Retinol-Binding Protein, Random, Urine
Use
Measurement of urinary retinol‑binding protein (a low‑molecular‑weight protein) is a useful aid in diagnosis and monitoring of proximal tubular dysfunction. Normally, RBP is filtered and reabsorbed by proximal tubular cells; elevated excretion indicates injury or dysfunction of these cells. Elevated excretion may reflect tubular damage from renal tubulointerstitial nephritis, nephrotoxic exposures, or coexisting tubular injury in glomerulopathies or vasculopathies. For spot collections, RBP concentration is corrected by creatinine to account for urine concentration variability.
Special Instructions
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen. All urine specimens should be centrifuged at ambient temperature prior to testing to remove turbidity or particles that may interfere with the nephelometric assay.
Limitations
Turbidity and particles (e.g., cells, crystals) in the specimen may interfere with the nephelometric assay. All specimens are evaluated for suitability; specimens failing criteria may be rejected. Reference intervals not established for patients under 18 years.
New York Approved
Methodology
Immunoassay (Nephelometry)
Biomarkers
LOINC Codes
- 96401-5
- 33782-4
- 96402-3
- 2161-8
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
5 mL
Minimum Volume
1 mL
Container
Plastic, 5‑mL tube
Collection Instructions
Collect a random urine specimen. No preservative.
Causes for Rejection
Turbidity or particles may interfere; specimens are evaluated for suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | 7 days |