Association between myeloperoxidase polymorphisms and its plasma levels with severity of coronary artery disease.

OBJECTIVES: Myeloperoxidase (MPO) polymorphism -463 has been related to higher cardiovascular risk. This study was conducted to test whether the MPO promoter polymorphism -463A/G and MPO plasma levels are associated with coronary artery disease (CAD) severity. DESIGN AND METHODS: Patients submitted to elective coronariography were enrolled, CAD severity was assessed and blood samples collected to identify the MPO polymorphism and its plasma levels. RESULTS: Genotypes were determined in 118 patients. Among these patients, 12 (10%) were homozygous for AA, 69 (58%) for GG and 37 (32%) were heterozygous. Mean MPO plasma levels were 8.6+/-4.7 ng/mL for AA, 8.6+/-7.0 ng/mL for AG and 9.4+/-5.6 ng/mL for GG genotypes. The CAD severity was not associated with MPO genotypes (p=0.43), however, patients with higher CAD score presented higher MPO levels (p=0.02). CONCLUSION: We found no association between MPO polymorphism and CAD severity, although a relation was observed for MPO plasma levels and extension of CAD.