Assessment and management of patients with kidney
Uricase
Urine
X-ray dyes and contrast media will affect test results.
-If a kidney X-ray with dye or computerized tomography (CT) scan with contrast has been performed, patient should wait a minimum of 1 day before starting collection.
-If a cholangiography (bile duct X-ray) has performed, patient should wait 7 days before starting collection.
-Urine must be collected before tablets have been taken for gallbladder X-ray, otherwise patient should wait 7 days before starting collection.
24-Hour volume (in milliliters) is required.
Question ID | Description | Answers |
---|---|---|
TM29 | Collection Duration | |
VL27 | Urine Volume |
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Collection Container/Tube: 24-Hour graduated urine container with no metal cap or glued insert
Submission Container/Tube: Plastic, 5 mL tube or a clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 5 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Refrigerate specimen within 4 hours of completion of 24-hour collection.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Note: The addition of preservative or application of temperature controls must occur within 4 hours of completion of the collection.
Ambient | No |
Refrigerate | OK |
Frozen | OK |
50% Acetic Acid | No |
Boric Acid | Preferred |
Diazolidinyl Urea | OK |
6M Hydrochloric Acid | No |
6M Nitric Acid | No |
Sodium Carbonate | OK |
Thymol | OK |
Toluene | No |
1 mL
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 14 days | |
Frozen | 30 days | ||
Ambient | 7 days |
Assessment and management of patients with kidney
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 endogenous nucleic acid breakdown.
Males > or =18 years old: 200-1,000 mg/24 hours
Females > or =18 years old: 250-750 mg/24 hours
Reference values have not been established for patients who are less than 18 years of age.
The reference value is for a 24-hour collection.
Urinary uric acid excretion is elevated in a significant proportion
Uric acid excretion can be either decreased or increased in
Urine uric acid levels are elevated in states of uric acid overproduction
High levels of bilirubin and ascorbic acid may interfere with measurement.
1. Lamb EJ, Jones GRD: Kidney function tests. Rifai N, Horvath AR, Wittwer CT, eds: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:500-503
2. Newman DJ, Price CP: Renal function and nitrogen metabolites. In: Tietz NW, ed. Textbook of Clinical Chemistry. WB Saunders Company; 1999:1245-1250
Uric acid is oxidized by the specific enzyme uricase to form allantoin and peroxide. Peroxide reacts in the presence of peroxidase and a color reagent to form a red color, the intensity of which is proportional to the uric acid concentration.(Package insert: Roche Uric Acid Plus. Roche Diagnostics; V13.0 05/2019)
Monday through Sunday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
84560
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
URCU | Uric Acid, 24 HR, U | 3087-4 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
UACID | Uric Acid, 24 HR, U | 3087-4 |
TM29 | Collection Duration | 13362-9 |
VL27 | Urine Volume | 3167-4 |
UACN1 | Uric Acid Concentration | 21587-1 |