Plasma endothelin-1 levels, pulmonary hypertension, and lung fibrosis in patients with systemic sclerosis.
OBJECTIVE
To investigate the behavior of circulating endothelin (ET)-1 concentrations in patients affected by systemic sclerosis, and to elucidate the possible relationships existing in this disease among plasma peptide levels, pulmonary hypertension, and lung fibrosis.


METHODS
Circulating ET-1 levels were determined by reverse-phase, high-pressure liquid chromatography followed by sensitive radioimmunoassay in 20 patients affected by systemic sclerosis (18 women and 2 men, mean age 48.1 +/- 13.7 years) with or without pulmonary hypertension as evaluated by Doppler echocardiography, or lung fibrosis as measured by a score method based on lung examination by high-resolution computed tomography (HRCT). A group of 18 normal volunteers served as controls (15 women and 3 men, mean age 45.0 +/- 10.1 years).


RESULTS
Plasma ET-1 levels were significantly higher (P < 0.001) in patients with systemic sclerosis (1.72 +/- 0.28 pg/mL) than in control subjects (0.63 +/- 0.06 pg/mL). Pulmonary artery systolic hypertension was detected in 10 patients (50%) with systemic sclerosis (56.2 +/- 18.0 mm Hg, range 37 to 97) versus none of the control subjects (30.2 +/- 2.2 mm Hg, P < 0.0001). Lung fibrosis was present in 12 patients (60%), with an HRCT overall score of 9.0 +/- 4.6. There were no significant differences in plasma ET-1 levels between patients with pulmonary hypertension (1.58 +/- 0.20 pg/mL) or without it (1.76 +/- 0.39 pg/mL, P = 0.188, not significant [NS]); or between patients with lung fibrosis (1.65 +/- 0.14 pg/mL) or without fibrosis (1.78 +/- 0.37 pg/mL, P = 0.290, NS). In particular, 6 patients had neither pulmonary hypertension nor lung fibrosis. In these patients, plasma ET-1 levels were similar compared with the others (1.85 +/- 0.49 versus 1.66 +/- 0.13, respectively; P = 0.180, NS). No correlations were observed between ET-1 levels and either pulmonary pressure levels or HRCT overall scores.


CONCLUSIONS
The use of a sensitive assay, highly selective for ET-1, showed higher levels of circulating peptide in patients affected by systemic sclerosis than in control subjects. Neither pulmonary hypertension nor lung fibrosis was accompanied by a further rise in plasma ET-1 concentrations.
Morelli
S
S
University of Rome La Sapienza, Institute of I Clinica Medica-Andrea Cesalpino Foundation, Italy.
Ferri
C
C
Polettini
E
E
Bellini
C
C
Gualdi
G F
GF
Pittoni
V
V
Valesini
G
G
Santucci
A
A
D000328:Adult; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D004452:Echocardiography; D016232:Endothelins / Q000097:blood*; D005260:Female; D005355:Fibrosis / Q000209:etiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology*; D016014:Linear Models; D008168:Lung / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012595:Scleroderma, Systemic / Q000097:blood* / Q000150:complications*
D016232:Endothelins