Alpha1-antitrypsin Quick Facts

  • Synthesis: Liver, monocytes
  • Molecular mass: 53 000 D
  • Half-Life: 5 days
  • Plasma concentration: 1 – 1.3g/l
  • Normal range activity: 100%

Alpha1-antitrypsin Biochemistry

Alpha1-antitrypsin is mainly responsible for the inhibition of the activity of PMN-elastase in plasma. About 90% of the elastase in plasma is inhibited by α1-antitrypsin. Although it also inhibits various other serine proteases, as e.g. thrombin, factor XIa, trypsin and activated protein C (APC), α1-antitrypsin is of no significance in the coagulation system. It protects tissues from enzymes of inflammatory cells, especially neutrophil elastase. In the absence of alpha-1 antitrypsin (such as in alpha-1 antitrypsin deficiency), neutrophil elastase is free to break down elastin, which contributes to the elasticity of the lungs, resulting in respiratory complications such as emphysema, or COPD (chronic obstructive pulmonary disease) in adults and cirrhosis in adults or children. α1-Proteinase inhibitor, alpha-1 proteinase inhibitor (A1PI), α1-PI

Clinical Aspects of α1-antitrypsin

Reduced concentrations are observed in subjects with sepsis or multi-organ failure as well as in some genetic lung and liver diseases. As an acute phase protein, increased concentrations of α1-antitrypsin can be determined is some situations. Inherited deficiency may cause liver disease and lung emphysema at an early age.

Clinical or Research use of α1-antitrypsin

  • Control of sepsis and multi-organ failure
  • Monitoring of the elastase-inhibiting potential
  • Screening of newborns for α1-antitrypsin deficiency

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