Sputum matrix metalloproteinase-9 is associated with the degree of emphysema on computed tomography in COPD

Matrix-metalloproteinase (MMP)-9 has been implicated in the pathogenesis of COPD, although its link to disease severity is unclear. The

Sputum MMP-9 concentrations in COPD are directly associated with the extent of emphysema measured by CT and MMP-9 expression levels are inversely associated with DLco. These findings support a role for MMP-9 in the pathogenesis of COPD.