Protein Carbonyls in Decidua and Placenta of Pre-eclamptic Women as Markers for Oxidative Stress

Enhanced levels of reactive oxygen species (ROS) and decreased levels of antioxidants may contribute to the development of pre-eclampsia. Protein carbonyls may be sensitive biomarkers for ROS-mediated protein damage, whereas the ferric reducing ability of plasma (FRAP) value may serve as marker for antioxidant capacity. Twenty-two healthy pregnant women and 50 patients with severe pre-eclampsia, 25 of whom with concurrent (haemolysis, elevated liver enzymes, low platelets) HELLP syndrome were investigated prospectively with respect to placental and decidual levels of protein carbonyls and FRAP antioxidant capacity. Measurements were evaluated using the Kruskal–Wallis or Mann–Whitney U -tests for comparison between groups, and the Wilcoxon signed-rank test for comparison within groups. Spearman's correlation tests were used for correlation analyses. Placental and decidual protein carbonyl levels were higher in pre-eclampsia with HELLP than in healthy pregnancy, whereas FRAP levels were lower. Differences between pre-eclampsia and healthy pregnancy showed the same trend, but did not reach statistical significance. In pre-eclampsia with HELLP syndrome carbonyl levels as well as FRAP levels were significantly higher in placenta as compared with decidua. Higher levels of protein carbonyls and lower antioxidant capacity in both placenta and decidua in pre-eclampsia with concurrent HELLP syndrome as compared to healthy pregnancy may indicate that considerable ROS-mediated damage occurs in this disorder.