Alpha-1 Antitrypsin (A1AT) Serum Protein Level
This test measures the level of Alpha-1 Antitrypsin, a protein produced by the liver that helps protect the lungs from damage caused by enzymes released during inflammation.
["Alpha-1 Antitrypsin levels help assess lung and liver health, particularly in conditions like emphysema or chronic lung disease."]
Key facts at a glance
- LOINC
- 40534-0
- Short code
- RBC # DiafP Manual
- Synonyms
- RBC # DiafP Manual
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- CPT
- 85041
- SNOMED
- 900000000000003001
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if you have symptoms of lung issues (such as shortness of breath, chronic cough) or liver problems (like jaundice, fatigue). It may also be used to monitor conditions like alpha-1 antitrypsin deficiency, which can lead to lung disease or cirrhosis over time.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample. If you’re on blood thinners, let your provider know before the test.
What the Results Mean
Results can vary based on your health and medical history. Low levels may indicate a genetic deficiency, while high levels could be linked to liver disease or certain medications. Your provider will discuss findings in the context of your overall health.
Common Conditions Linked to Results
Low levels of Alpha-1 Antitrypsin are often associated with alpha-1 antitrypsin deficiency, which can cause chronic obstructive pulmonary disease (COPD) or liver disease. High levels may be seen in conditions like cirrhosis or certain infections.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Alpha-1 Antitrypsin plays a critical role in protecting lung tissue from enzymes released during inflammation. Deficiencies can lead to progressive lung damage (like emphysema) or liver disease. Regular monitoring is important for those with a genetic predisposition to these conditions.
Short name
Alpha-1 Antitrypsin
Frequently asked questions
What causes abnormal Alpha-1 Antitrypsin levels?
How often should I get this test?
Can diet or lifestyle changes affect Alpha-1 Antitrypsin levels?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy