| 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 |
|
| STAT TAT |
N/A |
| 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 |
|
