Figure 2.

Pathogenesis of giant cell arteritis. (a) Recruitment and stimulation of antigen-specific T cells by dendritic cells. Interferon-γ regulates the differentiation and function of macrophages. Macrophages in the adventitial layer supply interleukin-1 and interleukin-6, and in the media secrete metalloproteinases. (b) Platelet-derived growth factor and vascular endothelial growth factor are responsible for intimal hyperplasia, then favour lumen-occlusive arteritis. Reproduced with permission from Weyland et al. N Engl J Med 2003 Copyright © 2003 Massachusetts Medical Society [5].