{"id":"alpha-1-antitrypsin","name":"Alpha-1 Antitrypsin (AAT) Level","shortName":"Alpha-1 antitrypsin","aliases":["Alpha-1 Antitrypsin","A1AT","AAT","Alpha-1 Antitrypsin, Serum","Alpha-1 Antitrypsin Level","Alpha-1-Antitrypsin, Quant","Alpha-1-Antitrypsin, Quantitative","Alpha-1-Antitrypsin","Alpha 1 Antitrypsin","A1-Antitrypsin","Anti-Alpha-1-Trypsin","Alpha1-Antitrypsin","Serum AAT","AAT Level","Alpha-1 Antitrypsin, Quantitative, Serum"],"abbreviations":["AAT","A1AT"],"loinc":[{"code":"1825-9","primary":true},{"code":"6771-0","primary":false},{"code":"76481-1","primary":false}],"specimen":"serum-or-plasma","units":[{"ucum":"mg/dL","display":"mg/dL"},{"ucum":"g/L","display":"g/L"}],"referenceRanges":[{"population":"18+","low":90,"high":200,"unit":"mg/dL","unitDisplay":"mg/dL","note":"ARUP (effective 2014) and Labcorp's 2016 sample report both print 90–200 mg/dL (0.90–2.00 g/L). Labcorp's current test page lists narrower, age- and sex-specific ranges instead: 95–164 mg/dL for males and 100–188 mg/dL for females aged 13 to 40, and 101–187 mg/dL above 40. Older reference lists give 150–350 mg/dL (1.5–3.5 g/L). Assay calibration differs between methods and over time, so use the range printed on your own report first.","sources":[{"title":"Alpha-1-Antitrypsin, Serum (test 001982), sample report","url":"https://files.labcorp.com/testmenu-d8/sample_reports/001982.pdf","publisher":"Labcorp"},{"title":"Alpha-1-Antitrypsin, Serum (test 001982)","url":"https://www.labcorp.com/tests/001982","publisher":"Labcorp"},{"title":"Alpha-1-Antitrypsin (test 0050001)","url":"https://ltd.aruplab.com/Tests/Pub/0050001","publisher":"ARUP Laboratories"},{"title":"Hereditary alpha-1-antitrypsin deficiency and its clinical consequences","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2441617/","publisher":"Orphanet Journal of Rare Diseases","year":2008}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"A protein made by the liver that helps protect the lungs. A low level can be a first clue to alpha-1 antitrypsin deficiency, an inherited condition.","url":"https://bloodtesttracker.com/markers/alpha-1-antitrypsin","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}