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 Field Name  Data Description
Test Name  Uric Acid, 24 hour Urine
Code  Uric Acid 24Hr Urine.
CPT Code  84560
Last Modified  7/10/2018 9:19:00 AM
Test Name  U Uric Acd.
Synonyms  uacid,
Patient Preparation  Standard diet 24 hours prior to collection.
Spec. Requirements  Urine 24 Hour
Tube  24 hour plastic urine container
Collection Volume  10.0 mL aliquot of entire collection
Storage  Refrigerate, Ambient or Frozen 14 days
Routine TAT  
Days Test Performed  
Performed by BHS  None
See Availability  
Reference Lab  LabCorp of America
Reference Lab Code  003418 Uric Acid, 24 hr Urine
Clinical Use  Look for hyperuricosuria in patients with renal calculus formation. Identification of overexcretors re: risks of stone formation, identification of genetic defects, influence of overexcretion on therapy of gout. Uric acid nephrolithiasis occurs in primary gout or in secondary hyperuricemia (eg, malignant diseases). Uric acid nephrolithiasis may complicate ulcerative colitis, Crohn disease, and surgical jejunoileal bypass. Most subjects with uric acid stones do not have gout. Evaluate uric acid metabolism in gout. Even mild renal failure decreases uric acid excretion. Uric acid excretion is decreased with hypertension. A young patient with acute gouty arthritis, uric acid stones, and any patient who excretes >1000 mg uric acid/24 hours, should be evaluated for HPRT deficiency. The uric acid:creatinine ratio has been used as a test for Lesch-Nyhan syndrome (HPRTase deficiency). Normal control patients 0.21-0.59; partial enzyme deficient group 0.62-2.00; complete enzyme deficiency 1.98-5.35. The ratio of uric acid:creatinine in morning samples of urine has been used as a test for detection of the Lesch-Nyhan syndrome, which is associated with virtually complete absence of activity of the enzyme hypoxanthine-guanine phosphoribosyltransferase. This ratio has also been applied to 24-hour urine samples from adult patients with gout for detection of partial deficiency of the same enzyme. The uric acid:creatinine ratio in the urine of normal control patients is reported to range from 0.21-0.59. Patients with gout exhibit ratios of 0.15-0.73, whereas those patients with hyperuricemia associated with another disorder such as leukemia or glycogen-storage disease have ratios of 0.25-1.77. The ratio is 0.27-0.58 for patients with nongouty arthritis. Patients with complete hypoxanthine-guanine phosphoribosyltransferase deficiency are reported to have urinary uric acid:creatinine ratios of 1.98-5.35, as compared to 0.62-2.00 for patients with gout accompanied by partial enzyme deficiency. The ratio of uric acid:creatinine concentration on a random urine specimen has also been shown to be >1.0 in patients with acute renal failure secondary to acute uric acid nephropathy, but <1.0 in patients with acute renal failure resulting from other causes.
Reference Range  
Critical Value  
Testing Sample Type  Urine 24 Hour
Min Lab Testing Volume  1.0 mL
Special Handling  Collection: Mix well,State urine volume on the request form.
Lab Notes  
Methodology  Uricase
Limitations  Causes for Rejection:Improperly labeled specimen; use of preservative; pH<6

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