Alanine Aminotransferase (ALT)

Label Mnemonic:	ALT
Epic code:	LAB132
Order form:	Laboratory Requisition
Supply order:	Supply Order Form
Billing:	Billing Policies
CPT code:	84460

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.

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

Sample Processing:

Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells within 1 hour of collection. Send specimen in original tube. Do Not transfer to another tube.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.

Sample Storage:

Refrigerate.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).

Transport Instructions:

Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.

CPT Code:

84460