Uric Acid

CPT: 84550
Print Share

Test Details

Synonyms

  • UA
  • Urate

Use

Uric acid measurements are useful in the diagnosis and treatment of gout, renal failure, and a variety of other disorders including leukemia, psoriasis, starvation, and other wasting conditions. Patients receiving cytotoxic drugs may be monitored with uric acid measurements. Only a minority of individuals with hyperuricemia develop gout. An increased uric acid level does not necessarily translate to a diagnosis of gout.3 The therapeutic goal for uric acid-lowering therapy is to promote crystal dissolution and prevent crystal formation. This is achieved by maintaining a uric acid level <6 mg/dL.2

Elevated uric acid: Elevations of uric acid occur with increased purine synthesis, inherited metabolic disorders, excess dietary purine intake, increased nucleic acid turnover, malignancy, cytotoxic drugs, decreased excretion due to chronic renal failure, and increased renal reabsorption.

Drugs: Drugs causing increased uric acid concentration include diuretics, pyrazinamide, ethambutol, and nicotinic acid.3

Endocrine: Hypothyroidism, hypoparathyroidism, hyperparathyroidism, pseudohypoparathyroidism, diabetes insipidus of nephrogenic type, and Addison disease can cause uric acid elevation. Lead poisoning from paint, batteries, and moonshine can cause elevated uric acid.4 Toxemia of pregnancy, diet, weight loss, fasting, or starvation can elevate uric acid levels.5

Decreased uric acid: Drugs bearing a relationship to low serum uric acid levels include aspirin (high doses), x-ray contrast agents, glyceryl guaiacolate, allopurinol corticosteroids, and probenecid.6 Massive doses of vitamin C increase urine uric acid secretion, lowering serum uric acid.4 Poor dietary intake of purines and protein can decrease serum uric acid. Diabetes, Fanconi syndrome, Wilson's disease, cystinosis, galactosemia, hypophosphatemia, heavy metal poisoning, malignant neoplasms, hypereosinophilic syndrome, and Xanthinuria (deficiency of xanthine oxidase) can lower serum uric acid.4,6,7 Hypouricemia is reported with acute intermittent porphyria and severe liver disease (especially obstructive biliary disease).8 Isolated defects in the tubular transport of uric acid have been associated with increased renal clearance of urate, hypouricemia, hypercalciuria, and decreased bone density.9

Methodology

Uricase

Reference Interval

• Male:1

− 0 to 1 month: 3.3−8.4 mg/dL

− 1 to 12 months: 1.9−8.1 mg/dL

− 1 to 12 years: 1.9−5.8 mg/dL

− 12 to 18 years: 3.4−7.8 mg/dL

− 18 years and older: 3.7−8.6 mg/dL

• Female:

− 0 to 1 month: 2.4−6.5 mg/dL

− 1 to 12 months: 2.1−6.5 mg/dL

− 1 to 12 years: 2.0−5.8 mg/dL

− 12 to 18 years: 2.4−6.3 mg/dL

− 18 years and older: 2.5−7.1 mg/dL

Therapeutic target for gout patients: <6.02

Additional Information

Drug effects have been summarized.10

Specimen Requirements

Specimen

Serum (preferred) or plasma

Volume

1 mL

Minimum Volume

0.5 mL

Container

Red-top tube, gel-barrier tube, green-top (heparin) tube, or lavender-top (EDTA) tube

Patient Preparation

At least four-hour fast preferred

Collection

Separate serum or plasma from cells within 45 minutes of collection.

Storage Instructions

Maintain specimen at room temperature.1

Stability Requirements

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3

Causes for Rejection

Improper labeling

Clinical Information

Footnotes

1. LabCorp internal studies
2. Zhang W, Doherty M, Bardin T, Suárez DH, Aristimuno GG. EULAR evidence based recommendations for gout. Part II: Management. Report of a task force of the EULAR Standing Committee for International Clinical Studies Including Therapeutics (ESCISIT). Ann Rheum Dis. 2006 Oct; 65(10):1301-1311. 16707532
3. Messerli FH, Frohlich ED, Dreslinski GR, Suárez DH, Aristimuno GG. Serum uric acid in essential hypertension: An indicator of renal vascular involvement. Ann Intern Med. 1980 Dec; 93(6):817-821. 7447188
4. Cameron JS, Simmonds HA. Uric acid, gout and the kidney. J Clin Pathol. 1981 Nov; 34(11):1245-1254. 7320221
5. Lin HY, Rocker LL, McQuillan MA, Schmaltz S, Palella TD, Fox IH. Cyclosporine-induced hyperuricemia and gout. N Engl J Med. 1989 Aug 3; 321(5):287-292. 2664517
6. Lugassy G, Michaeli J. Hypouricemia in the hypereosinophilic syndrome. Response to treatment. JAMA. 1983 Aug 19; 250(7):937-938. 6864977
7. Pollard A. Disorders of purine and pyrimidine metabolism. In: Gornall AG, ed. Applied Biochemistry of Clinical Disorders. Hagerstown, Md: Harper & Row Publishers;1980:335-344. 16707533
8. Ramsdell CM, Kelley WN. The clinical significance of hypouricemia. Ann Intern Med. 1973 Feb; 78(2):239-242. 4683752
9. Steele TH. Hypouricemia. N Engl J Med. 1979 Sep 6; 301(10):549-550. 460310
10. Zhiri A, Jouanel P. Urates. In: Siest G, Galteau MM, eds. Drug Effects on Laboratory Test Results. Analytical Interferences and Pharmacological Effects. Littleton, Mass: PSG Publishing Co;1988:423-438. 3606290

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
001057 Uric Acid, Serum 3084-1 001057 Uric Acid, Serum mg/dL 3084-1
Reflex Table for Uric Acid, Serum
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 001061 Please Note: 001061 Please Note: N/A

For Providers

Please login to order a test.

 

© 2017  Laboratory Corporation of America® Holdings and Lexi-Comp Inc. All Rights Reserved.

CPT Statement/Profile Statement

The LOINC® codes are copyright © 1994-2017, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. Permission is granted in perpetuity, without payment of license fees or royalties, to use, copy, or distribute the LOINC® codes for any commercial or non-commercial purpose, subject to the terms under the license agreement found at https://loinc.org/license/. Additional information regarding LOINC® codes can be found at LOINC.org, including the LOINC Manual, which can be downloaded at LOINC.org/downloads/files/LOINCManual.pdf