Human leucocyte elastase and serum alpha 1-antitrypsin.

Human leucocyte elastase concentration and its major circulating inhibitor, the alpha 1-antitrypsin, were compared in blood samples taken from 17 healthy male donors. Leucocyte elastase concentration was linearly correlated to the serum antitrypsin activity determined by its phenotypic constitution. Thus it seems that cellular elastase and its circulating inhibitor activities are closely coregulated. This might be mediated by the leucocyte elastase receptors which internalize free elastase possibly suppressing synthesis of the enzyme.