α₁-Antitrypsin

Test ID:

702765

CPT code:

82103

Synonyms:

Acute Phase Proteins
Alpha1-Protease Inhibitor

Clinical Use:

Detection of hereditary decreases in the production of α1-antitrypsin (α1AT). Decreased or nearly absent levels of α1AT can be a factor in chronic obstructive lung disease and liver disease. An increased prevalence of non-MM phenotypes is found with cryptogenic cirrhosis and with CAH. Cirrhosis in a child should raise consideration of α1AT deficiency or Wilson’s disease. Diagnosis of inflammatory states, if elevated (eg, rheumatoid arthritis, bacterial infection, vasculitis, neoplasia).

Test Information:

Should be run when α1-globulin in serum protein electrophoresis is low or when two bands are seen in the α1-region. Heterozygous patients exhibit AAT levels which are commonly about 60% of normal. Homozygous recessive α1AT patients exhibit levels at about 10% of normal. Phenotyping is desirable on patients with low values and on all patients being worked up for AAT-deficient liver disease. Most pathologic is homozygous state ZZ. An M null genotype will have phenotype as MM but low serum level. AAT is one of the alpha-globulins, which together are called “acute phase reactants.” These rise rapidly, but nonspecifically, in response to inflammatory insults.