α1-Antitrypsin Phenotyping
Also known as: Alpha1-Antitrypsin Phenotyping, Pi Phenotype, Protease Inhibitors
Use
Definitive analysis of hereditary α1-antitrypsin deficiency, which is associated with chronic obstructive pulmonary disease (COPD) (panacinar emphysema), hepatic cirrhosis, and hepatoma. Cholestasis with neonatal hepatitis is found in a minority of neonates with α1AT deficiency.
Special Instructions
Use high-resolution electrophoresis to detect slower electrophoretic migration variants Z and S instead of quantification by nephelometry or turbidimetry. This allows the detection of heterozygotes, enabling important family studies of potentially deficient relatives. Overnight fasting is preferred prior to specimen collection.
Limitations
α1-antitrypsin therapy may alter the patient's phenotype, potentially affecting test results. Patients may have falsely normal levels during respiratory inflammation such as bronchitis or pneumonia, requiring retesting post-illness to determine the true α1-antitrypsin level. Serum levels may be influenced by a range of conditions including pregnancy, chronic pulmonary diseases, and others.
Methodology
Immunoassay (Multiplex Protein Panel)
Biomarkers
LOINC Codes
- 6770-2
- 1825-9
- 6770-2
Result Turnaround Time
3-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
2 mL
Minimum Volume
0.7 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
Separate serum from cells.
Patient Preparation
Overnight fasting is preferred.
Storage Instructions
Room temperature storage is acceptable.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 21 days |
| Refrigerated | 21 days |
| Frozen | 21 days |
Other tests from different labs that may be relevant