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Test Code LAB810 Alpha-1-Antitrypsin, Serum

Additional Codes

AAT

Useful For

Workup of individuals with suspected disorders such as familial chronic obstructive lung disease

 

Diagnosing alpha-1-antitrypsin deficiency

Testing Algorithm

For more information see Alpha-1-Antitrypsin-A Comprehensive Testing Algorithm.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reference Values

100-190 mg/dL

Day(s) Performed

Monday through Friday

CPT Code Information

82103

LOINC Code Information

Test ID Test Order Name Order LOINC Value
AAT Alpha-1-Antitrypsin, S 6771-0

 

Result ID Test Result Name Result LOINC Value
AAT Alpha-1-Antitrypsin, S 6771-0

Interpretation

Patients with serum levels less than 70 mg/dL may have a homozygous deficiency and are at risk for early lung disease. Alpha-1-antitrypsin proteotype testing should be done to confirm the presence of homozygous deficiency alleles.

 

If clinically indicated, patients with serum levels less than 125 mg/dL should have proteotype testing in order to identify heterozygous individuals. Heterozygotes do not appear to be at increased risk for early emphysema.

Method Description

In this Siemens Nephelometer II method, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.

 

A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with an LED, which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is yet formed. An antigen-antibody complex is formed in the final measurement.

 

The result is calculated by subtracting value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Unpublished Mayo method; instruction manual: Siemens Nephelometer II. Siemens, Inc; Version 2.3, 2008; Addendum to the Instruction Manual 2.3, 08/2017)

Report Available

1 to 3 days

Specimen Retention Time

14 days

Reject Due To

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

Method Name

Nephelometry

Secondary ID

8161