ALPHA-1-PROTEASE INHIBITOR IN BRONCHIAL-ASTHMA - PHENOTYPES AND BIOCHEMICAL CHARACTERISTICS

The prevalence of the different phenotypes of alpha-1-protease inhibitor (alpha-1PI) was investigated in a group of go asthmatic patients and compared with that of a control group of 240 individuals representing the general population. The M2M2 phenotype occurred more frequently in the asthmatic group (p = 0.015). Plasma samples of 51 of the asthmatic patients randomly selected from the different phenotype groups identified were studied for the absolute plasma values of alpha-1-PI and the inhibitory capacity of plasma for porcine pancreatic elastase, and compared with those from 21 nonasthmatic individuals of the M1M1 phenotype. Although the asthmatic patients had higher absolute alpha-1PI values (p = 0.04), the plasma elastase inhibitory capacity was markedly reduced compared with the nonasthmatic subjects (p = 0.01). The functional efficiency of alpha-1PI from asthmatic patients of the M1M1, M1M2, and M2M2 phenotypes was significantly decreased compared with that of the nonasthmatic M1M1 individuals. Functional deficiency of alpha-1PI may be important in the pathogenesis of the inflammatory process that characterizes bronchial asthma.