Alpha-1 Antitrypsin Deficiency
Alpha-1 – antitrypsin deficiency is a hereditary disease that may lead to hepatitis and cirrhosis. It is the most common genetic cause of liver disease in children. Adults are also affected and may have lung involvement with emphysema as well as liver disease. The protein alpha-1 – antitrypsin is a substance made in the liver. It plays an important role preventing the breakdown of enzymes in various organs of the body.
A child must inherit the tendency from both parents to develop the disease, alpha-1 -antitrypsin deficiency. The incidence of the disease in the United States is approximately 1:2000 live births. Fortunately, for reasons that are not understood, only 10-20% of the babies born with the deficiency will have liver disease. Decreased levels of the serum protein, alpha-1 – antitrypsin, lead to liver damage with scarring and abnormal liver function.
The disease most often appears in the newborn period with jaundice, swelling of the abdomen, and poor feeding. It may also appear in late childhood or adulthood and be detected because of fatigue, poor appetite, swelling of the abdomen and legs or abnormal liver tests.
The diagnosis is made by blood tests when the serum level of alpha-1 – antitrypsin is low and standard liver function tests are abnormal. Other tests such as urine collection, ultrasound examination, or tests using specialized X-ray techniques may be necessary. A biopsy of the liver (sampling liver tissue with a needle or by operation) is usually performed to look for liver injury. Relatives who are carriers but do not have the disease can also be diagnosed by blood tests.
Currently, there is no cure for this disease. However, certain abnormalities can be treated or controlled. Treatment is designed to maintain normal nutrition, to provide the liver and the body with essential nutrients, and to identify complications early in order to treat them better. Multiple vitamins and vitamins E, D and K are often given. When jaundice is severe or itching appears, phenobarbital or cholestyramine may be used. If the disease progresses, excess body fluid may occur and can be treated with diuretics.
Patients who develop cirrhosis (scarring of the liver) have changes in blood flow through the liver which produce other complications: nosebleeds, bruising, excess body fluid, enlarged veins in the inside of the stomach and esophagus (varices). Occasionally, increases in pressure in these veins make them leak, and internal bleeding may result. Increased sleepiness after eating protein (due to increased blood ammonia levels) and increased risk of infection may be late complications.
The long-term outcome of the disease is variable. Approximately 25% of affected patients develop cirrhosis and its complications, but 75% of individuals will not have any significant liver disease after the newborn period. Some patients with cirrhosis lead relatively normal lives for relatively long periods of time. The reason for this difference is not known. Liver transplantation can be done when liver failure develops and interferes with normal functioning at school, work or in the home