DIFFERENCES IN ELASTASE-BINDING ACTIVITY OF ALPHA-1-PROTEASE INHIBITOR AND ALPHA-2-MACROGLOBULIN FOR ASTHMA PATIENTS AND CONTROL SUBJECTS WITH VARIOUS ALPHA-1-PROTEASE INHIBITOR PHENOTYPES

Forty-two adult patients with asthma and 30 control subjects were investigated for elastase-binding capacities of alpha1-protease inhibitor and alpha2-macroglobulin in plasma. The binding activities of alpha1-protease inhibitor and alpha2-macroglobulin in asthmatic patients with the M phenotype for the alpha1-protease inhibitor differed in their relationship to the values in control subjects with the same phenotype [less alpha1-protease inhibitor for asthmatics (35.1 +/- 1.8) than for controls (42.9 +/- 2.0 kU/L) (P <0.001); more alpha2-macroglobulin for asthmatics (6.9 +/- 0.3) than for control subjects (5.9 +/- 0.4 kU/L) (P <0.03)]. In contrast, the patients with a deficiency allele (S, V, or Z) for al-protease inhibitor had lower activities of both alpha1-protease inhibitor [22.1 +/- 0.1 vs 42.9 +/- 2.0 kU/L (P <0.001)] and alpha2-macroglobulin [4.6 +/- 0.6 vs 5.9 +/- 0.4 kU/L (P <0.001)] than did the control subjects with the M phenotypes. The relevance of the results to the pathogenesis of asthma is discussed.