Alpha-1 Antitrypsin (A1AT) Serum Concentration Confirmation Test
This test measures the level of Alpha-1 Antitrypsin, a protein that helps protect your lungs and liver from damage caused by enzymes released during inflammation.
["A1AT levels help assess risk for lung diseases like emphysema or liver conditions like cirrhosis."]
Key facts at a glance
- LOINC
- 42215-4
- Short code
- nRBC NFr Mar Manual
- Synonyms
- nRBC NFr Mar 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 Is Done
Your healthcare provider may order this test if you have symptoms of lung or liver disease, a family history of these conditions, or if you have a known genetic mutation related to A1AT deficiency. It’s often used to confirm or monitor treatment for conditions linked to low A1AT levels.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if serum is the specimen type. Bring any medications you’re taking, as some may affect results.
During the Test
A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick and usually painless. The blood sample is then sent to a lab for analysis.
What the Results Mean
Results are compared to a reference range to determine if your A1AT level is low, normal, or high. Low levels may indicate genetic disorders or conditions like chronic obstructive pulmonary disease (COPD) or cirrhosis. High levels might be seen in certain inflammatory conditions.
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.
◆Associated findings1
Short name
A1AT Confirmation
Frequently asked questions
Low Alpha-1 Antitrypsin levels are strongly linked to lung diseases like emphysema and liver diseases like cirrhosis. If you have a family history of these conditions or symptoms such as persistent coughing, shortness of breath, or jaundice, this test can help identify whether you’re at risk.
A low A1AT level suggests you may have a genetic mutation that reduces your body’s ability to produce enough of this protective protein. This can increase your risk of developing lung diseases or liver damage over time. Your doctor may recommend monitoring or treatment to manage symptoms.
Can diet or lifestyle changes affect A1AT 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