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HelpTEST ID A1AF Alpha-1-Antitrypsin, Random, Feces
Reporting Name
Alpha-1-Antitrypsin, Random, FSpecimen Type
FecalOrdering Guidance
The preferred test for diagnosing protein-losing enteropathies is A1AFS / Alpha-1-Antitrypsin Clearance, Feces and Serum.
Specimen Required
Supplies:
-Stool container, Small (Random), 4 oz (T288)
-Stool Collection Kit, Random (T635)
Container/Tube: Stool container
Specimen Volume: 5 g
Collection Instructions: Collect a random fecal specimen.
Specimen Minimum Volume
Homogenized stool: 1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Fecal | Frozen (preferred) | 14 days |
| Ambient | 14 days | |
| Refrigerated | 14 days |
Method Name
Nephelometry
Reject Due To
| Collected in any preservative or fixative | Reject |
Reference Values
≤54 mg/dL
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysSpecimen Retention Time
14 days; supernatant aliquot only, the feces are discarded after processingPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82103
Useful For
Diagnosing protein-losing enteropathies, especially when used in conjunction with serum alpha-1-antitrypsin (AAT) levels as a part of AAT clearance studies
Clinical Information
Alpha-1-antitrypsin (AAT) is a 54-kDa glycoprotein that is resistant to degradation by digestive enzymes and is, therefore, used as an endogenous marker for the presence of blood proteins in the intestinal tract. AAT clearance is reliable for measuring protein loss distal to the pylorus. A serum sample is required to interpret results as a serum deficiency of AAT would make the AAT fecal excretion lower and could invalidate the test utility.
Gastrointestinal protein enteropathy has been associated with regional enteritis, sprue, Whipple intestinal lipodystrophy, gastric carcinoma, allergic gastroenteropathy, intestinal lymphangiectasia, constrictive pericarditis, congenital hypogammaglobulinemia, and iron deficiency anemia associated with intolerance to cow's milk. Increased fecal excretion of AAT can be found in small and large intestine disease and is applicable to adults and children.