Occurrence of alpha-1-antitrypsin deficiency in 155 patients with alcoholic liver disease.

Liver biopsies from 155 patients with alcoholic liver disease were examined for periodic-acid-Schiff-positive, diastase-resistant (PAS-DR) intracytoplasmic globules in hepatocytes. Seven patients had these PAS-DR globules: each was a heterozygote for a deficiency allele of alpha-1-antitrypsin (AAT), or alpha-1-protease inhibitor, with the PAS-DR globules distributed in a pattern characteristic of this deficiency. One further patient with normal AAT had a few intracytoplasmic PAS-DR globules in occasional hepatocytes. The prevalence of AAT heterozygotes in this series did not differ from that in the reference population. The seven heterozygotes included five of PI (protease inhibitor) type MZ, one of PI type SZ, and one heterozygous for a rare deficiency allele, PI type MMmalton. The M and Mmalton alleles may be difficult to distinguish because they have similar mobilities with isoelectric focusing technics. Therefore, if PAS-DR inclusions are found in the liver of a patient with an apparently normal phenotype, the presence of a defective M variant allele, such as Mmalton, should be considered.