Immunohistological study endothelin-1 and endothelin-A and B receptors in two patients with scleroderma renal crisis.

Scleroderma renal crisis (SRC) developed in two patients with systemic sclerosis (SSc) and they died from respiratory failure. Findings on autopsy revealed congestion and oedema in both lungs and intimal thickening of the small renal arteries in both patients. Immunohistological investigations showed positive staining of anti-human endothelin (ET)-1 in the media of the small renal arteries and ET-B receptor in the medial smooth muscle of the small renal arteries. This observation suggests an important pathophysiological role of ET-1 in the development of SRC in some patients with SSc.