Treatment of Early Systemic Sclerosis by Bosentan

Systemic sclerosis (SSc) is characterised by obliterative vasculopathy and extensive fibrosis. The accumulation of extracellular components in the extracellular matrix is mostly due to increased activity og tissue fibroblasts. The proliferation and hyperactivity of the fibroblasts may be caused by enhanced production of several cytokins, among them endothelin-1.The activity of endothelin-1 has been shown to be increased both in the circulation and within skin lesions. Endothelin-1 has several distinct properties, among them profibrotic activity, inflammatory and vasoconstriction.Thus, the actions induced by endothelin-1 may be a potensial target for the therapy of SSc.

Thirty patients with early SSc, that is of less than 12 months duration will be offered six months of treatment with the oral dual endothelin-1 antagonist bosentan. Assessment of disease progression will be performed at 3, 6, 9. 12 and 24 months using clinical, histological and immunohistochemical methods.