Alpha-1-antitrypsin (A1AT)
| Category | Biochemistry >> Proteins | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Test background |
Familial A1AT deficiency leads to predominantly unrestricted proliferation of neutrophil-mediated elastase in the tissues of the lung, causing extensive collateral damage and subsequent emphysema-like symptoms in adults. Alternatively, neonatal accumulation of dysfunctional A1AT in the liver causes the production of abnormal polymers that damage the surrounding tissues of the liver. |
||||||||||||||
| Clinical Indications |
Unexplained liver cirrhosis in juveniles (and rarely adults), suspected early-onset emphysema (juveniles/adults) or emphysema with or without family history. In results with an observed deficiency displayed on routine serum electrophoresis, A1AT will be routinely reflexed. Where results are low (typically ≤ 1.0 g/L) it is suggested that A1AT phenotyping is performed. Borderline low results (1.1 - 1.3 g/L) may indicate possible carrier status (the presence of a possible heterozygous deficiency allele e.g. S or Z). In these cases, although not usually risk factors themselves, a request for phenotyping may be appropriate as part of a further family study. |
||||||||||||||
| Reference range |
|
||||||||||||||
| Sample & container required | Serum (red top) or SST (gold top) | ||||||||||||||
| Sample volume | 0.5 mL | ||||||||||||||
| Transport storage | Stable at 2-8°C for 72 hours. Please freeze pending dispatch for analysis. Sample can be sent by first class post. |
||||||||||||||
| Turnaround time | 1 - 2 weeks | ||||||||||||||
| Notes | Grossly haemolysed samples are unsuitable for this assay. |