Serum sFlt-1, cystatin C and cathepsin B are potential severity markers in preeclampsia: a pilot study

Preeclampsia is associated with abnormal invasion of the trophoblast through decidua and subsequently altered remodeling of the maternal spiral arteries and endothelial dysfunction. This phenomenon is explained by the dysregulation of various kinds of vascular factors and proteases. The purpose of this study was to compare the circulating levels of sFlt-1, cathepsin B, and cystatin C in preeclamptic and normotensive pregnancies.

Sixty-two pregnant women were enrolled in this prospective study. Twenty women were preeclamptic and 42 were normotensive. Serum levels of sFlt-1, cathepsin B, and cystatin C were measured using an enzyme-linked immunosorbent assay kit.

Circulating levels of sFlt-1, cathepsin B, and cystatin C were significantly higher in preeclamptic than in normotensive pregnant women (p < 0.001; p = 0.017; p = 0.003). Preeclamptic women with severe features demonstrated significantly higher levels of cathepsin B (p = 0.05). Serum sFlt-1 and cystatin C levels were positively correlated with elevated systolic and diastolic blood pressure. The levels of cathepsin B were positively correlated with alanine and aspartate aminotransferase. The amount of 24 h proteinuria was positively, but non-significantly correlated with sFlt-1 and cystatin C.

In addition to sFlt-1 levels, the serum levels of cathepsin B and cystatin C significantly change when preeclampsia develops. These markers are associated with severity markers of elevated blood pressure and liver injury in preeclampsia.