Increase in macrophage elastase (MMP-12) in lungs from patients with chronic obstructive pulmonary disease

Objective and design: Chronic obstructive pulmonary disease (COPD) is characterized by an inflammatory process and airway remodeling involving matrix metalloproteinases (MMPs). Thus, we analyzed the expression and release of MMP-12 (macrophage metalloelastase) in bronchoalveolar lavage (BAL) and lung tissue from COPD patients and control subjects. Methods: Immunocytochemistry and immunochemistry were performed to analyze the expression of MMP-12 in BAL cells and bronchial biopsies. Western blotting was used for the evaluation of MMP-12 in BAL fluids. Results: The number of MMP-12 expressing macrophages together with the staining intensity was higher in BAL samples from COPD patients than in controls subjects. Similar results were noted in bronchial biopsies with higher MMP-12 expression in COPD subjects than in controls. Enhanced MMP-12 level was also observed in BAL fluids from patient with COPD in comparison to control subjects. Conclusion: This study demonstrated that COPD patients produce greater quantities of MMP-12 than controls, which may be a critical step in the pathogenesis of COPD and emphysema.