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HelpTest Code OPTU Orthostatic Protein, Timed Collection, Urine
Reporting Name
Orthostatic Protein, UPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Diagnosis of orthostatic proteinuria
As a second-order test for additional characterization of proteinuria of less than 3 grams/24 hours, particularly in children or adolescents
Method Name
Turbidimetry
Ordering Guidance
This collection process requires 2 separate urine collections within a 24-hour period.
Collect specimen per instructions in Orthostatic Protein Measurement 24-Hour Urine: Collection Site Instructions (T546) in Special Instructions.
Necessary Information
This collection process requires 2 separate urine collections within a 24-hour period.
-Submit start and end times for collection and 16-hour volume (required).
-Submit start and end times for collection and 8-hour volume (required).
Specimen Required
Specimens should be collected before fluorescein is given or not collected until at least 24 hour later.
Supplies: 2 Sarstedt 5 mL Aliquot Tube (T914)
Daytime Collection
Container/Tube: Plastic, 5-mL tube
Specimen Volume: 4 mL
Collection Instructions:
1. Collect a 16-hour (daytime) urine specimen.
2. No preservative.
3. Invert well before taking 4-mL aliquot.
4. Do not over fill aliquot tube 4 mL at most.
5. Collect specimen per instructions in Orthostatic Protein Measurement 24-Hour Urine: Collection Site Instructions (T546) in Special Instructions.
Nighttime (Supine) Collection
Container/Tube: Plastic, 5-mL tube
Specimen Volume: 4 mL
Collection Instructions:
1. Collect an 8-hour (nighttime) urine specimen.
2. No preservative.
3. Invert well before taking 4-mL aliquot at most.
Specimen Type
UrineSpecimen Minimum Volume
1 mL from 16-hour (daytime) urine collection/1 mL from 8-hour (nighttime) urine collection
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| 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
Nighttime (supine) collection: <68 mg/8 hours
Reference values have not been established for patients <18 years of age.
Daytime collection: <197 mg/16 hours
Reference values have not been established for patients <18 years of age
Interpretation
A supine 8-hour urine protein excretion of less than 68 mg/8 hours together with either 1) an elevated upright (16-hour) excretion of greater than 197 mg/16 hours, or 2) a 24-hour urine protein excretion of greater than 228 mg/24 hours is considered consistent with orthostatic proteinuria.
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 to 4 daysTest Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
84156 x 2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| OPTU | Orthostatic Protein, U | 1755-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| DPTU | Total Protein, 16 HR, U | 49002-9 |
| NPTU | Total Protein, 8 HR, U | 50209-6 |
| DUR7 | Nighttime collection duration | 13362-9 |
| DUR4 | Daytime collection duration | 13362-9 |
| DVOL | Day volume | 19153-6 |
| VL | Night volume | 19153-6 |
| NPRO | Total Protein Conc, 8 HR, U | 35663-4 |
| DPRO | Total Protein Conc, 16 HR, U | 35663-4 |
Forms
1. Orthostatic Protein Measurement 24-Hour Urine: Patient Collection Instructions in Special Instructions
2. If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| DOPTU | Daytime Orthostatic Protein, U | No | Yes |
| NOPTU | Nighttime Orthostatic Protein, U | No | Yes |