Comparison of fibrinolytic and anti-fibronolytic activity in patients with idiopathic interstitial pneumonia with predominant fibrosis or inflammation

Abstract

Objective To detect and compare the levels of urokinase plasminogen activator (u-PA),tissue plasminogen activator (t-PA),and plasminogen activator inhibitor 1 (PAI-1) in the bronchoalveolar lavage fluid (BALF) and the plasma of patients with idiopathic interstitial pneumonia (IIP) with predominant fibrosis or inflammation.Methods BALF and plasma were derived from 144 patients with IIP including 102 cases of idiopathic pulmonary fibrosis (IPF) and 42 non-IPF cases of IIP (nIPF-IIP),and 26 controls.Results u-PA levels in BALF of patients with IPF [(0.20±0.01) μg/L] and nIPF-IIP [(0.22 ± 0.01) μg/L] were significantly decreased compared with controls [(0.27 ± 0.01) μg/L,P ＜0.01].PAI-1 levels in BALF of patients with IPF [(4.05±0.85) μg/L] and nIPF-IIP [(3.69 ± 0.88) μg/L] were significantly increased compared with controls [(1.11 ± 0.12) μg/L,P ＜0.05 or P ＜0.01.Both t-PA and PAI-1 levels in plasma were significantly elevated in patients with IIP (P ＜0.01).Conclusions There is depressed fibrinolytic or enhanced anti-fibronolytic activity in the lung of patients with IPF and nIPF-IIP,characterized by decreased u-PA and increased PAI-1.There is augmented anti-fibronolytic activity in plasma presented with elevated PAI-1 in patients with IPF and nIPF-IIP.Such decrease fibrinolysis in patients with IPF and nIPF-IIP,especially in IPF,maybe promote the development of pulmonary fibrosis.It is warranted to study the role of fibronolytic system composed mainly of u-PA and PAI 1 in pathogenesis of pulmonary fibrosis,correlation with the subtype of IIP or the degree of fibrosis. Key words: Idiopathic interstitial pneumonia; Pulmonary fibrosis; Fibrinolysis