Uncovering the New Biology of Giant Cell Arteritis to Guide Therapeutic Strategies.

Giant cell arteritis (GCA) is a form of large vessel vasculitis that primarily affects older adults and forms granulomatous inflammation in the aorta and its major branches. Recent advances in immunology and multi-omics technologies have elucidated several key mechanisms involved in the pathogenesis of GCA, including immune checkpoint dysregulation, clonal hematopoiesis, and age-associated immune dysfunction. From the perspective of immune cell subsets, a diverse range of immune cells-including tissue-resident memory T cells, stem-like T cells, macrophage subsets, B cells, and myofibroblasts-play distinct roles in sustaining vascular inflammation and tissue remodeling. This review summarizes the latest immunopathological and omics-based insights into GCA, proposes potential therapeutic targets, and discusses future directions for precision medicine aimed at achieving sustained remission.