Serum α1-Antitrypsin Variants

The prevalence of serum α1-antitrypsin variants determined by an acid starch gel electrophoresis and crossed antigen-antibody electrophoresis was 11.6 per cent in 500 subjects visiting a multiphasic screening clinic in Monroe County, New York. The MZ type occurred in 3.6 per cent of the population. This subgroup had the lowest values of antitrypsin activity and, therefore, might be expected to be at a greater risk of developing lung disease. Analysis of α1-antitrypsin by electroimmunodiffusion separated all the MZ variants from 87.4 per cent of the total population study. Trypsin inhibitory capacity separated these MZ variants from only 21 per cent of this population. Although electroimmunodiffusion may be useful as a screening method, exact α1-antitrypsin typing requires acid starch gel electrophoresis and crossed antigen-antibody electrophoresis. When compared to normal subjects from the same population, persons with α1-antitrypsin variants had no evidence of obstructive lung disease by clinical spirome...