Accumulation of lymphocytes, dendritic cells, and granulocytes in the aortic wall affected by Takayasu's disease

The aim of this study was to analyze the cellular composition of the arteri al wall in Takayasu's disease and to investigate the contribution of the va rious cell types to the immunoinflammatory processes and degenerative alter ations of the vessel wall in this disease. Specimens of aorta were obtained at operation from 10 patients with Takayasu's arteritis. The duration of d isease ranged from 2 months to 13 years. Immunohistochemical investigation was carried out using the antibodies CD3 (to identify T-cells), CD20 (B-cel ls), S-100 (dendritic cells), CD68 (macrophages), CD15 (granulocytes), von Willebrand factor (endothelial cells), and alpha-smooth muscle actin (smoot h muscle cells). All specimens showed distinctive histologic features of Ta kayasu's arteritis and contained inflammatory infiltrates, but the degree o f their accumulation within the aortic wall varied. Inflammatory infiltrate s within the deep part of the intima, around areas of neovascularization an d within the adventitia contained T-cells colocalizing with dendritic cells . Nodules formed by large numbers of intermingling T-cells and B-cells enri ched with dendritic cells were observed in the adventitia, Massive accumula tion of granulocytes and their destruction within the adventitia were promi nent in all cases. This is the first study that establishes the presence of dendritic cells and granulocytes in Takayasu's disease. Dendritic cells ar e probably involved in the immunoinflammatory processes through their inter action with T-cells and B-cells. The present observations may help understa nding of the pathogenesis of Takayasu's disease.