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Test ID: A1APP
Alpha-1-Antitrypsin Phenotype

Secondary ID A test code used for billing and in test definitions created prior to November 2011

26953

NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

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 IDReporting NameAvailable SeparatelyAlways Performed
A1AP2Alpha-1-Antitrypsin PhenotypeNoYes
AATPAlpha-1-Antitrypsin, SYes, (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

Alpha-1-Antitrypsin Phenotype

Aliases Lists additional common names for a test, as an aid in searching

A1A Phenotyping
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

Serum

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.

0.5 mL

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 TypeTemperatureTime
SerumRefrigerated (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.

2 days

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

6 days

Performing Laboratory Location The location of the laboratory that performs the test

Rochester

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.

This test has been cleared or approved by the U.S. 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 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 IDReporting NameLOINC Code
AATPAlpha-1-Antitrypsin, S6771-0
8166Alpha-1-Antitrypsin Phenotype32769-2