Test ID: A1APP
Alpha-1-Antitrypsin Phenotype
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
Identification of homozygous and heterozygous phenotypes of the alpha-1-antitrypsin deficiency
Profile Information
A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| A1AP2 | Alpha-1-Antitrypsin Phenotype | No | Yes |
| AATP | Alpha-1-Antitrypsin, S | Yes, (Order AAT) | Yes |
Testing Algorithm
Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
See Alpha-1-Antitrypsin-A Comprehensive Testing Algorithm in Special Instructions.
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
A1AP2/7574: Isoelectric Focusing
AATP/18066: 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
a-1-Antitrypsin, Phenotype
AAT Phenotyping
Alpha 1 Antitrypsin
Alpha-1-Antitrypsin Reflex (Order 80812)
Anti-Alpha-1-Trypsin
Antitrypsin
Antitrypsin, Phenotype
Pi Typing (Alpha-1-Antitrypsin Phenotyping)
Protease Inhibitor Allo Typing
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:
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 1.25 mL
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 | Mild reject; Gross reject |
| Lipemia | Mild OK; Gross OK |
| Icterus | Mild OK; Gross OK |
| 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 |
|---|---|---|
| Serum | Refrigerated (preferred) | 14 days |
| Frozen | 14 days | |
| Ambient | 72 hours |
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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.
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.
ALPHA-1-ANTITRYPSIN
100-190 mg/dL
ALPHA-1-ANTITRYPSIN PHENOTYPE
Most normal individuals have the M phenotype (M, M1, or M2). Over 99% of M phenotypes are genotypically MM. In the absence of family studies, the phenotype (M) and quantitative level can be used to infer the genotype (MM). The most common alleles associated with a quantitative deficiency are Z and S. The reports for the rare alleles will indicate whether or not they have been associated with reduced quantitative levels.
Interpretation
Provides information to assist in interpretation of the test results
There are >40 alpha-1-antitrypsin (A1A) phenotypes (most of these are associated with normal quantitative levels of protein). The most common normal phenotype is M (M, M1, or M2), and >90% of Caucasians are homozygous M (MM) genotype.
A1A deficiency is usually associated with the Z phenotype (ZZ genotype), but genotypes such as SS and SZ are also associated with decreased A1A levels.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This assay does not determine genotype. Genotyping is less variable and more specific than phenotype testing. For genotyping, see A1ATR/83050 Alpha-1-Antitrypsin Deficiency Profile, Mayo's preferred test for diagnosing alpha-1-antitrypsin (A1A) deficiency. A1ATR/83050 includes both A1A quantitation and genotyping; phenotyping is automatically performed when the patient's A1A value and genotype are not diagnostic.
If 2 bands are seen, such as an M band and a Z bands, it is reported as MZ (the equivalent of the genotype).
If 1 band is seen, such as the Z band and the quantitative level is consistent with a homozygote, the phenotype is assumed to be homozygous and is reported as ZZ.
Clinical Reference
Provides recommendations for further in-depth reading of a clinical nature
Morse JO: Alpha-1-antitrypsin deficiency. N Engl J Med 1978;299:1045-1048; 1099-1105
Method Description
Describes how the test is performed and provides a method-specific reference
The phenotyping is done by isoelectric focusing in agarose gels.
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 Friday; 9 a.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
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-Alpha-1-antitrypsin
82104-Alpha-1-antitrypsin phenotype
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 |
|---|---|---|
| AATP | Alpha-1-Antitrypsin, S | 6771-0 |
| 8166 | Alpha-1-Antitrypsin Phenotype | 32769-2 |


