MMP expression and abnormal lung permeability are important determinants of outcome in IPF

• Published in: The European respiratory journal Vol. 33; no. 1; pp. 77 - 84
• Main Authors: McKeown, S, Richter, A. G, O'Kane, C, McAuley, D. F, Thickett, D. R
• Format: Journal Article
• Language: English
• Published: Leeds Eur Respiratory Soc 01.01.2009; Maney
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Bronchoalveolar Lavage; Capillary Permeability - physiology; Case-Control Studies; Cohort Studies; Female; Humans; Idiopathic Pulmonary Fibrosis - enzymology; Idiopathic Pulmonary Fibrosis - physiopathology; Idiopathic Pulmonary Fibrosis - therapy; Lung - metabolism; Lung - pathology; Lung - physiopathology; Male; Matrix Metalloproteinases, Secreted - metabolism; Medical sciences; Middle Aged; Pneumology; Respiratory system : syndromes and miscellaneous diseases; Tissue Inhibitor of Metalloproteinases - metabolism; Treatment Outcome; Vascular Endothelial Growth Factor A - metabolism; Lung disease; Prognosis; Enzyme; Respiratory disease; Determinant; Lung; Idiopathic pulmonary fibrosis; Idiopathic; Metalloendopeptidases; Permeability; Gene expression; Peptidases; Vascular endothelium growth factor; Pulmonary fibrosis; vascular endothelial growth factor; Hydrolases; Evolution; matrix metalloproteinase; Pneumology
• ISSN: 0903-1936; 1399-3003
• DOI: 10.1183/09031936.00060708

Matrix metalloproteinases (MMPs) degrade all of the extracellular matrix components of the intersititium and may play a role in abnormal alveolar permeability, which is a feature of idiopathic pulmonary fibrosis (IPF). The aims of the present study were to evaluate MMP protein levels in patients with IPF and determine any relationship to treatment and markers of permeability. In total, 20 patients with IPF and eight normal controls underwent bronchoalveolar lavage. MMP, tissue inhibitor of metalloproteinase, and vascular endothelial growth factor (VEGF) levels were related to clinical outcome and protein permeability index. MMP-3, -7, -8 and -9 were elevated in IPF lavage fluid and levels remained high despite treatment. Levels of MMP-3, -7, -8 and -9, VEGF and protein permeability index were higher in those who died early during follow-up. VEGF, and MMP-8 and -9 levels were higher in those with a rapidly declining lung function over 1 yr. Levels of MMP-3, -7, -8 and -9 correlated with an increased permeability index. Matrix metalloproteinase levels were elevated in idiopathic pulmonary fibrosis patients and were not modulated by current standard treatment. Matrix metalloproteinase production through an interaction with the known vascular permogen, vascular endothelial growth factor, was potentially associated with abnormal capillary permeability and may have potentiated the neo-angiogenesis seen in idiopathic pulmonary fibrosis. The changes were greatest in those who died or progressed during follow-up, suggesting that drugs targeting vascular endothelial growth factor or matrix metalloproteinase activity warrant assessment as novel therapy for idiopathic pulmonary fibrosis.