Primary arteriopathy in Takayasu's disease

Three patients with classic Takayasu's arteritis affecting the aorta and its major branches were found to have a unique small pulmonary arteriopathy characterized by deficiency of the outer media, with capillary ingrowth both here and in the thickened fibrosed intima. In one patient there was also evidence of a mononuclear cellular arteritis of the affected arteries and widespread focal angiomatoid like lesions. Another patient had similar, but less well-defined dilatation lesions. This patient's major coronary arteries showed an active arteritis with ingrowth of reparative granulation tissue capillaries into both media and intima, yielding an appearance not dissimilar to that seen in the small pulmonary arteries. The outer pulmonary artery medial defects observed in our patients bear some similarity to experimental acute immune-complex arteritis and may thus provide tenuous evidence for an autoimmune basis for Takayasu's disease.