Sign in →

Test Code OPTU Orthostatic Protein, Timed Collection, Urine

Reporting Name

Orthostatic Protein, U

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

Profile Information

Test ID Reporting Name Available Separately Always Performed
DOPTU Daytime Orthostatic Protein, U No Yes
NOPTU Nighttime Orthostatic Protein, U No Yes

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Urine


Advisory Information


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


Supplies: 2 Aliquot Tube, 5 mL (T465)

 

Daytime Collection

Container/Tube: Plastic, 5-mL tube (T465)

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 (T465)

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 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
Urine Refrigerated (preferred) 14 days
  Frozen  14 days
  Ambient  24 hours

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

Day(s) and Time(s) Performed

Monday through Sunday; Continuously

Test Classification

This test has been cleared or approved by the U.S. 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 In Process

 

Result ID Test Result Name Result LOINC Value
DPTU Daytime PTU In Process
NPTU Nighttime PTU In Process
DUR7 Nighttime collection duration 13362-9
DUR4 Daytime collection duration 13362-9
DVOL Day volume 19153-6
VL Night volume In Process
NPRO Night protein In Process
DPRO Day Protein In Process

Clinical Information

Orthostatic proteinuria refers to the development of increased proteinuria that develops only when the person is upright and resolves when recumbent or supine. This condition is usually seen in children, adolescents, or young adults, and accounts for the majority of cases of proteinuria in childhood.

 

Orthostatic proteinuria usually does not indicate significant underlying renal pathology, and is usually not associated with other urine abnormalities such as hypoalbuminemia, hematuria, red blood cell casts, fatty casts, etc. Orthostatic proteinuria typically resolves over time.

 

This test characterizes this condition by obtaining 2 urine collections within a 24-hour time frame, 1 collection obtained while the person is recumbent or supine, the other when upright.

Analytic Time

Same day/1 day

NY State Approved

Yes

Method Name

Turbidimetry

Forms

Orthostatic Protein Measurement 24-Hour Urine Patient Collection Instructions in Special Instructions