Background: Chronic periaortitis includes idiopathic retroperitoneal fibrosis, inflammatory aneurysms of the abdominal aorta, and perianeurysmal retroperitoneal fibrosis. It is considered to be due to advanced atherosclerosis, but is often associated with systemic autoimmune disorders.
Methods: We studied 16 consecutive patients who were diagnosed with chronic periaortitis by computed tomography. Each patient underwent a physical examination, routine laboratory tests, measurement of autoantibodies, thyroid echotomography, and chest radiography. Aortic wall or periaortic retroperitoneal samples from 9 patients who underwent surgery were available for histologic examination and immunohistochemical characterization of the inflammatory infiltrate.
Results: Twelve patients had constitutional symptoms, 14 had an elevated erythrocyte sedimentation rate, and 13 had an elevated C-reactive protein level. Antinuclear antibodies were positive in 10 patients. Three patients had autoimmune thyroiditis, and 1 had seropositive rheumatoid arthritis. Antineutrophil cytoplasmic antibodies were positive in 3 patients who presented with rapidly progressive renal failure. Pathologic examination of the aortic and periaortic specimens revealed moderate to severe inflammatory infiltration, mainly consisting of B cells and CD4(+) T cells. Vasculitis with fibrinoid necrosis involving the aortic vasa vasorum and the small and medium retroperitoneal vessels was found in seven of the nine histologic samples.
Conclusion: These clinical and pathologic features support the hypothesis that, at least in some patients, chronic periaortitis is a systemic autoimmune disease, perhaps involving a vasculitic process of small and medium vessels.