Genetic vs. Quantitative Analysis of Serum Alpha1-Antitrypsin

In a study of the potential usefulness of quantitative methods for identifying heterozygous serum alpha1-antitrypsin genetic types that may be associated with chronic pulmonary disease, wide ranges of serum alph1-antitrypsin function and concentration were found in series of samples of protease inhibitor (Pi) types MM, MS and MZ samples. Ranges were wider in a group of 99 patients with obstructive pulmonary disease than in 106 normal adults, and demonstrated a greater overlap of types MS and MZ with type MM. Measurement of alpha1-antitrypsin function or concentration cannot be expected to detect Pi types MZ or MS reliably; quantitative screening methods must be accompanied by Pi typing analysis.