Alpha-1 antitrypsin

Alpha-1 antitrypsin is a member of the serine protease inhibitor family of plasma proteins. Alpha-1 antitrypsin has a wide spectrum of antiprotease activity, however, its important physiological role is the inhibition of neutrophil elastase. Alpha-1 antitrypsin is primarily synthesised in the liver and normally constitutes about 90% of the circulating blood alpha-1 globulin.

Reference range is 1.4-3.4 g/L (note reference ranges may vary between laboratories).

Note that levels of alpha1-antitrypsin are increased in all people in trauma, acute infections and pregnancy.