Alpha-1 Antitrypsin Clearance, 24-Hour, Serum/Plasma and Urine — Volume Rate
Measures how quickly alpha-1 antitrypsin is cleared from the blood using serum or plasma levels and a 24-hour urine collection.
["This test estimates the rate at which alpha-1 antitrypsin is lost through the urine."]
Key facts at a glance
- LOINC
- 18271-7
- Short code
- A1AT Cl 24h SerPl+Stl-vRate
- Synonyms
- A1AT Cl 24h SerPl+Stl-vRate
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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
What is this test?
Alpha-1 antitrypsin is a protein that travels in the blood and helps protect the lungs. This test estimates how quickly the protein is cleared from the blood, usually by combining a serum or plasma measurement with the amount found in urine collected over 24 hours.
Why might I need this test?
It may be ordered to evaluate how the kidneys handle alpha-1 antitrypsin or to assess unusual urinary protein loss. Results are generally interpreted with other kidney tests, urine protein measurements, and your medical history.
How is the test performed?
A blood sample is used to measure the alpha-1 antitrypsin level in serum or plasma. If a 24-hour urine collection is required, all urine is collected for the specified period, and the clearance rate is calculated from the blood and urine results.
How do I prepare for the test?
Follow the collection instructions provided by your healthcare professional. For a 24-hour urine test, collect every sample during the specified period and store the container as directed. Ask whether any medications or dietary changes should be adjusted.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An abnormal clearance rate may indicate that alpha-1 antitrypsin is being lost unusually quickly or that its blood level is changing for another reason. Low serum alpha-1 antitrypsin can also occur with inherited deficiency, liver disease, or protein-losing conditions, so the result must be interpreted alongside the individual blood and urine findings.
Short name
24-hour alpha-1 antitrypsin clearance
Frequently asked questions
Is this the same as a routine alpha-1 antitrypsin blood test?
Why is a 24-hour urine collection needed?
Does an abnormal result diagnose alpha-1 antitrypsin deficiency?
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 16, 2026. · Read our editorial policy