ABSTRACT
The aim of this study was to determine the serum levels of endothelin-1 [EN-1] as a marker of endothelial cell activation in patients with systemic sclerosis [SSc] and to investigate its relationship to specific organs involvement. Thirty two female patients diagnosed as SSc were included in this study; all of them met the criteria proposed by the ACR. Serum EN-1 was detected by enzyme linked immunosorbent assay [ELISA] for the patients and 20 matched healthy subjects as a control group. Thorough clinical assessment was performed; high resolution computed tomography [HRCT] scan and scoring was done for patients with pulmonary fibrosis; doppler echocardiography was done to assess pulmonary artery pressure. In this study; there was highly significant increase in the mean titre of EN-1 in SSc patients than in control group [<0.001] and significant increase in diffuse than limited SSc [P<0.05]. Significantly higher levels of Serum EN-1 were found in SSc patients complaining from pulmonary fibrosis, pulmonary and systemic arterial hypertension [P<0.001], higher in patients complaining from sclerodactyly, digital ulcers, cardiac and renal affection and in patients positive either for Anti-TOPO-I antibodies or ACA [P<0.05]. Also, there were significant positive correlation between mean pulmonary artery pressure, mean systemic arterial pressure, levels of serum creatinine, serum urea, 24 hours proteinuria, titre of ANA, anti- TOPO-I antibodies, ACA and HRCT scores with serum levels of EN-1 in SSc patients. Also, there was a significant negative correlation with creatinine clearance. Enothelin-1 through endothelial cell activation has a pathogenic role in SSc that help in evaluation of the clinical severity of scleroderma lung disease, systemic hypertension, cardiac and renal affection. EN-1 may also represent a promising serological parameter for therapeutic consideration; use of endothelin receptor antagonist may be a strategy for reaching clinical improvement