Patients with rheumatoid arthritis (RA) have been found to make autoantibodies toward the carbamylated form of A1AT in the synovial fluid. This suggests that A1AT may play an anti-inflammatory or tissue-protecting role outside the lungs. These antibodies are associated with a more severe disease course, can be observed years before disease onset, and may predict the development of RA in arthralgia patients. Consequently, carbamylated A1AT is currently being developed as an antigenic biomarker for RA. Nomenclature
The protein was initially named "antitrypsin" because of its ability to bind and irreversibly inactivate the enzyme trypsin in vitro covalently. Trypsin, a type of peptidase, is a digestive enzyme active in the duodenum and elsewhere. The term alpha-1 refers to the proteins behavior on protein electrophoresis. On electrophoresis, the protein component of the blood is separated by electric current. There are several clusters, the first being albumin, the second being the alpha, the third beta and the fourth gamma (immunoglobulins). The non-albumin proteins are referred to as globulins. The alpha region can be further divided into two sub-regions, termed "1" and "2". Alpha-1 antitrypsin is the main protein of the alpha-globulin 1 region. Another name used is alpha-1 proteinase inhibitor (α1-PI). Genetics
The gene is located on the long arm of chromosome 14 (14q32.1). Over 100 different variants of α1-antitrypsin have been described in various populations. North-Western Europeans are most at risk for carrying one of the most common mutant forms of A1AT, the Z mutation (Glu342Lys on M1A, rs28929474).
Páll A, Becs G, Erdei A, Sira L, Czifra A, Barna S, Kovács P, Páll D, Pfliegler G, Paragh G, Szabó Z (2014). "Pseudopheochromocytoma induced by anxiolytic withdrawal". European Journal of Medical Research. 19: 53. doi:10.1186/s40001-014-0053-9. PMC 4196012. PMID 25288254. External links
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