Ordering Recommendation

Preferred test to identifiy alpha-1-antitrypsin deficiency and causative DNA and protein variants.

Mnemonic
A1A GENO
Methodology

Immunoturbidimetry/Polymerase Chain Reaction/Fluorescence Monitoring/Isoelectric Focusing

Performed

Varies

Reported

2-10 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Serum separator tube AND lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Allow serum to clot completely at room temperature. Separate serum from cells ASAP or within 2 hours of collection. Transport 0.5 mL serum AND 3 mL whole blood. (Min: 0.5 mL serum AND 0.5 mL whole blood)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Serum: Ambient: 1 week; Refrigerated: 3 months; Frozen: 3 months (avoid repeat freeze/thaw cycles)
Whole Blood:
Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month.

Reference Interval
Test Number
Components
Reference Interval
0050001 Alpha-1-Antitrypsin Effective November 17, 2014
90-200 mg/dL
  Alpha-1-Antitrypsin Phenotype

Interpretive Data

Background Information for A1A (SERPINA1) Enzyme Concentration and 2 Mutations with Reflex to A1A Phenotype:
Characteristics of Alpha-1-Antitrypsin (AAT) Deficiency:
Coughing, wheezing, bronchiectasis, chronic obstructive pulmonary disease, emphysema, and cirrhosis.
Incidence:
1 in 3000 to 5000 North American individuals.
Inheritance:
Autosomal recessive.
Cause:
Two pathogenic mutations in the SERPINA1 gene on opposite chromosomes.
Clinical Sensitivity:
95 percent.
Mutations Tested:
S allele (c.791A>T) and Z allele (c.1024G>A).
Methods:
Genotyping performed by PCR followed by fluorescent probe melting analysis; AAT protein concentration measured using immunoturbidmetric assay; phenotyping performed by isoelectric focusing electrophoresis. Genotyping and AAT serum protein concentration determination are performed on all specimens. Protein phenotyping is only performed on specimens that have AAT protein concentrations of less than 90 mg/dL and are not homozygous or compound heterozygous for the S or Z deficiency alleles by genotyping..  
Analytical Sensitivity and Specificity:
99 percent.
Limitations:
SERPINA1 mutations, other than the S (c.791A>T) and Z (c.1024G>A) alleles, will not be detected. Diagnostic errors can occur due to rare sequence variations.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

Compliance Category

Laboratory Developed Test (LDT)

Note

Alpha-1-antitrypsin serum protein concentration determination and A1A genotyping are performed on all specimens. If two deficiency alleles (ZZ, SZ, or SS) are detected, then no further testing will be added. If the protein concentration is less than 90 mg/dL and only one or no deficiency allele is detected by A1A genotyping, then phenotyping will be added. Additional charges apply.

Hotline History
N/A
CPT Codes

82103; 81332; if reflexed, add 82104

Components
Component Test Code* Component Chart Name LOINC
0050001 Alpha-1-Antitrypsin 1825-9
0051259 Alpha-1-Antitrypsin S Allele 1829-1
0051260 Alpha-1-Antitrypsin Z Allele 1831-7
0051261 Alpha-1-Antitrypsin Interpretation 1830-9
0089005 Alpha-1-Antitrypsin Phenotype 49244-7
2001289 Alpha-1-Antitrypsin Genotype Specimen 31208-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • A-1-Antitrypsin
  • A1A
  • AAT
  • Alpha 1 Antitrypsin
  • Alpha 1 Antitrypsin Genotype
  • Alpha one Antitrypsin
  • Alpha1-Protease Inhibitor
  • Anti-Alpha-1-Trypsin
  • Antitrypsin
  • Phenotype
  • Phenotyping
  • Pi Typing
  • Prolastin
  • Protease I
Alpha-1-Antitrypsin (SERPINA1) Enzyme Concentration and 2 Mutations with Reflex to Alpha-1-Antitrypsin Phenotype