Alanine Aminotransferase (ALT)
Label Mnemonic: ALT
Epic Lab Code: LAB132
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; light green top or 1 Microtainer®
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
Males 0-41 U/L; Females 0-33 U/L Pediatric Normal Ranges: Age Male U/L Female U/L 1-30 days 1-25 2-25 31-365 days 4-35 3-30 1-3 years 5-30 5-30 4-6 years 5-20 5-25 7-9 years 5-25 5-25 10-18 years 5-30 5-20
Comments:
Adult reference ranges changed 11/26/2013. The upper limit of normal for alanine aminotransferase (ALT) reference ranges for adults is controversial with some authorities recommending limits as low as 30 U/L for males and 19 U/L for females. There is increased incidence of subclinical liver disease (e.g., early steatohepatitis) in patients with ALT values in the range of 31-41 U/L for males and 20-33 U/L for females. ALT values should always interpreted in conjunction with clinical history, physical examination findings, and, if applicable, data from other diagnostic tests.

References:
Schwimmer JB et al,. SAFETY Study: alanine aminotransferase cutoff values are set too high for reliable detection of pediatric chronic liver disease. Gastroenterology 2010; 138(4): 1357-1364.

This test is also performed in the Iowa River Landing (IRL) clinical laboratory (for specimens drawn at that site).
Test Limitations:
Criterion: Recovery within plus or minus 10% of initial value. Icterus: No significant interference up to an I index of 60 for conjugated and unconjugated bilirubin (approximate conjugated and unconjugated bilirubin concentration: 60 mg/dL). Hemolysis: No significant interference up to an H index of 200. RBC contamination may elevate results. Lipemia (Intralipid): No significant interference up to an L index of 250 (approximate triglycerides concentration: 500 mg/dL). There is poor correlation between turbidity and triglycerides concentration. Lipemia may cause absorbance flagging as a result of an absorbance increase.
Methodology:
UV Testing
CPT Code:
84460
 
See also:
Alanine Aminotransferase-Other, Body Fluid