[Treatment of digital ulcers in systemtic sclerosis with endothelin-1 receptor antagonist (bosentan)]

Area of Science:

• Rheumatology
• Vascular Medicine
• Dermatology

Background:

• Recurrent digital ulcers (DU) cause significant pain and disability in systemic sclerosis (SSc).
• Standard vasodilator therapies often prove ineffective for managing DU in SSc patients.
• Endothelin-1 (ET-1) is implicated in SSc vascular dysfunction, leading to vasoconstriction and ischemia.

Purpose of the Study:

• To evaluate the efficacy of bosentan, an endothelin receptor antagonist, in preventing new digital ulcers in SSc patients.
• To assess the impact of bosentan on existing digital ulcers in patients with SSc.

Main Methods:

• Nine SSc patients (eight with PAH, one with refractory DU) received bosentan (62.5 mg bid for 4 weeks, then 125 mg bid for one year).
• Patients had pre-existing digital ulcers (3-4 per patient) at baseline.
• Occurrence of new DU and changes in existing DU were monitored throughout the treatment period.

Main Results:

• Seven out of nine patients showed no new digital ulcer development during the study.
• A 50% reduction in the size of existing digital ulcers was observed in treated patients.
• New digital ulcers occurred in only two patients, indicating a significant preventative effect.

Conclusions:

• Endothelin-1 plays a critical role in the pathogenesis of digital ulcers in systemic sclerosis.
• Bosentan, by inhibiting ET-1, demonstrates significant therapeutic potential in reducing the incidence and severity of digital ulcers in SSc.
• ET-1 inhibition represents a promising strategy for managing digital ulcer complications in SSc.