ROLE OF THROMBIN IN PULMONARY FIBROSIS

Pulmonary fibrosis commonly develops in systemic sclerosis. We assesse d the role of thrombin in promoting fibroblast proliferation in the lu ngs in this disorder. Bronchoalveolar lavage fluid (BALF) thrombin con centrations were higher in ten patients with systemic sclerosis than i n 12 healthy controls (14.6 vs 3.6 nmol/L, p<0.02), but values in pati ents with cryptogenic fibrosing alveolitis (n=10) or sarcoidosis (n=10 ) were not increased. BALF from all patients induced fibroblast prolif eration. This proliferation was attenuated by thrombin inhibitors for BALF from systemic sclerosis patients only. We suggest thrombin contri butes to lung fibroblast proliferation in this disorder.