Alpha-1-Antitrypsin Phenotype (Blood)

Testing Laboratory

Auckland Te Toka Tumai | Auckland Hospital

Department

Immunology

Delphic Registration Code (Alpha Code)

AATP

Test Code (Numeric Code)

7958

Laboratory Handling

Phlebotomy

Serum

Transport

Ambient

Laboratory

LabPlus Immunochemistry

Test Adds Requirement

Samples are stored at -20°C for 1 month

Sample Stability

Received at 2-8°C, stored at 80°C until testing.

Associated Tests

• Alpha-1-antitrypsin
• C-reactive protein

Synonyms

AATP
AAT phenotype
A1AT phenotype
Antitrypsin phenotype

Turnaround Time

10 days

Test is batched every two weeks

Specimen Type

• Serum

Specimen Requirements

Tube/Container Type:

Preferred

• SST II (Gold Cap)

Acceptable

• Plain (Red Top)

Preferred Sample Volume (ml)

4

Minimum Sample Volume (ml)

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Plain(Microtainer)

Acceptable

• SST(Microtainer)

Preferred Sample Volume (ml)

0.5

Minimum Sample Volume (ml)

0.25

Pre-testing Requirements

Plasma alpha-1-antitrypsin (A1AT) and C reactive protein (CRP) concentrations measured on the same sample or within 24hrs are required for correct interpretation of this test. If either or both of these results are not supplied these will be measured at LabPLUS. Please also supply relevant clinical information or other laboratory information such as the indication for testing.

Aliquot Instructions

Sample Type

• Serum

Minimum Volume (ml)

1

Transport to Lab

Chilled (2 - 8 degrees Celsius)

Additional Referral/Aliquot Information

Plasma alpha-1-antitrypsin (A1AT) and C reactive protein (CRP) concentrations measured on the same sample or within 24hrs are required for correct interpretation of this test. If either or both of these results are not supplied these will be measured at LabPLUS. Please also supply relevant clinical information or other laboratory information such as serum electrophoresis findings if available.

Test Method

Isoelectric focusing (Sebia kit)

Limitations / Interference

A1AT phenotype may be difficult to interpret when there is a rare variant, in neonates with immature livers and following any treatment that may introduce a foreign A1AT enzyme (e.g. fresh frozen plasma infusion). Rarely the null variant, which produces no detectable A1AT, may be present but cannot be recognised. If A1AT activity is lower than expected for phenotype, this may be the case. Inflammation temporarily increases total A1AT activity and liver disease may lower it.

Uncertainty of Measurement

N/A, qualitative test.

Resources

• American Thoracic Society/European Respiratory Society statement: standards for the diagnosis and management of individuals with alpha-1 antitrypsin deficiency
• Prevalence and phenotype of subjects carrying rare variants in the Italian registry for alpha1-antitrypsin deficiency

Contact Information