Alpha-1 Antitrypsin Testing Test
Alpha-1 antitrypsin testing checks for a condition called alpha-1 antitrypsin deficiency (AAT deficiency). This condition means your body doesn't make enough AAT, a protein that protects your lungs from damage and is made by your liver. Low AAT levels can lead to lung disease (COPD) or liver disease (cirrhosis).
What this test measures
Alpha-1 antitrypsin testing measures the amount of AAT protein in your blood or looks for gene changes (mutations) in the SERPINA1 gene that cause AAT deficiency. There are three types: AAT blood level test, genotype test, and phenotype test.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Lower-than-normal results
If your AAT blood levels are low, it may mean you have AAT deficiency. A genotype or phenotype test is needed to confirm the diagnosis.
Frequently asked questions
What is alpha-1 antitrypsin deficiency?
It's a genetic disorder where your body doesn't make enough AAT, a protein that protects your lungs from damage. It can lead to lung disease (COPD) or liver disease (cirrhosis).
How is AAT deficiency diagnosed?
First, a blood test measures your AAT levels. If they are low, a genetic test (genotype or phenotype) is done to confirm the diagnosis.
What causes AAT deficiency?
It's caused by changes (mutations) in the SERPINA1 gene that you inherit from your parents.
What should I do if I have AAT deficiency?
Your provider may recommend treatments to prevent the condition from getting worse. You should not smoke, avoid alcohol, eat a healthy diet, exercise regularly, and take medicines as prescribed.
Can AAT deficiency be cured?
There is no cure, but treatments and lifestyle changes can help manage symptoms and prevent the condition from getting worse.
Related lab tests
Sources
- MedlinePlus: Alpha-1 Antitrypsin Testing — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.