Alpha-1-antitrypsin

What is alpha-1-antitrypsin?

Alpha-1-antitrypsin is a protein, produced by the liver, that enters the blood stream. Its main role is to protect the lungs from destruction by other proteins called enzymes.

Enzymes are found in all parts of the body and are needed for digestion to ensure that chemical reactions in the body take place normally. Enzymes are also involved in areas of inflammation and tissue injury where they occur as a result of cell damage.

How does A1AD occur?

A1AD is present when there is less than the normal amount of this protein in the blood. It becomes important only when the concentration in the blood is less than 20% to 30% of what we would normally expect. When alpha-1-antitrypsin levels get this low, the lung is poorly protected from destructive enzymes and loss of lung tissue occurs. This leads to emphysema (for more information on emphysema please see our leaflet on COPD).

Can I be treated for A1AD?

There is no specific treatment for it as yet.

Possible future treatments?

The current approach to A1AD is that, if it were possible to ‘top-up’ the body with protein, the progression of emphysema might be halted. Progress has been made to make ‘artificial’ alpha-1-antitrypsin through genetic synthesis. This is an extremely expensive process and only tiny amounts of the protein can be made.

A new approach?

Recently, a new approach was taken to the problem of manufacturing alpha-1-antitrypsin. Sheep were ‘tampered’ with genetically so that they would yield human alpha-1-antitrypsin, which is produced in their milk. Theoretically the alpha-1-antitrypsin can then be isolated for human use cheaply and in large amounts.

In this country the process of replacing alpha-1-antitrypsin is still very much in the experimental stage as the treatment has not yet been proven to be effective anywhere else in the world.

However, a study in the West Midlands is about to start which will try to determine whether ‘top-up’ therapy works.

In the United States they have already started to use ‘top-up’ therapy. However, there has been no proper study to gauge the success of this approach.