The contribution of α1-antitrypsin to the total antitrypsin activity of human serum. a study of two phenotype pi oo individuals

Comparison of the levels of α₁AT, α₂-M, inter α-AT, C₁ inactivator and antiplasmin and global antitrypsin activity in a group of normal phenotype PI MM individuals, a group of normal individuals with phenotypes with intermediate α₁AT activities and two α₂-AT-deficient persons show that α₁AT contributes more than 90% of the total antitrypsin activity of normal plasma.AT III and fast reacting antiplasmin are shown to contribute to the remaining activity. It can be assumed that due to test conditions the antitrypsin activity of α₂-M is not assessed. C₁ inactivator and inter α₁-AT do not contribute to a perceptible extent to the overall antitrypsin activity estimated according to the method of Eriksson (Eriksson, S. (1965) Acta Med. Scand. 177, 1).