Takayasu's Arteritis Global Registry aims to bring a large group of patients from different parts of the world to analyse and compare the patients' demographic, clinical, laboratory, radiological and prognostic features with outcomes, approaches to diagnosis, assessment, management and therapeutic interventions in different centers. The present project provides for both a retrospective and a prospective longitudinal study. The study is designed as retrospective for patients already diagnosed with TAK and treated with available treatments. Also, the study is designed as prospective for patients diagnosed with TAK after the initiation of the Registry or the adhesion to the project. This is thought as a multicentre, international study addressed to all Centers that will want to contribute to the present project. The study is non-interventional: demographic, clinical and therapeutic data required over time are collected with the routine diagnostic, clinical and therapeutic procedures usually carried out for the optimal management of patients and according with good clinical practice.

Inclusion Criteria:

• Each patient must fullfill the ACR 1990 or ACR/EULAR 2021 criteria for Takayasu arteritis.
• Patients (or legally acceptable representatives of subjects enrolled) have to
• provide informed and free agreement to participate in the study and to disclose any medical event to the investigator. The parents or legally acceptable representative and the adolescent subject must be willing and able to comply with the study protocol requirements for the duration of the study
• freely sign written and dated informed consent after being duly informed of the nature, significance, and implications of the study;
• be informed that the patient enrolled may withdraw consent at any time without prejudice to future medical care.

Exclusion Criteria:

Patients must be excluded from the study when the following criteria are observed:

• The patient does not full-fill the ACR 1990 or ACR/EULAR 2021 criteria for Takayasu arteritis
• informed consent/assent is not provided and signed

Patients aged >18 years diagnosed with Takayasu arteritis according to ACR 1990 or ACR/EULAR 2021 criteria will be included