Osteoprotegerin and Osteopontin Are Expressed at High Concentrations Within Symptomatic Carotid Atherosclerosis

Background and Purpose— The aim of this study was to compare the concentration of osteoprotegerin (OPG), receptor activator of nuclear factor κB ligand (RANKL), and osteopontin (OPN) in stable (asymptomatic) and unstable (symptomatic) carotid atherosclerosis. In addition, we were interested in the effect of angiotensin II blockade on the secretion of these proteins by unstable atherosclerosis. Methods— Endarterectomy samples removed from patients with recent (within 6 weeks) or no previous focal neurological symptoms were assessed by immunohistochemistry, Western analysis, and explant culture. Concentrations of OPG, RANKL, and OPN were measured by mean optical density (MOD), densitometry of protein bands, and enzyme-linked immunosorbent assay of supernatants from explant culture, and compared between symptomatic and asymptomatic patients. Results— The concentration of OPG and OPN within the proximal internal carotid (PIC) part of the endarterectomy specimen removed from symptomatic patients was elevated 2...