Preferred Sample Type
Suitable Specimen Types
- Serum
- EDTA Plasma
- Li Hep Plasma
Specimen Transport
Not applicable
Sample Processing in Laboratory
No special transport requirements
Sample Preparation
Centrifuge. Store at 4oC
Turnaround Time
2 daysSample Stability
4 ºC (stable for 7 days at 4oC)
Alpha-1-Antitrypsin (A1AT or AAT)
General Information
Alpha-1-Antitrypsin is a glycoprotein synthesised in hepatocytes and is quantitatively the most important proteinase inhibitor (Pi) in serum and plasma. It specifically inactivates serine proteases (eg. Trypsin, chymotrypsin, collagenase, leucocyte elastase, plasmin and thrombin) with which it reversibly forms an enzyme-indicator complex.
Acute hereditary alpha-1-Antitrypsin deficiency is suspected in cases of neonatal hepatitis accompanied by progressive liver cirrhosis in early childhood. It is also suspected when severe pulmonary emphysema occurs in adults due to the prevalence of leucocyte elastase, which can lead to unrestrained proteolytic degradation of the pulmonary parenchymal cells.
Genetic variants of A1AT are characterised by their different electrophoretic mobilties i.e. M, S or Z. Z and S variants have decreased synthesis of A1AT. S forms produce 60-80% of normal and Z produces only 15% of normal.Normal range is age related.
Patient Preparation
None
Notes
No significant interference from haemolysis, icterus, or lipaemia. Elevated oestrogen levels (oral contraceptives, 3rd trimester of pregnancy) give rise to false positive results
Reference Range
Adult range 1.1 - 2.1 g/L.
Age related ranges are available by contacting the Immunology department.
Specifications
- EQA Scheme?: Yes
-
EQA Status:
UK NEQAS for Specific Proteins scheme