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HelpTest Code Billings Clinic: 9210 Mayo: A1ALC Alpha-1-Antitrypsin Proteotype S/Z, LC-MS/MS, Serum
Reporting Name
A1AT Proteotype S/Z, LC-MS/MS, SPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Identification of homozygous and heterozygous S and Z proteotypes of alpha-1-antitrypsin deficiency
Method Name
A1ASZ: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
AATP: Nephelometry
A1APR: Isoelectric Focusing
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1.25 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Type
SerumSpecimen 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 |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | Reject |
| Gross icterus | OK |
Reference Values
ALPHA-1-ANTITRYPSIN:
100-190 mg/dL
ALPHA-1-ANTITRYPSIN PROTEOTYPE:
Negative for S and Z phenotype (Non S Non Z)
Interpretation
For each of the possible alpha-1-antitrypsin (A1A) genotypes there is an expected range for the total serum level of A1A. However, a number of factors can influence either the A1A serum level or the A1A proteotype results, including acute illness (A1A is an acute-phase reactant), protein replacement therapy, the presence of other rare variants, or the presence of rare DNA alterations (ie, polymorphisms). When the serum level differs from what is expected for that proteotype (ie, discordant), additional studies are performed to ensure the most appropriate interpretation of test results. Additional follow-up may include A1A phenotyping by isoelectric focusing, obtaining additional clinical information, and DNA sequencing. See Alpha-1-Antitrypsin Testing Result Table.
Day(s) Performed
Monday, Thursday
Report Available
7 to 14 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82103
82542
82104 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| A1ALC | A1AT Proteotype S/Z, LC-MS/MS, S | 102082-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| AATP | Alpha-1-Antitrypsin, S | 6771-0 |
| 34855 | A1AT Proteotype S/Z, LC-MS/MS | 49244-7 |
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| A1ASZ | A1AT Proteotype S/Z, LC-MS/MS | No | Yes |
| AATP | Alpha-1-Antitrypsin, S | Yes, (order AAT) | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| A1APR | Alpha-1-Antitrypsin Phenotype, S | Yes, (order A1APP) | No |
Testing Algorithm
If the mass spectrometry proteotype and quantitative serum level are discordant, then phenotyping will be added and performed at an additional charge.
For more information see Alpha-1-Antitrypsin-A Comprehensive Testing Algorithm