Alpha 1 antitrypsin is a type of protein produced in the liver and deficiency of this protein can cause liver problems and lung disease. A1AD is a genetic disorder inherited by birth. Any deficiency of this protein can damage the alveolar walls of the lungs. Normal serum level of A1A is about 20-60 umol/L and it can cause lung damage if the level goes below 15. Children having COPD (Chronic Obstructive Pulmonary Disease) should be checked for A1AT deficiency to prevent liver and lungs damage. A1AT is common disorder in white people and more particular in North western European countries.
A1AT is a under-diagnosed disorder and young children having frequent episodes of congestion may have this deficiency. About 10-15% of adults having A1AT disorder are likely to develop liver problems. There is no cure for A1AT but with early diagnosis symptoms can be managed and possible liver damage can be prevented. A1AT is also known as genetic emphysema, Alpha 1 emphysema and hereditary pulmonary emphysema.
Symptoms :
Initial signs of A1AT can appear even before 20 years. Some of the common symptoms include shortness of breath, wheezing, breathlessness while doing exercise, loss of weight, repeated respiratory infections, rapid heartbeat and extreme tiredness. The symptoms will increase steadily as the person smokes causing more damage to the lungs.
Some people may develop emphysema having symptoms of persistent cough, difficulty in breathing and barrel shaped chest. If the disease has progressed to cause liver damage the person may show symptoms like swollen legs or feet, swollen abdomen and yellow coloration of the skin.
Causes :
A1AT is an inherited disorder and the defective genes are passed on to the children. A genetic mutation in SERPINA1 gene is likely to cause A1AT disorder. This gene is responsible for producing antitrypsin protein which protects the body from neutrophil elastase. Actually elastase enzyme is meant for fighting infection, but if the level of A1AT is too low this enzyme can attack and destroy the lung walls called alveoli. This can lead to emphysema, a life threatening lung damage.
The defective gene of SERPINA1 is inherited by autosomal codominant method. People with two copies of M allele version will not develop A1AT deficiency. People having S allele version will have reduced production of antitrypsin enzyme and people with Z allele will have almost no enzyme secretion and they are prone to develop this disorder. Some people may have combination of version like SZ or SM or MZ and smoking considerably increases the risk of lung disorders. It is not true that every person with A1AT disorder would develop liver problem. Those having ZZ version are more likely to develop lungs and liver problems.
Tests :
Children with a history of A1AT disorder should be screened for serum levels frequently. The doctor will complete the physical exam and the symptoms. He would listen to the wheezing sound or shortness of breath using a stethoscope. He may order for blood test to identify Alpha 1 genotype, Alpha 1 antitrypsin test to find out the level of this protein serum in your blood. He may also order for imaging tests like chest X-ray to check how far the damage has been done. If he suspects liver problems he may conduct liver biopsy and liver function test.
Treatment :
A1AT disorder cannot be treated but the symptoms can be controlled. People with low levels of antitrypsin should be watched for symptoms. Such people will be advised to quit smoking to prevent early lung damage. Method of treatment varies with that of individual’s symptoms. Your doctor would prescribe suitable bronchodilators to control respiratory tract infection. People with COPD are given pulmonary rehabilitation. Such people can benefit by taking yearly shots of influenza vaccines. In severe cases lung surgery and transplantation is done. Liver problems can be managed by effective medications and specific diet. In extreme cases of liver failure, liver transplant is done.
Prognosis :
Those who are diagnosed with A1AT disorder in early stages (through screening tests before symptoms have developed) have better prognosis. Individuals diagnosed with COPD are likely to have Alpha 1 deficiency. A1AT is the top most risk factor causing emphysema. Hence everyone with COPD should be screened for Alpha 1.