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 (E T-1) in patients affected by systemic sclerosis and to elucidate the r elationship between systemic and pulmonary plasma peptide and arterial pressure levels. Methods-Plasma ET-1 concentrations were determined i n 48 patients affected by systemic sclerosis (41 women, seven men; mea n age 47.2 (SD 5.5) years) with or without systemic or pulmonary hyper tension (or both). A group of 18 normal volunteers served 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 scl erosis (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 H g), and systemic hypertension alone (160.7 (5.9)/100.6 (3.2) mm Hg) wa s present in 11 patients. Both conditions were present in 12 patients, while 11 patients had systemic sclerosis without pulmonary or systemi c hypertension. There were no significant differences in plasma ET-1 l evels 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 pre ssures (n = 11) had plasma ET-1 concentrations identical to those foun d in patients (n = 12) with both pulmonary and systemic hypertension ( 1.70 (0.15) v 1.64 (0.35) pg/ml, respectively). No correlations were o bserved between plasma ET-1 and either pulmonary or systemic pressures . Conclusion-Systemic sclerosis is characterised by increased plasma E T-1 levels, but neither pulmonary nor systemic hypertension are accomp anied by further increase in plasma peptide levels.