Extra-cranial giant cell arteritis and Takayasu arteritis: How similar are they?

OBJECTIVE: To compare clinical and imaging characteristics of patients with giant cell arteritis (GCA) and upper extremity (UE) arterial involvement to patients with Takayasu arteritis (TAK). METHODS: A cohort of patients seen at the Mayo Clinic with TAK diagnosed between 1984 and 2009 and a cohort of patients with GCA and UE arterial involvement diagnosed between 1999 and 2008 were studied. RESULTS: The TAK cohort consisted of 125 patients (91% female); the mean age (±SD) at diagnosis was 30.9 (±10) years. The cohort of patients with GCA and UE involvement comprised of 120 patients (80% female); the mean age (±SD) at diagnosis was 67.8 (±7.5) years. The mean time from onset of symptoms to diagnosis was significantly longer in TAK (3.2 years) than GCA (0.5 years), p < 0.001. UE claudication was reported in 40% with TAK and 53% with GCA, p = 0.04. UE blood pressure discrepancy was present in 65% with TAK versus 28% with GCA, p < 0.001. Involvement of the thoracic aorta, abdominal aorta, carotid arteries, innominate artery, mesenteric artery, and left renal artery was more frequently observed in TAK (p < 0.05). Among patients with luminal changes of the thoracic aorta, stenotic/occlusive lesions were predominant in TAK (81% compared to 0% in GCA), whereas aneurysmal disease was more common in GCA (100% compared with 19% in TAK, p < 0.001). CONCLUSION: Patients with GCA and UE involvement differ from patients with TAK in clinical and imaging characteristics. Aortic aneurysms were more common in GCA, while stenotic changes of the aorta were more common in TAK, suggesting different pathophysiologic mechanisms or vascular response to injury.