Determining Disease Activity Biomarkers in Individuals With Takayasu's Arteritis

Takayasu's arteritis is a chronic inflammatory condition that affects the aorta, the largest blood vessel in the body, and its branches. Inflammation causes segments of the vessels to become narrowed, blocked, or even stretched, possibly resulting in aneurysms. The disease is very rare but most commonly occurs in young Asian women. Symptoms may include arm pain with use, decreased or absent pulses, lightheadedness or dizziness, headaches, and visual disturbances. Many individuals with Takayasu' arteritis, however, have no apparent symptoms despite disease activity. Additionally, current tests used to measure vessel inflammation are considered unreliable and inconsistent. It is therefore very difficult to determine the extent of disease activity in a person with Takayasu's arteritis. This study will use novel scientific methods to establish new biomarkers that can be used to monitor disease activity in individuals with Takayasu's arteritis. These biomarkers may be used to help direct clinical care and assist in future drug development.

Study visits will occur monthly for the first year, then every 3 months thereafter for the remainder of the study. Blood and urine collection will occur at every visit. A physical examination, disease assessment, and review of medications will occur every 3 months; participants may also be asked to complete various questionnaires. Diagnostic testing, which may include chest radiograph, echocardiogram, magnetic resonance imaging, or angiography, will occur every 6 months. Tobacco, alcohol, and drug use will be assessed on a yearly basis. Participants may have additional study visits if a disease flare or disease-related complications occur during the study.

Inclusion criteria

• Evidence of arteriogram abnormalities compatible with Takayasu's arteritis (includes conventional dye angiography, magnetic resonance angiography, or computed tomography angiography)
• Evidence of one of the following criteria:

• Age at disease onset of 50 years or younger
• Claudication of the arms or legs
• Decreased brachial artery pulse (one or both arteries)
• Blood pressure difference between the arms of at least 10 mm Hg
• Bruit over the subclavian arteries or aorta
• Parental consent for children under the age of 18

Exclusion criteria

• Arteriographic lesions that could be entirely due to atherosclerosis
• Fibromuscular dysplasia
• Cogan's syndrome
• Behcet's disease
• Sarcoidosis
• Kawasaki disease
• Giant cell arteritis (large vessel vasculitis and at least 50 years old)
• Syphilis or other infectious forms of large vessel vasculitis