Alpha-1-Antitrypsin Quantitation
Label Mnemonic: A1AT
Epic Lab Code: LAB927
Downtime Form: A-1a General Laboratory Requisition
Chemistry
6240 RCP
356-3527
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood in light green top tube or ONE Microtainer®
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
90-200 mg/dL
A1AT is an acute phase reactant, therefore any inflammatory process may result in transient elevations of the patient's A-1-AT level.
Test Limitations:
Criterion: Recovery within plus or minus 10% of initial values. Icterus: No significant interference up to an I index of 60 (approximate conjugated and unconjugated bilirubin concentration: 60 mg/dL). Hemolysis: No significant interference up to an H index of 1000 (approximate hemoglobin concentration: 1000 mg/dL). Lipemia (Intralipid): No significant interference up to an L index of 350 (approximate triglycerides concentration: 700 mg/dL). There is poor correlation between turbidity and triglycerides concentration. Rheumatoid factors less than 100 IU/mL do not interfere. No high dose hook effect is seen up to an alpha 1-antitrypsin concentration of 1200 mg/dL. Elevated estrogen levels (oral contraceptives; third trimester of pregnancy) give rise to false positive results. CRP and haptoglobin should therefore also be determined.* *Laurell CB, Kullander S, Thorell J. Effect of administration of a combined estrogen-progestin contraceptive on the level of individual plasma proteins. Scand J Lab Invest 1968;21:337-343.
Methodology:
Immunoturbidimetric
CPT Code:
82103