Plasma PP13 and urinary GAGs/PGs as early markers of pre-eclampsia

Abstract

Purpose: To evaluate at 11-13 weeks' gestation biochemical markers that may predict complications of pregnancy such as pre-eclampsia, proteinuria, and hypertension.

Methods: Analyses were performed on first-morning urine and plasma samples from first trimester pregnant women with increased risk of developing pre-eclampsia such as positive personal or family history of cardiovascular disease and diabetes mellitus. A total of 62 women were enrolled, 24 of them presented complications such as pre-eclampsia, proteinuria, and hypertension during pregnancy. The remaining 38 women had a physiological course of pregnancy and formed the reference group. Urine glycosaminoglycans/proteoglycans (GAGs/PGs) distribution was determined by electrophoresis on cellulose acetate strips. Urinary N-acetyl-β-glucosaminidase was estimated kinetically. Plasma levels of placental protein 13 (PP13) were measured by enzyme-linked immunosorbent assay.

Results: No significant differences in total GAG excretion and N-acetyl-β-glucosaminidase (NAG) concentration were observed between the two groups of pregnant women, whereas we detected increased relative content of total urinary trypsin inhibitor (UTI plus low-sulfated chondroitin sulfate) (p = 0.001) and reduced excretion of heparan sulfate (p = 0.007) and chondroitin sulfate (p = 0.011) in women presenting with pregnancy complications respect to controls. Plasma levels of PP13 were significantly reduced in the group of women who went on to develop complications compared with controls (p = 0.022).

Conclusions: The reduced plasma levels of PP13 and the alteration of the relative content of urinary GAGs and PGs observed in our study could be a promising tool for the prediction of pre-eclampsia in an early stage of pregnancy.

Keywords: Glycosaminoglycans (GAGs); Placental protein 13 (PP13); Pre-eclampsia; Proteoglycans (PGs).