Elastase binding capacity of alpha 2-macroglobulin in plasma of patients with asthma or chronic obstructive pulmonary disease, without alpha 1-protease inhibitor deficiency.

The amidolytic activity of alpha 2-macroglobulin complexed with porcine pancreatic elastase (EC 3.4.21.11) was assayed using succinyl-trialanyl-p-nitroanilide. The levels of activity were compared in chronic obstructive pulmonary disease patients, asthma patients, and in healthy subjects with no record of lung disease. Levels of alpha 1-protease inhibitor were also determined and only those cases within the normal range for alpha 1-protease inhibitor were selected. Both the asthma cases and those with chronic obstructive pulmonary disease had levels of elastase-binding capacity related to alpha 2-macroglobulin which were significantly higher than the control groups.