Higher Plasma AOPP is Associated with Increased Proteinuria Excretion and Decreased Glomerular Filtration Rate in Pre-eclamptic Women

Background: Advanced oxidation protein products (AOPP) as a novel biomarker of oxidative stress has been demonstrated in chronic kidney disease (CKD) patients. The research was to investigate the plasma AOPP level in pre-eclamptic pregnant women and its correlation with 24-h proteinuria collection, cystatin C(CC), uric acid(UA) and creatinine(Cr).

Methods: Fifty pre-eclamptic women, including 22 mild and 28 severe preeclampsia were enrolled. Twentyfive healthy singleton pregnant women were selected as control. Blood samples were obtained from all groups to measure the levels of AOPP, CC, UA, Cr and other biochemical parameters at admission. Total protein in the 24h urine collection was measured. Pearson correlation was performed to evaluate the associations between plasma AOPP level and 24-h proteinuria collection, plasma cystatin C, uric acid and creatinine.

Results: The means of AOPP levels were significantly different among severe, mild pre-eclampsia and normotensive pregnant women (88.6±10.0μmmol/L, 72.1±11.1μmmol/L and 48.7±11.3μmmol/L). The means of cystatin C levels were significantly different among severe, mild pre-eclampsia and normotensive pregnant women (1.8±0.6μmmol/L, 1.2±0.3μmmol/L and 1.0±0.2μmmol/L). Mild, severe pre-eclampsia and control groups did not differ significantly from each other with respect to uric acid and creatinine. Significant positive correlation between AOPP and 24-h proteinuria excretion in preeclamptic pregnant women was found in mild and severe preeclamptic pregnant women (r=0.792). Significant positive correlation between AOPP and cystatin C was found in normal and preeclamptic pregnant women (r=0.521).

Conclusion: Plasma AOPP level had a significant positive correlation with 24-h proteinuria excretion and cystatin C. Further research about the relevance between the level of AOPP and the onset of preeclampsia was needed in order to have a profound prospective in oxidative stress and preeclampsia.