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HelpTest ID: AAT Alpha-1-Antitrypsin, Serum
Reporting Name
Alpha-1-Antitrypsin, SUseful For
Workup of individuals with suspected disorders such as familial chronic obstructive lung disease
Diagnosing alpha-1-antitrypsin deficiency
Testing Algorithm
For more information see Alpha-1-Antitrypsin-A Comprehensive Testing Algorithm.
Specimen Type
SerumSpecimen Required
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | |
| Ambient | 28 days | ||
| Frozen | 28 days |
Special Instructions
Reference Values
100-190 mg/dL
Day(s) Performed
Monday through Friday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
82103
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| AAT | Alpha-1-Antitrypsin, S | 6771-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| AAT | Alpha-1-Antitrypsin, S | 6771-0 |
Clinical Information
Alpha-1-antitrypsin (A1A) is the most abundant serum protease inhibitor, and it inhibits trypsin and elastin as well as several other proteases. The release of proteolytic enzymes from plasma onto organ surfaces and into tissue spaces results in tissue damage unless inhibitors are present. Congenital deficiency of A1A is associated with the development of emphysema at an unusually early age and with an increased incidence of neonatal hepatitis, usually progressing to cirrhosis.
For more information see Alpha-1-Antitrypsin-A Comprehensive Testing Algorithm.
Interpretation
Patients with serum levels less than 70 mg/dL may have a homozygous deficiency and are at risk for early lung disease. Alpha-1-antitrypsin proteotype testing should be done to confirm the presence of homozygous deficiency alleles.
If clinically indicated, patients with serum levels less than 125 mg/dL should have proteotype testing in order to identify heterozygous individuals. Heterozygotes do not appear to be at increased risk for early emphysema.
Clinical Reference
1. Tejwani V, Stoller JK: The spectrum of clinical sequelae associated with alpha-1 antitrypsin deficiency. Ther Adv Chronic Dis. 2021 Jul;12_suppl. doi: 10.1177/2040622321995691
2. Patel D, McAllister SL, Teckman JH: Alpha-1 antitrypsin deficiency liver disease. Transl Gastroenterol Hepatol. 2021 Apr 5;6:23. doi: 10.21037/tgh.2020.02.23
3. Donato LJ, Snyder MR, Greene DN: Measuring and interpreting serum AAT concentration. Methods Mol Biol. 2017;1639:21-32. doi: 10.1007/978-1-4939-7163-3_3
Report Available
1 to 3 daysMethod Name
Nephelometry
Forms
If not ordering electronically, complete, print, and send 1 of the following with the specimen:
-Gastroenterology and Hepatology Test Request (T728)
-General Request (T239)
mml-gi-liver-genetic