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HelpTest Code A1AFS Alpha-1-Antitrypsin Clearance, Feces and Serum
Ordering Guidance
The recommended procedure for protein-losing enteropathy is A1AFS / Alpha-1-Antitrypsin Clearance, Feces and Serum.
Shipping Instructions
Feces and serum should be shipped together. Specimens shipped separately may delay testing.
Specimen Required
Both feces and serum are required.
Blood must be drawn during the stool collection period.
Specimen Type: Serum
Collection Container/Tube: Red top or serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Centrifuge within 2 hours.
2. Aliquot and ship in plastic vial.
Specimen Type: Feces
Supplies: Stool Containers - 24, 48, 72 Hour Kit (T291)
Container/Tube: Stool container
Specimen Volume: Entire collection
Collection Instructions:
1. Collect a 24-hour fecal collection.
2. If no specimen is obtained within 24 hours, extend collection time to 48 to 72 hours. Document time frame.
Useful For
Diagnosing protein-losing enteropathies
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| AATS | Alpha-1-Antitrypsin, S | No | Yes |
| A1ATF | Alpha-1-Antitrypsin, 24 Hr, F | No | Yes |
Reporting Name
Alpha-1-Antitrypsin ClearanceSpecimen Type
FecalSerum
Specimen Minimum Volume
Homogenized feces: 1 mL
Serum: 0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Fecal | Frozen (preferred) | 14 days | |
| Ambient | 14 days | ||
| Refrigerated | 14 days | ||
| Serum | Frozen (preferred) | 28 days | |
| Ambient | 28 days | ||
| Refrigerated | 28 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
| Feces collected in any preservative or fixative | Reject |
Reference Values
CLEARANCE:
≤27 mL/24 hours
FECAL ALPHA-1-ANTRYPSIN CONCENTRATION:
≤54 mg/dL
SERUM ALPHA-1-ANTRYPSIN CONCENTRATION:
100-190 mg/dL
Supportive Data
Protein-losing enteropathy has been studied by intravenous injection of radioactive chromium chloride or labeled human serum albumin. The correlation between radiochromium and stool alpha-1-antitrypsin clearance has been measured with excellent correlation coefficients.
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysSpecimen Retention Time
Serum/2 weeks; Stool/Aliquot 2 weeksPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82103 x 2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| A1AFS | Alpha-1-Antitrypsin Clearance | 93419-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| AAT24 | Alpha-1-Antitrypsin, 24 Hr, F | 9407-8 |
| AATS | Alpha-1-Antitrypsin, S | 6771-0 |
| CRCLR | Clearance | 18271-7 |
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.