Alpha-1 antitrypsin Health Article

Diagnosis

Alpha-1 antitrypsin may be suspected in a newborn with cholestatic jaundice, swollen abdomen, and poor feeding. In later childhood or adulthood, fatigue, poor appetite, swelling of the abdomen and legs, or abnormal liver tests may trigger the need for testing. The diagnosis of alpha-1 antitrypsin is based on measurement of antitrypsin (Pi) in the blood. If levels of Pi are deficient, genetic studies may be performed to determine which abnormal forms of the gene are present. The Pi protein can also be studied to determine which type a person has. Prenatal diagnosis is available, however, it is recommended that parental genetic studies precede prenatal testing to ensure accurate interpretation of results.

Levels of antitrypsin protein in the blood may be normal in individuals who have one PI Z gene and one normal gene, and in individuals who have one PI S gene and one PI Z gene. Studying the Pi protein will more accurately diagnose these individuals.

Lung disease in people with alpha-1 antitrypsin is diagnosed by the same methods used to diagnose lung disease in people who do not have alpha-1 antitrypsin. These studies include breathing tests such as total lung capacity and pulmonary function tests. Total lung capacity is measured with a device called a spirometer. Pulmonary function tests measure oxygen/carbon dioxide exchange by determining the amount of air exhaled, the time to exhale, and the efficiency of oxygen transport. X rays and other studies may also be performed.

Liver disease in children and adults with alpha-1 antitrypsin is diagnosed by the same methods used to diagnose liver disease in people who do not have alpha-1 antitrypsin. Liver function studies include tests measuring two liver proteins called serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT). SGOT is sometimes called aspartate transaminase (AST), and SGPT is sometimes called alanine aminotransferase (ALT). Studies may also be performed looking for deposits within the cells of the liver called inclusions.

Once the diagnosis of alpha-1 antitrypsin has been made, it is important to share this information with relatives related by blood, especially parents and children. These relatives may also have alpha-1 antitrypsin. If they know that they have it before they develop lung disease, they can take preventative measures such as avoiding exposure to smoke and other lung toxins. Some organizations have recommended that individuals with asthma be tested for alpha-1 antitrypsin.

Treatment and management

Although alpha-1 antitrypsin cannot be prevented, many of the condition's consequences can be prevented. People with alpha-1 antitrypsin should not smoke cigarettes and should not be exposed to smoke or other lung irritants. Respiratory infections should be treated promptly because they increase the level of harmful elastase in the lungs. Some doctors recommend avoiding alcohol and oxidants; keeping hepatitis A and B vaccinations, pneumococcal vaccinations, and influenza shots up-to-date; and preventing hepatitis C exposure.

Protein augmentation

Treatment is available if individuals with alpha-1 antitrypsin develop lung disease. Infusion of alpha-1 antitrypsin protein into the bloodstream may halt or slow progression of respiratory problems. The protein is put into a blood vein weekly, biweekly, or monthly. Treatment with the replacement protein may not be effective if tissue damage to the lungs is severe. This is often called augmentation therapy. This therapy is safe and people who receive it have few adverse reactions. However, some researchers are not convinced that it is an effective treatment.

People with alpha-1 antitrypsin who have diminished lung air capacity but no other symptoms may be given prophylactic replacement antitrypsin infusions. In the year 2000, the success of prophylactic treatment has not been confirmed. The controversy over augmentation therapy may be resolved in 2001. A task force currently addressing this issue and others is scheduled to publish treatment and standard of care recommendations at that time.

Treatments in development

People who have two abnormal PI genes have reason to be hopeful that effective treatments may be available by 2010. The Pi protein may be available in an inhaled form in the first few years of the new millennium. Biotechnology based treatments such as aerosols that deliver the normal gene to lung tissue are being studied. Lung transplant may be an option in the future.