Cystine, Random Urine with Creatinine

Message
For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.


Test Code
CYSTNR


CPT Codes
86160, 82131, 82570

Includes
Creatinine


Preferred Specimen
1.8 mL unpreserved random urine collected in a sterile screw-cap container


Minimum Volume
0.6 mL


Other Acceptable Specimens
Unpreserved Catheterized urine or First void clean-catch urine, or random clean-catch urine collected in a sterile screw-cap container


Instructions
Do not use preservatives. Do not thaw.
Urine with a pH less than 2.0 will be rejected.
Patient age is required for correct reference range.


Transport Temperature
Frozen


Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 60 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Received room temperature • Received refrigerated • pH <2.0


Methodology
Liquid Chromatography/Mass Spectrometry (LC/MS)

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Tuesday, Thursday Morning
Report available: 5 Days


Reference Range
Cystine
Pediatric (<18 Years) 3.2-12.6 mmol/mol creat
Adult 3.4-16.4 mmol/mol creat

Creatinine, Random Urine
0-6 Months 0.18-2.48 mmol/L
7-11 Months   0.18-2.74 mmol/L
1-2 Years 0.18-9.72 mmol/L
3-8 Years 0.18-11.49 mmol/L
9-12 Years 0.18-14.14 mmol/L
>12 Years 1.77-23.31 mmol/L


Clinical Significance
Cystinuria is an autosomal recessive disease in which dibasic amino acids, including cystine, are excreted in excess.


Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042



Last Updated: November 29, 2021


The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.