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HelpOrder Code ORTHP Orthostatic Proteinuria, Random, Urine
Specimen Required
Patient Preparation: Specimens should be collected before fluorescein is given or not collected until at least 24 hour later.
Container/Tube: Plastic, 5-mL tube
Specimen Volume: 4 mL
Collection Instructions:
1. This is a nighttime (supine) collection.
2. Void immediately prior to lying down to sleep.
3. Collect an 8-hour (nighttime) urine specimen.
4. Upon awaking in the morning, the patient should immediately void into the specimen cup.
4. No preservative.
5. Invert well before taking 4-mL (maximum) aliquot.
Useful For
Diagnosis of orthostatic proteinuria
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| PRCON | Protein, Total, Random, U | No | Yes |
| RATO2 | Protein/Creatinine Ratio | No | Yes |
| CRETR | Creatinine, Random, U | No | Yes |
Method Name
PRCON: Turbidimetry
CRETR: Colorimetric
RATO2: Calculation
Reporting Name
Orthostatic Proteinuria, Random, USpecimen Type
UrineSpecimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 14 days |
| Frozen | 30 days | |
| Ambient | 24 hours |
Reject Due To
| All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Reference Values
PROTEIN/CREATININE RATIO:
≥18 years: <0.18 mg/mg creatinine
CREATININE:
≥18 years = 16-326 mg/dL
Reference values have not been established for patients younger than 18 years of age.
Method Description
Protein:
The sample is preincubated in an alkaline solution containing EDTA, which denatures the protein and eliminates interference from magnesium ions. Benzethonium chloride is then added, producing turbidity.(Package insert: Total Protein Urine/CSF. Roche Diagnostics; 05/2024)
Creatinine:
This enzymatic method is based on the conversion of creatinine with the aid of creatininase, creatinase, and sarcosine oxidase to form glycine, formaldehyde, and hydrogen peroxide. Catalyzed by peroxidase the liberated hydrogen peroxide reacts with 4-aminophenazone and HTIB (2,4,6-triiodo03-hydroxybenzoic acid) to form a quinone imine chromogen. The color intensity of the quinone imine chromogen formed is directly proportional to the creatinine concentration in the reaction mixture.(Package insert: Creatinine plus ver.2. Roche Diagnostics; 07/2024)
The final result uses a calculation to provide the total protein per creatinine ratio. This calculation is performed by the laboratory information system, SCC Soft.
Day(s) Performed
Monday through Sunday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
CRETR- 82570
PRCON- 84156
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| ORTHP | Orthostatic Proteinuria, Random, U | 87434-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CRETR | Creatinine, Random, U | 2161-8 |
| PRCON | Protein, Total, Random, U | 2888-6 |
| RATO2 | Protein/Creatinine Ratio | 2890-2 |