Alpha-1-Antitrypsin Proteotype S/Z, LC-MS/MS, Serum
Use
The test is used for the identification of homozygous and heterozygous S and Z proteotypes of alpha-1-antitrypsin deficiency, a genetic condition that can lead to lung and liver disease. Alpha-1-antitrypsin is a protein synthesized in the liver that inhibits the enzyme neutrophil elastase, protecting tissues from enzyme damage. Deficiency is associated with increased risk for early-onset emphysema and liver disease, especially in individuals of Northern European ancestry.
Special Instructions
For non-electronic ordering, complete and submit the Gastroenterology and Hepatology Test Request form with the specimen. The test combines several methods, including LC-MS/MS, to ensure comprehensive results. Discrepancies in serum levels and proteotype results may necessitate further testing, including isoelectric focusing and DNA sequencing.
Limitations
This assay will not detect 5% of the known genetic variants causing alpha-1-antitrypsin deficiency, and rare variants might result in false-negative or false-positive outcomes. Serum quantitation can be affected by external factors such as acute illness or replacement therapy. Errors in results interpretation may occur due to inaccurate or incomplete information, recent blood transfusions, or ongoing A1A replacement therapy.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 102082-5
- 6771-0
- 49244-7
Result Turnaround Time
7-14 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1.25 mL
Minimum Volume
0.5 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Causes for Rejection
Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 28 days |
| Refrigerated | 28 days |
| Frozen | 28 days |