Tubular Reabsorption of Phosphorus, Random Urine and Serum
Use
This test is useful for assessing renal reabsorption of phosphorus in various pathological conditions associated with hypophosphatemia, such as hypophosphatemic rickets, tumor-induced osteomalacia, and tumoral calcinosis. It also aids in adjusting phosphate replacement therapy in severe deficiency states and monitoring renal tubular recovery from acquired Fanconi syndrome. Additionally, the test evaluates the glomerular filtration of phosphorus, providing insights into the renal phosphate threshold and defect in phosphate reabsorption.
Special Instructions
If not ordering electronically, complete and send a Renal Diagnostics Test Request form with the specimen.
Limitations
The test interpretation depends on the clinical situation and should be used in conjunction with serum phosphorus concentration. A reduced tubular reabsorption of phosphate in the presence of hypophosphatemia indicates a renal defect in phosphate reabsorption. Although direct measurements of parathyroid hormone have replaced much of the utility of TmP/GFR measurements, it remains useful for assessing renal reabsorption of phosphorus in various pathological conditions associated with hypophosphatemia.
New York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 50057-9
- 103542-7
- 2160-0
- 2161-8
- 2777-1
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
Not provided
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial. Label specimen as serum.
Patient Preparation
Fasting: 12 hours, required
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |
| Frozen | 90 days |