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Test Code 12PU1 Protein, Total, 12 Hour, Urine


Necessary Information


12-Hour volume is required.



Specimen Required


Supplies: Sarstedt 5 mL Aliquot Tube (T914)

Container/Tube: Plastic, 5 mL tube

Specimen Volume: 4 mL

Collection Instructions:

1. Collect a 12-hour urine specimen. Specimens should be collected before fluorescein is given or not collected until at least 24 hour later.

2. No preservative.

3. Invert well before taking 4-mL aliquot.

4. Do not overfill aliquot tube, 4 mL at most.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.


Secondary ID

614042

Useful For

Evaluation of renal disease

 

Screening for monoclonal gammopathy

 

Screening for postural (orthostatic) proteinuria

 

In select clinical situations, collection of a 12-hour specimen may allow more rapid detection of proteinuria states (eg, screening pregnant patients for preeclampsia)

Method Name

Turbidimetry

Reporting Name

Protein, Total, 12 HR, U

Specimen Type

Urine

Specimen Minimum Volume

1 mL

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.

Clinical Information

Protein in urine normally consists of plasma proteins that have been filtered by glomeruli and not reabsorbed by the proximal tubule, and proteins secreted by renal tubules or other accessory glands.

 

Increased amounts of protein in the urine may be due to:

-Glomerular proteinuria: defects in permselectivity of the glomerular filtration barrier to plasma proteins (eg, glomerulonephritis or nephrotic syndrome)

-Tubular proteinuria: incomplete tubular reabsorption of proteins (eg, interstitial nephritis)

-Overflow proteinuria: increased plasma concentration of proteins that exceeds capacity for proximal tubular reabsorption (eg, multiple myeloma, myoglobinuria)

-Urinary tract inflammation or tumor

-Preeclampsia

-Orthostatic proteinuria

 

In pregnant women, a urinary protein excretion of more than 300 mg/24 hours is frequently cited as consistent with preeclampsia and 12-hour total protein excretion highly correlates with 24-hour values in this patient population.(1,2)

 

Orthostatic proteinuria is characterized by increased protein excretion in the upright position but normal levels when supine. This condition can be detected by comparing urine protein levels in a collection split between day and night (see OPTU / Orthostatic Protein, Timed Collection, Urine). Orthostatic proteinuria is common in childhood and adolescence but rare after 30 years of age.

Reference Values

<163 mg/12 hours (day or night collection)

Reference values have not been established for patients <18 years of age.

Interpretation

Total urine protein determined to be greater than 500 mg/24 hours should be evaluated by immunofixation to assess if there is a monoclonal immunoglobulin light chain and, if present, identify it as either kappa or lambda type.

 

Urinary protein levels may rise to 300 mg/24 hours in healthy individuals after vigorous exercise.

 

Low-grade proteinuria may be seen in inflammatory or neoplastic processes involving the urinary tract.

Method Description

The sample is pre-incubated 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 Gen.3. Roche Diagnostics; V13.0 11/2018)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test 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

LOINC Code Information

Test ID Test Order Name Order LOINC Value
12PU1 Protein, Total, 12 HR, U 26801-1

 

Result ID Test Result Name Result LOINC Value
TPU12 Protein, Total, 12 HR, U 26801-1
TM12A Collection Duration 13362-9
VL12A Urine Volume 13620-0

Urine Preservative Collection Options

Note: The addition of preservative or application of temperature controls must occur within 4 hours of completion of the collection.

Ambient

OK

Refrigerate

Preferred

Frozen

OK

50% Acetic Acid

No

Boric Acid

OK

Diazolidinyl Urea

OK

6M Hydrochloric Acid

No

6M Nitric Acid

No

Sodium Carbonate

No

Thymol

OK

Toluene

No

Forms

If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.

Day(s) Performed

Monday through Sunday