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HelpTest ID 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.
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Secondary ID
614042Useful 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)
Special Instructions
Method Name
Turbidimetry
Reporting Name
Protein, Total, 12 HR, 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 |
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.
Cautions
False proteinuria may be due to contamination of urine with menstrual blood, prostatic secretions, or semen.
After vigorous exercise, the urinary protein concentration may rise to 300 mg/24 hours in healthy individuals.
Normal newborn infants may have higher excretion of protein in urine during the first 3 days of life.
The presence of hemoglobin elevates protein concentration.
Protein electrophoresis and immunofixation may be required to characterize and interpret the proteinuria.
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 dayPerforming 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