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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
Diagnosis of alpha-1-antitrypsin deficiency
Testing Algorithm
See Alpha-1-Antitrypsin-A Comprehensive Testing Algorithm in Special Instructions.
Specimen Type
SerumSpecimen Required
Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 1 mL
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 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.
See Alpha-1-Antitrypsin-A Comprehensive Testing Algorithm in Special Instructions.
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 proteotyping should be done to confirm the presence of homozygous deficiency alleles.
If clinically indicated, patients with serum levels less than 125 mg/dL should be proteotyped in order to identify heterozygous individuals. Heterozygotes do not appear to be at increased risk for early emphysema.
Clinical Reference
1. Kanakoudi F, Drossou V, Tzimouli V, et al: Serum concentrations of 10 acute-phase proteins in healthy term and pre-term infants from birth to age 6 months. Clin Chem. 1995;41:605-608
2. Morse JO: Alpha-1-antitrypsin deficiency. N Engl J Med. 1978;299:1045-1048, 1099-1105
3. Cox DW: Alpha-1-antitrypsin deficiency. In: Scriver CR, Beaudet AL, Sly WS, Valle D, eds. The Metabolic and Molecular Basis of Inherited Disease. Vol 3. 7th ed. McGraw-Hill Book Company; 1995:4125-4158
Report Available
1 to 2 daysMethod Name
Nephelometry
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Client Test Request (T728) with the specimen.
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