Alpha-1-Antitrypsin Deficiency   


Alpha-1-antitrypsin (A1AT) is a protein produced by the liver. A1AT deficiency is a genetic disease. It is due to a mutation of the gene controlling the production of A1AT. When the mutation is present, A1AT is kept back in the liver resulting in a low level of A1AT in the blood. Thus, it cannot properly assume its role of antiprotease. In healthy persons, A1AT helps protecting the organs against the attack of enzymes released by certain cells in case of an inflammation (for example an infection). In affected persons, the enzymes are not attenuated and mainly attack the lungs and destroy them progressively.

This results in emphysema (presence of air bubbles in the tissues), which brings about shortness of breath, cough, wheezing respiration and pulmonary infections. These symptoms often occur at adult age and are aggravated by tobacco.

In affected persons, the mutated A1AT accumulates in the liver and results in an inflammation (hepatitis). When this recurs, scars develop in the liver (cirrhosis), which prevents it from working properly. The symptoms are variable and some patients may be asymptomatic, but one of the manifestations of the disease is jaundice that may occur at birth or later. In general, this disease can be diagnosed by taking a simple blood sample to measure the quantity of A1AT in the blood. Other examinations can be carried out to describe the type of deficiency more specifically and to evaluate the status of the liver: abdominal ultrasonography, blood tests and a liver biopsy.

Bronchodilators and corticoids are used for the treatment of the pulmonary symptoms. Moreover, since the pulmonary symptoms are strongly aggravated by tobacco, it is strongly recommended to the patient and his environment not to smoke. It is also recommended to the patients to get vaccinations against the bacteria and the viruses likely to damage the lungs and the liver (influenza, pneumococcus, hepatitis A and B). In very severe cases of A1AT deficiency, a liver or lung transplant may be necessary.

Dr. Laura Semeraro