Alpha-1-Antitrypsin (AAT)

Department of Immunology

Notes

• Alpha 1 antitrypsin levels are reduced in hereditary α1-antitrypsin deficiency.
• Alpha 1 antitrypsin testing should be considered in early-onset emphysema, emphysema without risk factors (e.g. smoking, occupational exposure) or where there is a strong family history of lung or liver disease.
• If the result is below the reference range phenotyping will also be performed, which is referred to North Bristol NHS Trust. Patients with ZZ, SZ, SS, MZ phenotypes are at risk of lung (emphysema) or liver disease (cirrhosis), although this varies significantly depending on the phenotype.
• Alpha 1 antitrypsin is an acute phase reactant and therefore levels may be higher than expected during acute infection/inflammation regardless of phenotype.

Sample Requirements

Clotted blood. (No patient preparation or special handling required)

Adult

5ml Gold-top SST tube or 3.5ml Rust-top gel tube (Trust users only)

Paediatric

1ml Serum Sample

Turnaround Times

AAT Quantitation 1 week

AAT Phenotyping 21 days

Time Limit for Add-ons

3 days

Reference Ranges

0.9 - 2.0g/L