Vasculitides

Despite the spatial closeness of blood vessels and inflammatory cells, blood vessel walls are infrequently targeted by inflammation. Giant cell arteritis (GCA) and Takayasu’s arteritis (TA) are characterized by inflammation directed against the vessel wall. GCA and TA display stringent tissue tropism and affect defined vascular territories in a preferential manner. GCA predominantly affects the second- to fifth-order aortic branches, often in the extracranial arteries of the head. The aorta itself may also be affected in GCA, albeit less often than other regions. In contrast, in TA, the aorta and its major branches are the prime disease targets.