ENDOTHELIN-1 IN IDIOPATHIC PULMONARY FIBROSIS

Aims-To evaluate whether endothelin-1 is involved in the pathology of idiopathic pulmonary fibrosis (IPF). Methods-Plasma endothelin-1 conce ntrations were evaluated in 37 patients with IPF and 27 normal control s by radioimmunoassay. In addition, expression of endothelin-1 in lung tissue was evaluated in biopsy specimens obtained from four patients with IPF. Three biopsy specimens of normal lung were used as controls. Endothelin-1 immunoreactivity was detected using immunohistochemistry . Results-Elevated endothelin-1 plasma concentrations were found in pa tients with IPF compared with controls and a positive correlation was found with duration of disease. No significant difference was observed between treated and untreated patients with IPF. Increased endothelin -1 immunoreactivity was found in lungs of three of four patients with IPF. Endothelin-1 positive cells consisted mainly of small vessel endo thelial cells. Some scattered macrophages were also positive. Conclusi ons-Elevated plasma concentrations and expression of endothelin-1 in l ung tissue are suggestive of increased production of endothelin-1 in a t least a proportion of patients with IPF. Consequently, endothelin-1 activity could play a role in the fibrogenic process of the disease.