Determining glomerular filtration rate in urine specimens
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Urine
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Container/Tube: Plastic vial
Specimen Volume: 5 mL
Collection Instructions: Collect a timed urine specimen.
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
0.5 mL
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 7 days | |
Frozen | 35 days |
Determining glomerular filtration rate in urine specimens
The assessment of glomerular filtration rate (GFR) is an important parameter of renal function utilized by clinicians in the care of patients with varying renal diseases, and for clinical research when precise assessment of renal function is necessary. The GFR is the sum of all the filtration rates of the individual nephrons within the kidney and, as such, reflects the number of functioning nephrons.
Urine concentrations of iohexol can be used for measurement of GFR following a subcutaneous injection of iohexol (plasma disappearance), or during a continuous infusion of iohexol when used in conjunction with plasma iohexol determinations (HEXP / Iohexol, Plasma). The results can be used to determine the clearance of iohexol, which is a measure of GFR.
Not applicable
Low glomerular filtration rate (GFR) values indicate abnormal renal function, which may be either reversible/transient or irreversible/permanent. GFR tends to decline with age.
1. Brown SC, O'Reilly PH: Iohexol clearance for the determination of glomerular filtration rate in clinical practice: evidence for a new gold standard. J Urol 1991;146:675-679
2. Gaspari F, Perico N, Ruggenenti P, et al: Plasma clearance of nonradioactive iohexol as a measure of glomerular filtration rate. J Am Soc Nephrol 1995;6:257-263
3. Schwartz GJ, Abraham AG, Furth SL, et al: Optimizing iohexol plasma disappearance curves to measure the glomerular filtration rate in children with chronic kidney disease. Kidney Int 2010;77:65-71
Monday through Friday
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
82542
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
HEXU | Iohexol, U | 93973-6 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
61712 | Iohexol, U | 93973-6 |