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Uric Acid, Serum / Plasma
|Test group||Uric acid|
|Performed by||Parnassus & Mt. Zion Chemistry|
|In House Availability||Test available 24 hours per day 7 days per week|
|Collection Instructions||Collection after overnight fast preferred.
For patients on rasburicase therapy, it is recommended that samples be sent to the laboratory on ice. Indicate "RASBURICASE THERAPY" prominently on the requisition.
It is recommended that this sample handling procedure for uric acid be followed for up to 4 days after the last dose of rasburicase is administered.
|Container type||Gold top or Light Green top (on ice if patient receiving Rubaricase)|
|Amount to Collect||1 mL blood Click here for Microdetermination info|
|Sample type||Serum or plasma|
|Preferred volume||0.5 mL serum or plasma|
|Min. Volume||0.2 mL serum or plasma Click here for Microdetermination info|
|Processing notes||If RASBURICASE THERAPY is indicated on the requisition the sample must be centrifuged cold and be kept refrigerated at 4C until testing. Deliver spun sample on ice to Chemistry asap.|
1. Pediatric reference ranges adopted from Soldin, Steven J. Pediatric Reference Intervals (method 3), 6th edition, AACC Press, 2007.
2. Normal range for adults was determined by testing 137 male and 129 female healthy blood donors at UCSF.
|Turn around times||4 hours|
|Additional information||Severe hyperbilirubinemia may artifactually decrease the result.
To convert mg/dL to mmol/L (SI units) multiply by 0.059
For patients on rasburicase therapy, it is recommended that samples be sent to the laboratory on ice and maintained at 4C until analysis to minimize in vitro degradation of uric acid that can occur due to sample transport (Lim E, Bennett P, Beilby J, Clinical Chemistry 2003;49:1417-1419). Uric acid samples in patients on rasburicase therapy should also be centrifuged cold and be kept refrigerated at 4C until testing. It is recommended that this sample handling procedure for uric acid be followed for up to 4 days after the last dose of rasburicase is administered.
According to some sources, "Although serum urate (SU) levels < 8 mg/dl are generally considered to be normal, serum levels > 6.8 mg/dl are above saturation level and may allow deposition of gouty crystals. A SU level of approximately 6.8 mg/dl is the concentration at which monosodium urate crystals begin to precipitate." Based on these considerations, some authorities recommend that that a normal SU should be considered below 6.8 mg/dL (Schlesinger et al .J Rheumatol 2009;36:1287–9). During an acute gouty attack, as many as 14% of patients may have a SU ≤ 6 mg/dlL and 32% may have SU of ≤ 8 mg/dL. Thus, a "normal" SU by either definition does not exclude an acute gouty attack.
|Last Updated||12/19/2012 4:34:25 PM|
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