uric acid in serum
Reference interval
- Male & Female: 2.5 - 8.5 mg/dL
Principle
The Kodak Ektachem Clinical Chemistry Slide (URIC) is a dry, multilayered analytical element coated on a clear polyester support.
A 10 uL drop of patient sample is deposited on the slide & is evenly distributed by the spreading layer into the underlying layers. Ascorbate oxidase in the scavenger layer catalyzes the conversion of endogenous ascorbic acid to products that will not interfere with subsequent reaction in the reagent layer. Uric acid from the sample migrates through the scavenger layer to the reagent layer, where it is oxidized in the presence of uricase to form allantoin & hydrogen peroxide. Hydrogen peroxide reacts with a leuco dye to produce a colored compound that is measured by reflectance spectrophotometry.
This analytical method for determining uric acid concentration is similar to those described in[4][5]. The assays differ in the choice of dye & , consequently, in the wavelength used to measure the density of resulting products
Uricase 2H2O + Uric Acid + O2 -------> Allantoin + H2O2 + CO2
Peroxidase
H2O2 + Leuco Dye ----------> Chromophoric Product
(colorless)
Clinical significance
- uric acid is the end products of purine metabolism
- excessive amounts of urate in plasma can result in urinary calculi (uric acid crystals)
Increases
- renal failure
- prerenal azotemia
- gout
- lead poisoning
- excessive cell destruction, e.g., following
- some endocrine disorders
- acidosis
- toxemia of pregnancy
- hereditary gout
- genetic variations in SLC2A9 influence the variance in serum uric acid concentrations
- glycogen storage disease type-1
- pharmaceutical agents:
- in vivo effects
- adrenocortical steroids, busulfan, ethacrynic acid, nitrogen mustard, purine analogues, pyrazinamide, quinethazone, thiazides, vincristine
- chemical interferences
- in vivo effects
Decreases
- pharmaceutical agents:
- low dietary intake of purines
- renal tubular defects
- xanthinuria
Specimen
Patient Preparation: No special patient preparation is required. For serum preparation collect whole blood & allow to clot according to manufacturer's instructions. Specimens are collected in a red top vacutainer by venipuncture & should be separated immediately from the cells after collection.
Minimum sample size 0.5 milliliter: with an optimum size of 1.0 milliliters or larger.
More general terms
Additional terms
Component of
References
- ↑ Kodak Ektachem 700 Analyzer Operator's Manual, Kodak Clinical Products, Rochester, New York.
- ↑ Kodak Ektachem Slide Package Inserts, Kodak Clinical Products Rochester, New York.
- ↑ Kodak Ektachem Training Manual, Kodak Clinical Products, Rochester, New York.
- ↑ 4.0 4.1 Kageyama, N.: A Direct Colorometric Determination of Uric acid in Serum & Urine with Uricase-Catalysts System. Clin, Chem. Acta 31:421, 1971.
- ↑ 5.0 5.1 Trivedi, R. C., Rabar, L. Berta, E. N. et al.: New Enzymatic method for Serum Uric Acid at 500 nm. Clinical Chemistry 24: 1908-1911, 1978.
- ↑ Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 12.
- ↑ 7.0 7.1 Journal Watch 25(14):114-15, 2005 Huang HY, Appel LJ, Choi MJ, Gelber AC, Charleston J, Norkus EP, Miller ER 3rd. The effects of vitamin C supplementation on serum concentrations of uric acid: results of a randomized controlled trial. Arthritis Rheum. 2005 Jun;52(6):1843-7. PMID: https://www.ncbi.nlm.nih.gov/pubmed/15934094
- ↑ Uric Acid Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0020026.jsp
- ↑ Mene P, Punzo G. Uric acid: bystander or culprit in hypertension and progressive renal disease? J Hypertens. 2008 Nov;26(11):2085-92 PMID: https://www.ncbi.nlm.nih.gov/pubmed/18854744