China Takayasu Arteritis Registry (CTA Registry)

Inclusion Criteria: * Age at disease onset \< 40 years. (Development of symptoms or findings related to Takayasu arteritis at age \<40 years) * Claudication of extremities. (Development and worsening of fatigue and discomfort in muscles of 1 or more extremity while in use, especially the upper extremities) * Decreased brachial artery pulse. (Decreased pulsation of 1 or both brachial arteries) * BP difference \>10 mm Hg. (Difference of \>10 mm Hg in systolic blood pressure between arms) * Bruit audible on auscultation over 1 or both subclavian arteries or abdominal aorta. * Arteriogram abnormality. (Arteriographic narrowing or occlusion of the entire aorta, its primary branches, or large arteries in the proximal upper or lower extremities, not due to arteriosclerosis, fibromuscular dysplasia, or similar causes; changes usually focal or segmental) Exclusion Criteria: * Vessel lesions that could be entirely due to atherosclerosis. * Giant cell arteritis or other infectious forms of large vessel vasculitis.