Association of Human Monocytic Paraoxonse 2 (Pon 2) and Serum Nitric Oxide Levels in Preeclampsia Patients

Abstract

OBJECTIVE: Pre-eclampsia and atherosclerosis are both endothelial diseases with an involvement of lipid-mediated oxidative damage. The intracellular antioxidant enzyme paraoxonase 2 (PON2) may have a protective function in the prevention of atherogenesis. Oxidative stress have important role in the pathogenesis of pre-eclampsia. Study was designed to investigate monocytic paraoxonase 2 activity in pre-eclampsia. DESIGN AND METHOD: Study group was case-control study of 60 with preeclampsia and 60 uncomplicated term-deliveries. Paraoxonase2 activity done using substrate Dihydrocoumarin (DHC). RESULTS: Monocytic Paraoxonase2 activity was significantly lower in women with preeclampsia v/s controls (1.22U/mg versus1.67U/mg protein, p =0.002) Serum levels of T. chol, LDLc and VLDLc are higher in cases than in controls and are statistically significant. Serum nitric oxide also showed significant decrease in cases 22.92umol/L versus 25.12umol/L, p=0.015. In multivariate regression analysis PON2 (OR 2.393, p=0.002) and for nitric oxide (OR 1.091, p=0.030). Multivariate logistic regression analysis after adjustment of other risk factors demonstrates decreased PON2 lactonase activity is associated with greatest risk for preeclampsia. Model 1:, total cholesterol, HDL-C, LDL-C, nitric oxide ( R2=0.137, p= 0.011) , model 2 All parameters in Model I + PON2 lactonase activity. (R2=0.243, p<0.001). ROC plots demonstrated a high diagnostic accuracy for model 2 (area under ROC curve = 0.745) than model1 (area under ROC curve=0.686) CONCLUSION: decreased PON2 lactonase activity, abnormal lipid profile and decreased nitric oxide (nitrate+ nitrite) may have role in pathogenesis of pre-eclampsia and also gives valuable information regarding the risk prediction of pre-eclampsia.