Alpha 1 Antitrypsin

Test Codes

EPIC: LAB8100, Beaker: A1AT, Antrim: 30050

Department

Chemistry

Specimen Collection Criteria

Collect: One Gold-top SST tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2–8°C or 36–46°F) the centrifuged collection tube within twelve hours of collection.

Preparation for Courier Transport

Transport: Centrifuged collection tube, refrigerated (2–8 °C or 36–46 °F). (Minimum: 0.5 mL)

Rejection Criteria

• Grossly lipemic specimens.
• Hemolyzed specimens.
• Plasma specimens.

In-Lab Processing

Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Deliver immediately to the appropriate testing station.

Storage

Specimen Stability for Testing:

Centrifuged SST Tubes and Microtainers^® with Separator Gel
Room Temperature (20–26°C or 68–78.8°F): 12 hours
Refrigerated (2–8°C or 36–46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Red-top Tubes and Microtainers^® without Separator Gel
Room Temperature (20–25°C or 68–77°F): 12 hours
Refrigerated (2–8°C or 36–46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20–26°C or 68–78.8°F): 12 hours
Refrigerated (2–8°C or 36–46°F): 7 days
Frozen (-20°C/-4°F or below): 3 months

Specimen Storage in Department Prior to Disposal:

Refrigerated (2–8°C or 36–46°F): 7 days

Laboratory

Dearborn Chemistry Laboratory
Royal Oak Automated Chemistry Laboratory

Performed

Sunday – Saturday, 24 hours a day.
Results available within 24 hours.

Reference Range

100-240 mg/dL.

Test Methodology

Immunoturbidimetric.

Interpretation

Alpha-1-antitrypsin, a serine protease, is one of the major inhibitors of proteolytic enzymes found in human plasma. Increased concentrations of alpha-1-antitrypsin are found in inflammatory or conditions in which other acute phase reactants are also increased. The level begins to increase after 1 day and peaks at 3-4 days. Decreased levels of alpha-1-antitrypsin may be associated with chronic obstructive pulmonary disease and liver disease (particularly in infants).

NOTE: Because AAT is increased in the presence of acute inflammation, interpretation should be made with caution if a deficiency is being considered. A normal C Reactive Protein (CRP) level can be useful to exclude acute inflammation.

Clinical Utility

More than 70 genetic variants of alpha-1-antitrypsin (AAT) have been described. Not all of these are associated with decreased AAT levels or with clinical disease. An individual homozygous for PiZ has about 15% normal AAT and Pi null has no AAT. Such individuals are at significantly increased risk for development of pulmonary emphysema at an earlier age than individuals with a normal AAT phenotype; this process is accelerated by smoking. Development of liver disease may occur in infants (hepatitis and cirrhosis) and in older individuals (chronic hepatitis and cirrhosis). In individuals with a decreased level of AAT, Alpha 1 Antitrypsin Phenotyping is recommended.

CPT Codes

82103

Contacts

Last Updated

7/21/2024