Although neutrophil elastase is implicated in the pathophysiology of emphysema, our results highlight a potentially important role for proteinase 3 because of its greater concentration in azurophil granules, its reduced association rate constant with all α-1-antitrypsin variants studied here, its greater diffusion distance, time spent uninhibited following degranulation, and its greater propensity to partition to α-2-macroglobulin where it retains proteolytic activity.
Raised concentrations of serum alpha 2-macroglobulin were not due to emphysema: 86 patients with emphysema, of PI type M, and the normal control subjects had similar average concentrations of alpha 2-macroglobulin.