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Alpha-1 Antitrypsin
Abbreviation: AAT
Panel: Liver Function Tests · All liver function tests
Typical adult reference range
| Conventional units | 100–200 mg/dL |
| SI units | 20–38 µmol/L |
Ranges vary between laboratories and methods — compare your result with the range printed on your own report.
What a high or low result can mean
High alpha-1 antitrypsin: high values can be seen as an acute-phase response to inflammation.
Low alpha-1 antitrypsin: low values may occur in inherited alpha-1 antitrypsin deficiency, which can affect liver and lungs.
These are associations, not a diagnosis: the same result can have several causes, and your clinician interprets it with the rest of your results and history.
Related tests — Liver Function Tests
Please note: Reference ranges vary between laboratories, and between the methods and instruments they use — the range printed on your own report is the one your result should be compared with. A result outside the range is not by itself a diagnosis, and a result inside it does not rule out illness. These pages are an educational summary, not medical advice: always discuss your results with the clinician who ordered them, who can interpret them in the context of your health and history.