Syncytiotrophoblast-derived microparticle shedding in early-onset and late-onset severe pre-eclampsia.

Objective: To determine the concentration of syncytiotrophoblast-derived microparticles (STBMs) in the maternal circulation and the rate of syncytiotrophoblast apoptosis in the placenta of patients with early-onset and late-onset severe pre-eclampsia.

Methods: A prospective case-control study was conducted that enrolled 15 women with early-onset severe pre-eclampsia, 15 women with late-onset severe pre-eclampsia, and 10 women with normal pregnancies. Plasma STBM levels were measured by enzyme-linked immunosorbent assay, while placental levels of active caspase-3 were determined by western blotting. Human umbilical vein endothelial cells (HUVECs) were cultured with STBMs and the proliferation and apoptosis rates of the HUVECs assessed.

Results: Levels of STBMs in the early-onset group (71.2 ± 20.7 ng/mL) were significantly higher than those detected in the late-onset group (41.9 ± 29.7 ng/mL) and the control group (26.3 ± 11.2 ng/mL) (P<0.05). The amount of active caspase-3 was increased in the early-onset (0.85 ± 0.61) and late-onset groups (0.77 ± 0.46) relative to the control group (0.32 ± 0.15) (P<0.05). Proliferation of HUVECs was inhibited, while apoptosis was elevated, following co-culture with STBMs.

Conclusion: Shedding of STBMs into the maternal circulation occurs in greater amounts in early-onset pre-eclampsia than in late-onset pre-eclampsia.