Abstract 952: Increased Expression of Oxidative Stress Protein Myeloperoxidase in Diabetes Mellitus Atherosclerosis: Implications in Plaque Vulnerability
Introduction: Myeloperoxidase (MPO) is a heme peroxidase superfamily involved in the generation of oxidative stress, and is a now considered a biomarker to predict cardiovascular events in the general popultion. Patients with Diabetes Mellitus (DM) may have increased MPO expression. However, no data of plaque tissue expression of MPO in DM are currently available. We tested the hypothesis that MPO protein expression is increased in aortic plaques from patients with DM in areas of plaque vulnerability (fibrous cap/plaque shoulders and necrotic core).
Methods: 23 DM aortic plaques and 17 non-DM plaques were obtained at autopsy. MPO protein expression (immunohistochemistry) was scored as follows:0= absent, 1= weakly positive, 2= moderately positive; and 3= densely positive. A total of 20 high-power fields per plaque, 10 at the fibrous cap/shoulder and 10 at the necrotic core were used for comparisons.
Results: Myeloperoxidase protein expression was increased in DM plaques Vs. non-DM plaques at the fibrous cap/shoulder region (1.98 ± 0.09 Vs. 0.47 ± 0.13; p= 0.0001). In addition, MPO was also increased in DM plaques Vs. non-DM plaques (1.65 ± 0.10 Vs. 0.24 ± 0.10; p= 0.0001) at the necrotic core, as seen in Figure⇓.
Conclusion: Myeloperoxidase protein expression is increased in atherosclerotic plaques from patients with diabetes mellitus in specific areas of plaque vulnerability. These results support MPO as a biomarker in DM, and provide the basis for novel molecular imaging characterization to improve risk stratification in patients with diabetes atherothrombosis.