Sputum matrix metalloproteinase-9: Tissue inhibitor of metalloproteinase-1 ratio in acute asthma

Abstract Background: The ratio of matrix metalloproteinase-9 (MMP-9) and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1) may be a marker of the balance between airway tissue destruction and repair. TIMP-1 may potentially contribute to the pathogenesis of increased submucosal extracellular matrix deposition in asthma. Objective: Our purpose was to assess the variation in sputum MMP-9 and TIMP-1 during acute asthma. Methods: We evaluated the MMP-9 and TIMP-1 balance in sputa of 16 asthmatic patients admitted with spontaneous exacerbation, conducting measurement before (day 1) and after methylprednisolone infusion therapy (days 2, 3, 5, and 7), and on remission days. Results: Peak expiratory flow and eosinophilic cationic protein levels were significantly ( P P P P Conclusions: An imbalance between MMP-9 and TIMP-1 was present in acute asthma, with an excess of MMP-9 resulting in a high ratio of MMP-9/TIMP-1 before treatment, and over time with glucocorticosteroid the TIMP-1 levels rose, dropping the ratio of MMP-9/TIMP-1. It was suggested that overproduction of MMP-9 and TIMP-1 after asthma exacerbation might contribute significantly to airway tissue remodeling and that TIMP-1 production in acute asthma might not be suppressed by glucocorticosteroid. (J Allergy Clin Immunol 2000;105:900-905.)