ALPHA-1- ANTITRYPSIN, SERUM

Alpha-1-Antitrypsin (AAT), Serum

What it is

The Alpha-1-Antitrypsin (AAT), Serum test measures the level of alpha-1-antitrypsin in the blood. AAT is a protein produced by the liver that protects the lungs from damage caused by enzyme activity. Low levels may indicate a genetic condition called alpha-1-antitrypsin deficiency, which can lead to lung disease (such as emphysema) and liver disease.

Uses

This test is used to screen for and diagnose alpha-1-antitrypsin deficiency, evaluate patients with early-onset emphysema or unexplained chronic obstructive pulmonary disease (COPD), and assess individuals with unexplained liver disease. It may also be used to monitor people with a family history of the deficiency.

Symptoms That May Lead to the Test

Doctors may recommend this test if you have symptoms such as shortness of breath, wheezing, chronic cough, frequent lung infections, fatigue, or signs of liver disease including jaundice, swelling, or unexplained liver enzyme abnormalities. It may also be ordered for newborns or children with persistent liver issues.

Abnormal Results

Low Alpha-1-Antitrypsin: Suggests a possible inherited deficiency, which increases the risk of developing COPD, emphysema, or liver disease. Genetic testing is often recommended for confirmation.

High Alpha-1-Antitrypsin: May occur as part of the body’s acute phase response to inflammation, infection, or tissue injury, and usually does not indicate a genetic disorder.

Risks

The test requires a standard blood draw, which carries minimal risks such as mild pain, bruising, or dizziness at the puncture site. Serious complications are rare.