Uric Acid
Label Mnemonic: URIC
Epic code: LAB141
Order form: Laboratory Requisition
Supply order: Supply Order Form
Billing: Billing Policies
CPT code: 84550
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 whole blood in light green top tube or ONE Microtainer® for pediatric patients.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
     Age                   Male              Female
0 to <15 days        2.7 – 12.6 mg/dL   2.7 – 12.6 mg/dL
15 days to <1 year   1.5 – 6.2 mg/dL    1.5 – 6.2 mg/dL
1 to <12 years       1.7 – 4.7 mg/dL    1.7 – 4.7 mg/dL
12 to <19 years      2.5 – 7.5 mg/dL    2.5 – 5.7 mg/dL
Adults >= 19 years   3.4 – 7.0 mg/dL    2.4 – 5.7 mg/dL

Pediatric reference intervals updated on 6/15/2021

Colantonio DA, Kyriakopoulou L, Chan MK, Daly CH, Brinc D, Venner AA, Pasic MD, Armbruster D, Adeli K. Closing the gaps in pediatric laboratory reference intervals: a CALIPER database of 40 biochemical markers in a healthy and multiethnic population of children. Clin Chem. 2012 May;58(5):854-68. doi: 10.1373/clinchem.2011.177741. Epub 2012 Feb 27. PMID: 22371482.

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. Erratum in: Clin Biochem. 2016 Oct;49(15):1210. PMID: 26297116.
Comments:
Refer to BD Microtainer® Tubes product sheet for detailed sample collection instructions.

For patients who have received rasburicase (Elitek) within 48 hours of anticipated blood draw, "Uric Acid (on ice-Elitek)" (Epic #LAB870) should be ordered instead to avoid falsely low uric acid levels due to breakdown of uric acid by the uricase enzyme in the blood tube. See additional information listed in the links below.
Test Limitations:
Criterion: Recovery within plus or minus 10% of initial values

Plasma
Icterus: No significant interference up to an I index of 40 
(approximate conjugated and unconjugated bilirubin concentration 40 
mg/dL or 684 umol/l).

Hemolysis: No significant interference up to an H index of 1000 
(approximate hemoglobin concentration: 1000 mg/dL or 621 umol/l).

Lipemia (Intralipid): No significant interference up to an L index of 
1500.

There is poor correlation between turbidity and triglycerides 
concentration.

Ascorbic acid less than 3 mg/dL does not interfere.

Of the drugs tested in vitro, o-methyldopa, desferoxamine and calcium 
dobesilate (e.g. Dexium) cause interference at therapeutic 
concentrations (uric acid level artificially low).

Uricase reacts specifically with uric acid. Other purine derivatives 
can inhibit the uric acid reaction.

Reference:
Glick MR, Ryder KW, Jackson SA. Graphical Comparisons of Interferences 
in Clinical Chemistry Instrumentation. Clin Chem 1986;32:470-474.
Methodology:
Enzymatic Colorimetric
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:
84550
 
See also:
Uric Acid-Other, Body Fluid