Alanine Aminotransferase (ALT)
Label Mnemonic: ALT
Epic code: LAB132
Downtime form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
6240 RCP
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
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
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.

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 
UV Testing
CPT Code:
See also:
Alanine Aminotransferase-Other, Body Fluid