AAT may be elevated into normal range in heterozygous-deficient patients during concurrent infection, pregnancy, estrogen therapy, steroid therapy, cancer, and during postoperative periods. Homozygous-deficient patients will not show such elevation. Normal AAT levels may occur in patients with liver disease who are heterozygotes. In normals, pregnancy and contraceptive medication may elevate levels. Levels are normally low at birth but rise soon thereafter.
Genotyping tests for the two most common mutations, S and Z. Rare alleles, null or otherwise, are not detected by this assay.
α1-antitrypsin therapy may alter the patient phenotype.
American Thoracic Society/European Respiratory Society statement: Standards for the diagnosis and management of individuals with alpha-1 antitrypsin deficiency. Am J Resp Crit Care Med. 2003 Oct 1; 168(7):818-900. PubMed 14522813
Buist AS. Alpha 1-antitrypsin deficiency in lung and liver disease. Hosp Pract (Off Ed). 1989 May 15; 24(5):51-59. (review). PubMed 2497126
de Serres FJ. Worldwide racial and ethnic distribution of alpha1-antitrypsin deficiency: summary of an analysis of published genetic epidemiologic surveys. Chest. 2002 Nov; 122(5):1818-1829. PubMed 12426287
Pierce JA. Antitrypsin and Emphysema. Perspective and Prospects. JAMA. 1988 May 20; 259(19):2890-2895. (review). PubMed 33285040