Alanine Aminotransferase (ALT)

Label Mnemonic:	ALT
Epic code:	LAB132
Downtime form:	Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

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