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.
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.
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.
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.