Diagnostic and classification criteria of Takayasu arteritis.

Takayasu arteritis (TA) is a chronic large vessel vasculitis that affects aorta, its main branches and pulmonary arteries. The inflammatory process results in stenosis, occlusion, dilation or aneurysm formation in the arterial wall. TA has been described in different parts of the world and affects predominantly young individuals (<50 years of age). Patients with TA may present constitutional symptoms, vascular pain (e.g. carotidynia) and typical features such as limb claudication, decreased or absent peripheral pulses, vascular bruits, hypertension, and reduction or discrepancies in blood pressure between arms. A proper diagnosis of TA is an important issue since delays may result in significant morbidity. The definition of TA was included in the 1994 and 2012 Chapel Hill Consensus Conference and TA was categorized as a large vessel vasculitis. The first diagnostic criteria for TA were developed by Ishikawa in 1988 and modified by Sharma et al., in 1995. Two sets of classification criteria were developed for TA to include patients in epidemiologic studies and clinical trials: the 1990 ACR Classification Criteria for TA and the Classification Criteria for childhood TA proposed by the European League Against Rheumatism (EULAR), the Pediatric Rheumatology European Society (PRES) and by the Pediatric Rheumatology International Trials Organization (PRINTO) to be used for patients younger than 18 years. The Diagnostic and Classification Criteria in Vasculitis Study (DCVAS) is an international effort that is under way to develop a single classification system and a validated set of diagnostic criteria for systemic vasculitides using data-driven methods.