Increased expression of interleukin-10 in unstable plaque obtained by directional coronary atherectomy

Abstract

Aims The present study investigates the expression and localization of interleukin (IL)-10, an important anti-inflammatory cytokine, in atherectomy specimens from patients with stable and unstable angina. Methods and results Twenty-two patients with stable angina and 21 with unstable angina who underwent directional coronary atherectomy for de novo lesions were studied. The atherectomy specimens were morphologically assessed and immunohistochemically stained with antibodies for IL-10, macrophages, smooth muscle cells, and endothelial cells. The localization and immunopositive areas were evaluated using an image analysing system. Immunoreactivity for IL-10 was detected in coronary plaques, especially in macrophages. Immunopositive areas of macrophages and IL-10, as well as the incidence of thrombus formation, were significantly greater in specimens from patients with unstable angina than in those from patients with stable angina (macrophages, PPPPConclusion IL-10 was more frequently expressed in specimens from patients with unstable angina. This finding might contribute to a better understanding of plaque instability.