alpha-1 antitrypsin deficiency

Your lungs constantly face tiny demolition crews — enzymes that break down old or damaged proteins. Normally a protective guard called alpha-1 antitrypsin keeps those enzymes in check. In this inherited deficiency, the guard is scarce or defective, so the demolition runs unchecked and slowly chews away healthy lung tissue.

Alpha-1 antitrypsin deficiency is a genetic disorder in which the liver produces too little (or abnormal) alpha-1 antitrypsin, a protein that inhibits neutrophil elastase. Without enough of this inhibitor, elastase destroys the elastic walls of the alveoli, causing early-onset emphysema — often in the lower lungs and at a younger age than smoking-related COPD, especially in people who also smoke. Because the abnormal protein can build up in the liver, some patients develop liver disease too.

It should be suspected when emphysema appears before about age 45, in a non-smoker or light smoker, with a family history, or in basal (lower-lung) distribution. Diagnosis is by a blood level and genetic testing. Avoiding smoking is paramount; for selected patients, intravenous augmentation therapy with purified alpha-1 antitrypsin may slow lung-function decline.