Extracellular proteinases of known macrophage origin have been difficult to identify at high levels in lung secretions from subjects with COPD and/or emphysema.

• 在COPD和肺气肿患者的高浓度的肺部分泌物中，我们很难确认究竟哪些是已知巨噬细胞源性的细胞外蛋白酶。