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Test Code URCU Uric Acid, 24 Hour, Urine

Reporting Name

Uric Acid, U

Useful For

Assessment and management of patients with kidney stones, particularly uric acid stones

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Urine


Specimen Required


Container/Tube: Plastic, 5-mL tube (T465)

Specimen Volume: 5 mL

Collection Instructions:

1. Add 10 g of boric acid as preservative at start of collection.

2. Collect urine for 24 hours.

3. Mix well before taking 5-mL aliquot.

Additional Information:

1. 24-Hour volume is required.
2. See Urine Preservatives in Special Instructions for multiple collections.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 14 days
  Frozen  14 days

Reference Values

Diet-dependent: <750 mg/24 hours

The reference value is for a 24-hour collection. Specimens collected for other than a 24-hour time period are reported in unit of mg/dL for which reference values are not established.

Day(s) and Time(s) Performed

Monday through Sunday; Continuously

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

84560

LOINC Code Information

Test ID Test Order Name Order LOINC Value
URCU Uric Acid, U In Process

 

Result ID Test Result Name Result LOINC Value
UACID Uric Acid, U 3087-4
TM29 Collection Duration 13362-9
VL27 Urine Volume 3167-4
UACN1 Uric Acid Concentration 21587-1

Clinical Information

Uric acid is the end-product of purine metabolism. It is freely filtered by the glomeruli and most is reabsorbed by the tubules. There is also active tubular secretion.

 

Increased levels of uric acid in the urine usually accompany increased plasma uric acid levels unless there is a decreased excretion of uric acid by the kidneys. Urine uric acid levels reflect the amount of dietary purines and also endogenous nucleic acid breakdown.

Interpretation

Urinary uric acid excretion is elevated in a significant proportion of patients with uric acid stones.

 

Uric acid excretion can be either decreased or increased in response to a variety of pharmacologic agents.

 

Urine uric acid levels are elevated in states of uric acid overproduction such as in leukemia and polycythemia and after intake of food rich in nucleoproteins.

Clinical Reference

Newman DJ, Price CP: Renal function and nitrogen metabolites. In Textbook of Clinical Chemistry. Edited by NW Tietz. Philadelphia, WB Saunders Company, 1999, pp 1245-1250

Analytic Time

Same day/1 day

Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

 

Method Name

Uricase

Urine Preservative Collection Options

Ambient

No

Refrigerated

Yes

Frozen

Yes

6N HCl

No

50% Acetic Acid

No

Na2CO3

Yes

Toluene

Yes

6N HNO3

No

Boric Acid

Preferred

Thymol

Yes