EDNRA and idiopathic pulmonary arterial hypertension: Although some of these antibodies are not specific for SSc being detectable also in patients with other vascular diseases (i.e., idiopathic pulmonary arterial hypertension), Riemekasten et al. reported that higher levels of anti-AT1R and anti-ETAR autoantibodies were associated with severe SSc vascular manifestations, including digital ulcers, PAH and renal crisis [53].