Alanine Aminotransferase (ALT with P5P)

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:

Adult Male: 0-50 U/L

Adult Female: 0-35 U/L

Pediatric Ranges:

Age	ALT (U/L)
Up to 1 year	7-36
1-12 years	12-28
13-18 years (female)	10-25
13-18 years (male)	12-27

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:

Glick MR, Ryder KW, Jackson SA. Graphical Comparisons of Interferences in Clinical Chemistry Instrumentation. Clin Chem 1986;32:470-474.

Higgins V, Chan MK, Nieuwesteeg M, Hoffman BR, Bromberg IL, Gornall D, Randell E, Adeli K. Transference of CALIPER pediatric reference intervals to biochemical assays on the Roche cobas 6000 and the Roche Modular P. Clin Biochem. 2016 Jan;49(1-2):139-49. doi: 10.1016/j.clinbiochem.2015.08.018. Epub 2015 Aug 19. PMID: 26297116.

Test Limitations:

Hemolysis interferes due to ALT activity from erythrocytes and should be avoided. ALT will not be reported for specimens with severe enough hemolysis (100 – 500 mg/dL hemoglobin depending on ALT activity).

The assay is unaffected by icterus (bilirubin less than 60 mg/dL) and lipemia (Intralipid less than 150 mg/dL). Criterion: recovery within 10% of initial value.

Methodology:

Spectrophotometric with pyridoxal phosphate activation

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.