Serum protein changes associated with alpha1-antitrypsin deficiency.

Using a radial immunodiffusion technique, the concentrations of eight serum proteins have been measured in sera from 60 chest clinic patients previously shown to have abnormally low alpha1-antitrypsin levels, and in 60 age and sex matched control sera. Of the proteins, only alpha2-macroglobulin showed a highly significant increase in the alpha1-antitrypsin deficient group. The findings confirm a previously reported association between alpha1-antitrypsin deficiency and increased alpha2-macroglobulin, and lend support to the suggestion that the rise in alpha2-macroglobulin is a specific compensatory response.