Definition of Alpha-1 antitrypsin deficiency

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Alpha-1 antitrypsin deficiency: An inherited disorder that results in low or no production of a protein called alpha-1 antitrypsin. This deficiency leads to damage of various organs, principally the lungs and liver. Symptoms can surface at a very early age or in adulthood and relate to the lungs (with shortness of breath) or the liver. There are several options for treatment of the lung disease, including replacement of the missing protein. Treatment of the liver disease is a well-timed liver transplant.

Alpha-1 antitrypsin is made in the liver which releases it into the bloodstream. When the lungs do not have enough alpha-1 antitrypsin, the enzyme neutrophil elastase is free to destroy lung tissue. As a result, the lungs lose some of their elasticity and their ability to expand and contract. This leads to emphysema and sometimes makes breathing difficult. Shortness of breath may occur. The speed at which lung tissue is destroyed varies with each person.

Tobacco smoking worsens alpha-1 antitrypsin lung damage. It irritates and damages the lungs, prompting the body to send more white blood cells to protect them. The more white blood cells there are, the more neutrophil elastase is made, causing even more lung damage. The smoke itself also alters alpha-1 antitrypsin so that it cannot do as good a job protecting the lungs from harm. Smokers with alpha-1 antitrypsin deficiency have a faster rate of lung damage.

There are several ways a person can help protect the lungs from the effects of the disorder:

• receive immunizations for flu and pneumonia
• receive early treatment for lung infections by seeing the doctor at the first sign of a cold or other respiratory problem
• avoid tobacco smoke, noxious fumes, dust, and pollution
• stay fit with regular exercise
• alpha-1 antitrypsin replacement therapy

A person can also reduce symptoms of shortness of breath by doing the following:

• using medications (for example, bronchodilators, or inhaled steroids) prescribed by a doctor to help open the airways
• using oxygen if prescribed
• doing pulmonary rehabilitation (including breathing techniques).

Everyone receives one gene for alpha-1 antitrypsin from each parent. The most common type of alpha-1 antitrypsin gene is the M gene. A person who inherits an M gene from each parent has normal levels of alpha-1 antitrypsin. The Z gene is the most frequent gene that causes the disorder. If a person inherits one M gene and one Z gene, that person is a carrier of the disorder. While such a person may not have normal levels of alpha-1 antitrypsin, there should be enough to protect the lungs. The person who inherits the Z gene from each parent is called "type ZZ." This person has very low alpha-1 antitrypsin levels, allowing elastase to damage the lungs.

In rare cases, a person's body may not produce any alpha-1 antitrypsin. This condition is also inherited, and it is called "null-null type." Another type is called "dysfunctional." In this case, the alpha-1 antitrypsin levels are normal but it does not work the way it should.