Test ID: OPTU
Orthostatic Protein, Urine
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Diagnosis of orthostatic proteinuria
As a second-order test for further characterization of proteinuria <3 grams/24 hours, particularly in children or adolescents
Profile Information A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| DOPTU | Daytime Orthostatic Protein, U | No | Yes |
| NOPTU | Nighttime Orthostatic Protein, U | No | Yes |
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Dye Binding (Pyrogallol Red)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Postural Proteinuria Assessment
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
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 (Supply T546) in Special Instructions.
Forms: Orthostatic Protein Measurement 24-Hour Urine Patient Collection Instructions in Special Instructions
Daytime Collection
Container/Tube: Plastic, 6-mL tube (Supply T465)
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a 16-hour (daytime) urine specimen.
2. No preservative.
3. Mix well before taking 5-mL aliquot.
Additional Information: Starting and ending times of daytime collection and 16-hour volume are required.
Nighttime (Supine) Collection
Container/Tube: Plastic, 6-mL tube (Supply T465)
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a 8-hour (nighttime) urine specimen.
2. No preservative.
3. Mix well before taking 5-mL aliquot.
Additional Information: Starting and ending times of nighttime collection and 8-hour volume are required.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
1 mL from 8-hour (nighttime) urine collection
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 7 days |
| Ambient | 7 days | |
| Frozen | 7 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Nighttime (supine) collection: <50 mg/specimen
Daytime collection
Males: 0-150 mg/specimen
Females: 27-93 mg/specimen
Interpretation Provides information to assist in interpretation of the test results
Supine urine protein excretion <50 mg/specimen with an elevated upright or 24-hour urine collection (>150 mg for males, >93 mg for females) is considered consistent with orthostatic proteinuria.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
It is not unusual for urine protein excretion derived from supine collections to be somewhat lower than protein excretion derived from upright collections. However, orthostatic or postural proteinuria is characterized by a supine excretion rate of <50 mg/8 hrs.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Dodge WF, West EF, Smith EH, Harvey B: Proteinuria and hematuria in school children: Epidemiology and early natural history. J Pediatr 1976;88:327
2. Hogg RJ, Portman RJ, Milliner D, et al: Evaluation and management of proteinuria and nephritic syndrome in children. Pediatrics 2000;105:1242
3. Addis T: Prognosis in postural (orthostatic proteinuria). Forty to fifty-year follow-up of six patients after diagnosis. N Engl J Med 1981;305:618
Method Description Describes how the test is performed and provides a method-specific reference
The pyrogallol red (PR) dye is combined with molybdenum acid (MO VI), forming a red complex with maximum absorption at 470 nm. When this complex is combined with protein under acidic conditions, its maximum absorption is shifted to a longer wavelength and develops a blue-purple color with a maximum at 604 nm. The concentration of protein in the specimen is equivalent to the absorbance of the dye urine mixture measured at 600 nm.(Package insert: Wako)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday; 7 a.m.-4:30 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
84156 x 2
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| 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 | In Process |
| VL | Night volume | In Process |
| NPRO | Night protein | In Process |
| DPRO | Day Protein | In Process |
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