MMP8 and pulmonary emphysema: 24 MMP-8, also known as collagenase-2 or neutrophil collagenase, is involved in various lung diseases such as asthma, bronchiectasis, pulmonary emphysema, acute lung injury, and pulmonary TB.24,32,33 As shown in this study, the beneficial role of MMP-8 in risk stratification may be related to the fact that a higher MMP-8 level indicates greater disease burden and severity.