diverse methodologies.
• Three main EPC subsets include circulating angiogenic cells (CACs), colony-forming unit endothelial cells (CFU-ECs), and endothelial colony forming cells (ECFCs).

Purpose of the Study:

• To reconcile controversial findings on EPC subset counts in pregnancy.
• To prospectively compare EPC subsets across normal pregnancy trimesters.
• To investigate EPC subset differences in preeclampsia versus gestational age-matched controls.

Main Methods:

• Quantitative flow cytometry was used to enumerate 13 cell populations for CACs and ECFCs, utilizing markers like CD34, CD133, CD309, and CD45.
• Routine culturing techniques were employed to quantify CFU-ECs.
• Peripheral blood samples were collected from nine women in three trimesters of normal pregnancy and eight women with preeclampsia.

Main Results:

• Women with preeclampsia exhibited higher numbers of CACs and ECFCs (p = 0.014) but fewer CFU-ECs (p = 0.039) compared to controls.
• In normal pregnancy, CAC numbers increased with gestational age (p = 0.016), while CFU-EC and ECFC counts remained stable across trimesters.
• Increased CACs and ECFCs in preeclampsia were associated with reduced colony formation capacity, suggesting impaired function.

Conclusions:

• Preeclampsia is characterized by an increase in CACs and ECFCs, but a decrease in functional CFU-ECs.
• Normal pregnancy involves a rise in CACs correlating with fetal development, without affecting CFU-EC or ECFC numbers.
• Comparing methodologies for EPC subset enumeration clarifies existing literature controversies and highlights functional differences in these cells during pregnancy and preeclampsia.