Differences in elastase-binding activity of α1-protease inhibitor and α2-macroglobulin for asthma patients and control subjects with various α1protease inhibitor phenotypes

Abstract

Forty-two adult patients with asthma and 30 control subjects were investigated for elastase-binding capacities of α1protease inhibitor and α2-macroglobulin in plasma. The binding activities of α1protease inhibitor and α2-macroglobulin in asthmatic patients with the M phenotype for the α1-protease inhibitor differed in their relationship to the values in control subjects with the same phenotype [less α1-Prortease inhibitor for asthmatics (35.1 ± 1.8) than for controls (42.9 ± 2.0 kU/L) (P <0.001); more α2-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 α1-protease inhibitor had lower activities of both α1protease inhibitor [22.1 ± 0.1 vs 42.9 ± 2.0 kU/L (P <0.001)] and α2-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.