Alpha-1-antitrypsin in liver disease.
Low alpha-1-antitrypsin (AAT) levels are known to be associated with liver disease. As AAT is also synthesised in the liver, we investigated whether liver disease itself may result in low AAT levels. AAT was measured in plasma from 100 patients with various liver diseases including hepatitis, cirrhosis, jaundice and liver failure. Twenty-eight patients had increased AAT values (greater than 3.1 g/L), 70 had normal AAT values (between 1.5 and 3.1 g/L) and 2 had decreased AAT levels (less than 1.5 g/L). The 2 patients with low AAT levels were found to be of the PiMZ phenotype. There was no significant correlation between any of the standard 'liver function tests' and the AAT level. Our findings suggest that in liver disease AAT levels are usually normal or increased. Low levels are uncommon and the possibility of an abnormal AAT phenotype being associated with the liver disease should be examined.