Relationship of PON2 gene Ser311Cys polymorphism and serum paraoxonase activity with coronary artery disease in Turkish population

Objective: Paraoxonase-2 (PON2) is a cellular enzyme that has antioxidant properties similar to PON1, an HDL-associated serum enzyme playing an important role in the prevention of atherosclerosis. 1. The aim of this study is to investigate whether serum paraoxonase activity and PON2 Ser311Cys polymorphism are related to coronary artery disease and the extent of atherosclerosis. Methods: Blood specimens were collected from 131 individuals who had no coronary artery lesions angiographically and 110 individuals who had angiographically-documented coronary artery disease at several degrees. The extent and severity of arterial lesions were evaluated by Gensini scoring system. Paraoxonase and arylesterase activities were measured in serum using a spectrophotometric method. PON2 Ser311Cys polymorphism was evaluated using PCR-RFLP after DNA isolation from samples. Results: Serum paraoxonase and arylesterase activities were significantly lower in the patient group than controls (respectively, 135.6 +/- 55.4 U/ml vs 152.9 +/- 61.2 U/ml, p < 0.05 and 104.7 +/- 15.6 U/ml vs 121.6 +/- 25.7 U/ml, p < 0.01). There were negative correlation between serum paraoxonase, arylesterase activities and Gensini score (respectively, r=-0.183, p=0.005, r=-0.210, p-0.017). The distribution of PON2 Ser311Cys polymorphism between groups was not significant. There was no significant difference in Gensini scores according to genotypes, either. Conclusion: These results indicated that serum paraoxonase activity might be a more important marker than PON2 Ser311Cys polymorphism in evaluating the cardiovascular disease risk and the extent and severity of atherosclerosis.