Test ID: A1AF
Alpha-1-Antitrypsin, Random, Feces
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Diagnosing protein-losing enteropathies, especially when used in conjunction with serum alpha-1-antitrypsin (A1A) levels as a part of A1A clearance studies (see CA1A/8835 Alpha-1-Antitrypsin Clearance, Feces and Serum; preferred test)
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
The recommended procedure for protein-losing enteropathy is CA1A/8835 Alpha-1-Antitrypsin Clearance, Feces and Serum.
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Nephelometry
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Alpha 1 Antitrypsin
Alpha-1-Antitrypsin, Feces Only
Antitrypsin, Feces
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Stool container (Supply T288)
Specimen Volume: 5 g
Collection Instructions:
1. Collect a random stool specimen.
2. See Stool Collection Information Sheet in Special Instructions.
Forms: If not ordering electronically, submit a General Request Form (Supply T239) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Fecal | Frozen (preferred) | 14 days |
| Ambient | 14 days | |
| Refrigerated | 14 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Alpha-1-antitrypsin (A1A) 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. A1A clearance is reliable for measuring protein loss distal to the pylorus.
Gastrointestinal protein enteropathy has been associated with regional enteritis, sprue, Whipple's intestinal lipodystrophy, gastric carcinoma, allergic gastroenteropathy, intestinal lymphangiectasia, constrictive pericarditis, congenital hypogammaglobulinemia, and iron deficiency anemia associated with intolerance to cow's milk.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
< or =54 mg/dL
Interpretation Provides information to assist in interpretation of the test results
Patients with protein-losing enteropathies generally have alpha-1-antitrypsin stool concentrations >100 mg/mL.
Borderline elevations above the normal range are equivocal for protein-losing enteropathies.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The clearance studies using 24-hour stool specimens and serum determinations are preferred in order to normalize the large range of serum alpha-1-antitrypsin (A1A) concentrations and the variability in random stool A1A concentration. In the absence of either a 24-hour stool collection or a contemporary serum specimen, the fecal concentration of A1A can be used as a surrogate marker.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Florent C, L'Hirondel C, Desmazures C, et al: Intestinal clearance of alpha 1-antitrypsin. A sensitive method for the detection of protein losing enteropathy. Gastroenterology 1981;81:777-780
2. Crossley JR, Elliott RB: Simple method for diagnosing protein-losing enteropathy. Br Med J 1977;1:428-429
3. Perrault J, Markowitz H: Protein-losing gastroenteropathy and the intestinal clearance of serum alpha-1-antitrypsin. Mayo Clin Proc 1984;59:278-279
Method Description Describes how the test is performed and provides a method-specific reference
Nephelometry. Immunonephelometry quantitates the alpha-1-antitrypsin (A1A) contained in a stool specimen. In the absence of a timed stool collection, an A1A stool concentration will be reported.(Instruction manual: Siemens Nephelometer II. Siemens, Inc., Newark, DE)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday; Continuously until 2 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
82103
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| AAT_F | Alpha-1-Antitrypsin, Random, F | 9407-8 |
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