Determinazione dell’acido urico nelle placche carotidee: possibile mediatore dell’ aterosclerosi? Determination of uric acid in carotid artery plaque:a possible mediator of atherosclerosis?

Background. In this work we determined uric acid (UA), an antioxidant that enhances in oxidative stress, in atheromatous plaque, characterized by this phenomenon, to improve our knowledge of oxidative stress and to show a possible correlation between biochemical and ultrasonographic plaque characterization. We have also analyzed UA in the plasma of the same subjects to show a possible correlation between plasma and plaque UA levels. This could help us to study plaque evolution. Methods. Surgical specimens and plasma were obtained from patients (symptomatic and asymptomatic) undergoing carotid endoarterectomy. Plaque was characterized by duplex scan. UA was determined by high performance liquid chromatography (HPLC). Results. Concentrations of UA were much lower in plaque (10.3±2.2 μg/g) than in plasma (48.7±2.4 μg/ml). There was no correlation between UA plasma levels and UA in plaque. There were no differences of UA in the different groups analyzed. Conclusions. UA seems to have a direct role in atherosclerosis. The absence of correlation between UA plasma level and UA in plaque should confirm that UA in plaque is not due to accumulation from plasma, but a local intrinsic phenomenon of intimal disease space. Actually, it is impossible, considering the restricted case number, to say that UA plasma levels can help in the study of plaque evolution.