LAUSR

Endothelin 1 (ET-1) is a potent vasoactive peptide hormone produced by endothelial cells, macrophages and vascular smooth muscle cells (VSMCs). Elevated ET-1 plasma levels have been reported in patients with ischaemic complications in giant-cell arteritis (GCA), a systemic vasculitis predominantly affecting large vessels and their branches.1 In temporal artery biopsy specimens, increased expression of ET-1 and the G protein-coupled vasoconstrictive endothelin receptor A (ETAR) has been found.2 ETAR activation induces focal adhesion kinase-mediated morphological changes and increased motility of VSMC potentially contributing to intimal hyperplasia and vascular occlusion in GCA.3 VSMC migration can be blocked by specific ETAR antagonists.3 Notably, disease-specific anti-G protein-coupled receptor autoantibody (aab) signatures have been found in different autoimmune diseases.4 5 Anti-ETAR aabs are increased and associated with pulmonary arteriolar occlusion and hypertension in systemic sclerosis.5 6 Anti-ETAR aabss induce vascular adhesion molecules, interleukin (IL)-8 and chemokine ligand CCL-18 productions and exhibit chemotactic activity by mediating neutrophil and T cell migration.5 6 To address …