Lipid hydroperoxides and free radical scavenging enzyme activities in preeclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome: No evidence for circulating primary products of lipid peroxidation

OBJECTIVE: Preeclampsia is reportedly accompanied by increased plasma lipid peroxidation. However, to date the assays that have been applied to measur e lipid peroxides have been relatively nonspecific, A highly specific high- performance lipid chromatographic-chemi luminescence technique was used her e to measure lipid hydroperoxides in plasma and red blood cells of patients with preeclampsia and HELLP (hemolysis, elevated liver enzymes, and low pl atelet count) syndrome. STUDY DESIGN: Lipid peroxidation products, both lipid hydroperoxides and th iobarbituric acid reactive substances (TBARS), and free radical scavenging enzyme activities were measured in either plasma or erythrocytes of patient s with normal pregnancies (n = 36), preeclampsia (n = 28), or HELLP syndrom e (n = 10). RESULTS: Whereas lipid hydroperoxides were undetectable (<0.02 mu mol/L), p lasma TBARS and glutathione peroxidase activity in plasma and erythrocytes were significantly increased in patients with HELLP syndrome. There were no differences in glutathione transferase and reductase activities or superox ide dismutase activity between the groups. CONCLUSIONS: We were unable to corroborate results of studies that suggeste d that increased TBARS are representative of circulating plasma lipid hydro peroxides in preeclampsia, However, elevated glutathione peroxidase activit y and TBARS are in line with increased oxidative stress in preeclampsia.