An elastase-specific inhibitor from human bronchial mucus. Pathogenesis in lung emphysema.

Under physiological conditions human bronchial mucus contains an elastase-specific inhibitor which is quite different from hitherto known inhibitors: alpha 1-antitrypsin, HI-30, and BSI-TE. In bronchial mucus of 100 patients suffering from obstructive airway disease the amount of this inhibitor specific against elastase from both pancreas and polymorphonuclear neutrophilic leucocytes was measured. A group of 18 patients showed no inhibitor in their native mucus rather than free elastolytic activity. Another group of 82 patients had no elastolytic activity in their native mucus but free anti-elastolytic activity together with varying amounts of elastase-specific inhibitor bound to proteases. In a total of 20 cases from both groups the inhibitor was not detectable, neither in a free nor in a complexed form. Presuming that there is no hereditary deficiency involved, a strong importance of inactivating reactions such as oxidation is concluded.