PLASMA ENDOTHELIN-1 LEVELS IN PATIENTS WITH SYSTEMIC-SCLEROSIS - INFLUENCE OF PULMONARY OR SYSTEMIC ARTERIAL-HYPERTENSION

Objectives - To investigate the behaviour of circulating endothelin-1 (ET-1) in patients affected by systemic sclerosis and to elucidate the relationship between systemic and pulmonary plasma peptide and arterial pressure levels. Methods - Plasma ET-1 concentrations were determined in 48 patients affected by systemic sclerosis (41 women, seven men; mean age 47.2 (SD 5.5) years) with or without systemic or pulmonary hypertension (or both). A group of 18 normal volunteers sewed as controls (15 women, three men; mean age 45.0 (10.1) years). Results - Plasma ET-1 levels were significantly greater in patients affected by systemic sclerosis (1.65 (0.29) pg/ml) than in controls (0.63 (0.19) pg/ml) (p < 0.0001). Pulmonary artery systolic hypertension alone was present in 14 patients with systemic sclerosis (50.5 (8.49) mm Hg, range 37-67 mm Hg), and systemic hypertension alone (160.7 (5.9)/100 6 (3.2) mm Hg) was present in 11 patients. Both conditions were present in 12 patients, while 11 patients had systemic sclerosis without pulmonary or systemic hypertension. There were no significant differences in plasma ET-1 levels between patients with pulmonary hypertension alone (1.62 (0.21) pg/ml) and those with systemic hypertension alone (1.65 (0.43) pg/ml). In particular, patients with normal pulmonary artery and systemic pressures (n=11) had plasma ET-1 concentrations identical to those found in patients (n = 12) with both pulmonary and systemic tension (1.70 (0.15) v 1.64 (0.35) pg/ml, respectively). No correlations were observed between plasma ET-1 and either pulmonary or systemic pressures. Conclusion - Systemic sclerosis is characterised by increased plasma ET-1 levels, but neither pulmonary nor systemic hypertension are accompanied by further increase in plasma peptide levels.