Objective: To measure the concentration of plasma soluble angiotensin IV receptor (sAT-4), a component of the renin-angiotensin system in healthy normotensive pregnancies and preeclampsia.
Study design: Stored maternal plasma samples obtained at the time of diagnosis from pregnant women of African ancestry were stratified into normotensive and preeclampsia groups. Preeclampsia was subdivided into early-onset, late-onset, and into and severe preeclampsia. Plasma concentrations of sAT-4 were measured at 450 nm using the ELISA technique (LNPEP KIT).
Results: The systolic and diastolic blood pressure (BP) levels of the normotensive group were statistically lower compared to preeclampsia groups (p < .05) and the mean gestational age in early-onset preeclampsia was lower compared to late-onset preeclampsia and the normotensive group (p < .05). Plasma sAT-4 levels were significantly elevated (p < .0001) in the normotensive group (median 1.95, range 1.89-2.02 ng/ml) compared to the preeclampsia group (median 1.55, range 1.42-1.74 ng/ml), regardless of gestational age. Soluble AT-4 was decreased in relation to the severity of preeclampsia (p < .001), the level in preeclampsia without severe features (median 1.57, range 1.42-1.74 ng/ml) was significantly higher than in preeclampsia with severe features (median 1.51, range 1.42-1.55 ng/ml). There was no significant difference in the sAT-4 level between early-onset preeclampsia (1.60 ± 0.13 ng/ml) and late-onset preeclampsia (1.65 ± 0.29 ng/ml) groups (p = .59).
Conclusion: Plasma circulating levels of sAT-4 in women with severe features of preeclampsia had lower levels than normotensives and those with preeclampsia without severe features.
Keywords: Preeclampsia; renin-angiotensin-aldosterone system; soluble angiotensin IV receptor (sAT-4).