Large-vessel vasculitis

Large-vessel vasculitis includes giant cell arteritis (GCA) and Takayasu’s arteritis (TAK). GCA affects patients aged over 50, mainly of white European ethnicity. GCA occurs together with polymyalgia rheumatica (PMR) more frequently than expected by chance. In both conditions, females are affected two to three times more often than males. GCA mainly involves large- and medium-sized arteries, particularly the branches of the proximal aorta including the temporal arteries. Vasculitic involvement results in the typical manifestations of GCA including temporal headache, jaw claudication, and visual loss. A systemic inflammatory response and a marked response to glucocorticoids is characteristic of GCA. GCA usually remits within 6 months to 2 years from disease onset. However, some patients have a chronic-relapsing course and may require longstanding treatment. Mortality is not increased, but there is significant morbidity mainly related to chronic glucocorticoid use and cranial ischaemic events, especially visual loss. The diagnosis of GCA rests on the characteristic clinical features and raised inflammatory markers, but temporal artery biopsy remains the gold standard to support the clinical suspicion. Imaging techniques are also used to demonstrate large-vessel involvement in GCA. Glucocorticoids are the mainstay of treatment for GCA, but other therapeutic approaches have been proposed and novel ones are being developed. TAK mainly involves the aorta and its main branches. Women are particularly affected with a female:male ratio of 9:1. In most patients, age of onset is between 20 and 30 years. Early manifestations of TAK are non-specific and include constitutional and musculoskeletal symptoms. Later on, vascular complications become manifest. Most patients develop vessel stenoses, particularly in the branches of the aortic artery, leading to manifestations of vascular hypoperfusion. Aneurysms occur in a minority of cases. There are no specific laboratory tests to diagnose TAK, although most patients have raised inflammatory markers, therefore, imaging techniques are required to secure the diagnosis. Glucocorticoids are the mainstay of treatment of TAK. However, many patients have an insufficient response to glucocorticoids alone, or relapse when they are tapered or discontinued. Immunosuppressive agents and, in refractory cases, biological drugs can often attain disease control and prevent vascular complications. Revascularization procedures are required in patients with severe established stenoses or occlusions.