Characterization of inflammatory cells in a patient with chronic periaortitis.

During repair of an inflammatory abdominal aortic aneurysm, fresh samples of the aneurysm wall were obtained. Histology confirmed the diagnosis of chronic periaortitis,- advanced atherosclerosis with medial attenuation, and periaortic inflammation. Monoclonal antibodies were used to identify the cells of the inflammatory infiltrate. The majority of the adventitial lymphocytes were B cells. No B cells were present in the atheroma. The majority of mature plasma cells contained IgG with a few plasma cells containing IgM. T cells, predominantly T helper cells, were found in the atheroma and adventitia. Positive DR staining was shown by the majority of lymphocytes, by macrophage-like cells in germinal centers of lymphoid follicles in the adventitia, by some vascular endothelial cells, and by some smooth muscle cells. The implications of these findings are discussed.