A deficiency of a protein produced in the liver that blocks the destructive effects of certain enzymes. The condition may lead to emphysema and liver disease .
Causes, incidence, and risk factors
Alpha-1 antitrypsin deficiency results from a genetic defect. The mechanism that causes associated liver disease and emphysema in some people with this deficiency is not known, however some evidence suggests that it may be related to inflammation. Approximately 75% of adults with severe deficiency will develop emphysema, which often begins before 40 years of age. Smoking can increase risk.
Signs and tests
Physical examination may reveal a barrel-shaped chest. Listening to the chest with a stethoscope ( auscultation ) may reveal wheezing , crackles, and/or decreased breath sounds. The following tests may also help diagnosis:
arterial blood gases serum alpha-1 antitrypsin level
chest X-raypulmonary function test
Treatment
Replacement (or "augmentation") therapy with the missing AAT protein is available, however, it is not known how effective this is once disease has developed or which people would benefit most. Certainly, smoking avoidance or cessation is crucial. Other treatments include bronchodilators and prompt antibiotics for upper respiratory tract infections.
Expectations (prognosis)
Some people with this deficiency will not develop liver or lung disease . Emphysema and cirrhosis , however, are both progressive diseases which can kill.
Prevention
There is no known prevention for this genetic defect.