Alpha-1 antitrypsin replacement (augmentation therapy)

Purified human alpha-1 antitrypsin given by vein to people with severe deficiency and emphysema, to slow lung damage.

Updated Nov 1, 2026

What they are

Alpha-1 antitrypsin deficiency is an inherited condition in which the liver makes too little working alpha-1 antitrypsin, or makes a misfolded form that stays in the liver. The lungs are left exposed to neutrophil elastase, and emphysema develops early, especially in smokers. Augmentation therapy raises the blood level of the protein by regular intravenous infusions of purified human alpha-1 antitrypsin. It is lifelong and is meant to slow lung damage in people who already have emphysema; it does not treat the liver disease.

Mechanism of action

Alpha-1 antitrypsin is a serpin (serine protease inhibitor). Its main target is neutrophil elastase, an enzyme that white blood cells release to fight infection and that can digest the elastin of the alveolar walls. The protein traps the enzyme and inactivates it. Infused protein restores this protective shield in the lung.

Target: Neutrophil elastase, the protease that alpha-1 antitrypsin normally restrains in the lung

Drugs in this class

Alpha-1 proteinase inhibitor (human)Purified human alpha-1 antitrypsin given by vein, for life, to slow emphysema in severe alpha-1 antitrypsin deficiency.Neutrophil elastase

Others in the class

Stopping smoking is the most important measure in deficiency
Lung transplant in end-stage emphysema; liver transplant in severe cirrhosis

Test yourself

Think of the answer, then tap the question to see it.

Which enzyme does alpha-1 antitrypsin restrain in the lung?

Neutrophil elastase.

By which route is augmentation therapy given?

Intravenous infusion.

Does augmentation therapy treat the liver disease of alpha-1 antitrypsin deficiency?

No. It is aimed at slowing lung damage in emphysema.

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