Plasma P-selectin is elevated in the first trimester in women who subsequently develop pre-eclampsia

OBJECTIVE

To report plasma concentrations of the adhesion cell molecule P-selectin during pregnancy to determine the effect of subsequent development of hypertension and pre-eclampsia.

DESIGN

A longitudinal study.

METHODS

A longitudinal study involving 70 women followed up from early pregnancy; 20 who subsequently developed pre-eclampsia were compared with 24 who developed gestational hypertension and 26 normotensive women with normal obstetric outcome. The determination of citrate plasma soluble P-selectin levels throughout pregnancy was performed using a commercial quantitative sandwich immunoassay kit. The temporal course of plasma P-selectin in the three groups of subjects was analysed.

RESULTS

There was no significant difference in mean plasma P-selectin concentration between normotensive and gestational hypertensive subjects at any stage of pregnancy. Using a cutoff level of 60 ng/mL, P-selectin concentration at 10-14 weeks had a negative predictive value for pre-eclampsia of almost 99%. Mean plasma P-selectin concentrations were significantly elevated by 10-14 weeks in women who later developed pre-eclampsia (P < 0.001).

CONCLUSIONS

Our data support an inflammatory model for pre-eclampsia whereby endothelial cell activation may be secondary to a primary inflammatory response. Plasma P-selectin has significant potential as a first trimester clinical marker of pre-eclampsia.

Plasma P-selectin is elevated in the first trimester in women who subsequently develop pre-eclampsia

OBJECTIVE

To report plasma concentrations of the adhesion cell molecule P-selectin during pregnancy to determine the effect of subsequent development of hypertension and pre-eclampsia.

DESIGN

A longitudinal study.

METHODS

A longitudinal study involving 70 women followed up from early pregnancy; 20 who subsequently developed pre-eclampsia were compared with 24 who developed gestational hypertension and 26 normotensive women with normal obstetric outcome. The determination of citrate plasma soluble P-selectin levels throughout pregnancy was performed using a commercial quantitative sandwich immunoassay kit. The temporal course of plasma P-selectin in the three groups of subjects was analysed.

RESULTS

There was no significant difference in mean plasma P-selectin concentration between normotensive and gestational hypertensive subjects at any stage of pregnancy. Using a cutoff level of 60 ng/mL, P-selectin concentration at 10-14 weeks had a negative predictive value for pre-eclampsia of almost 99%. Mean plasma P-selectin concentrations were significantly elevated by 10-14 weeks in women who later developed pre-eclampsia (P < 0.001).

CONCLUSIONS

Our data support an inflammatory model for pre-eclampsia whereby endothelial cell activation may be secondary to a primary inflammatory response. Plasma P-selectin has significant potential as a first trimester clinical marker of pre-eclampsia.

Maternal plasma vascular endothelial growth factor concentrations in normal and hypertensive pregnancies and their relationship to peripheral vascular resistance

OBJECTIVE

The aim of this study was to measure maternal plasma vascular endothelial growth factor concentrations during normal and hypertensive pregnancies and examine their relationship with maternal total peripheral resistance values.

STUDY DESIGN

Plasma concentrations of total immunoreactive vascular endothelial growth factor and total peripheral resistances were measured serially throughout pregnancy in 20 women with preeclampsia, 24 women with gestational hypertension, and 26 normotensive control women. One-way analysis of variance and a regression model were used to analyze the vascular endothelial growth factor levels in the groups and the relationship between vascular endothelial growth factor concentration and total peripheral resistance.

RESULTS

At 10 to 14 weeks' gestation plasma vascular endothelial growth factor concentrations in all subjects were 4 to 5 times greater than the levels measured post partum (P <.0001). Mean vascular endothelial growth factor concentrations were similar in the control and gestational hypertension groups; in both groups levels remained stable until 34 to 36 weeks' gestation, when levels increased a further 1.3-fold (P <.01). In comparison, vascular endothelial growth factor concentrations in subjects in the preeclampsia group were greater at 28 to 32 weeks' gestation (P =.002) and at 34 to 36 weeks' gestation (P <.001). Vascular endothelial growth factor concentrations were also increased during the 4 weeks that preceded the diagnosis of preeclampsia (P <.05). Vascular endothelial growth factor concentrations were associated with the elevated total peripheral resistance observed during the clinical disorder in the preeclampsia group but not in the other groups.

CONCLUSION

Maternal plasma vascular endothelial growth factor concentrations increased before the clinical onset of preeclampsia and were further elevated during the vasoconstricted state observed in this disorder. We speculate that the hyperdynamic circulation that characterizes the latent phase of preeclampsia causes vascular shear stress, which in turn increases the levels of circulating vascular endothelial growth factor. Because vascular endothelial growth factor normally acts as a vasodilator, its increase may represent an unsuccessful vascular rescue response.

Maternal central hemodynamics in hypertensive disorders of pregnancy

OBJECTIVE

To document maternal central hemodynamics during the preclinical and clinical phases of nonproteinuric gestational hypertension and preeclampsia.

METHODS

We conducted a longitudinal study of 400 primigravidas who were monitored throughout pregnancy using Doppler echocardiography. Multinomial logistic regression was used to identify variables associated with risk of hypertension.

RESULTS

Gestational hypertension developed in 24 women and preeclampsia developed in 20. Compared with normotensive controls, women who had preeclampsia had significantly elevated cardiac outputs before clinical diagnosis, but total peripheral resistance was not significantly different during this latent phase. During the clinical phase of preeclampsia, there was a marked reduction in cardiac output and increase in peripheral resistance. All women who had gestational hypertension had significantly elevated cardiac outputs before and during the clinical course of the condition.

CONCLUSION

Our data support the concept of a hyperdynamic disease model for preeclampsia, with a subsequent hemodynamic crossover to low cardiac output and high resistance circulation coinciding with the onset of the clinical syndrome. Women with gestational hypertension had no such hemodynamic crossover and maintained hyperdynamic circulation throughout pregnancy.