Heterozygous alpha 1-antitrypsin deficiency and cirrhosis in adults, a fortuitous association.

Pi (protease inhibitor) genotype was determined in 394 healthy blood-donors, 132 adult patients with alcoholic cirrhosis, and 37 adult patients with cryptogenic cirrhosis. The frequency of the heterozygous genotype with a single allele Pi Z (heterozygous alpha 1-antitrypsin deficiency) was not different in blood-donors and in patients with cirrhosis. This finding suggests that the association of this heterozygous genotype with cirrhosis is not causal but fortuitous and that this heterozygous genotype does not increase susceptibility to cirrhosis due to other causes, in particular alcoholism.