PTU - Clinical: Protein, Total, 24 Hour, Urine

Test Catalog

Test Name

Test ID: PTU    
Protein, Total, 24 Hour, Urine

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluation of renal disease


Screening for monoclonal gammopathy

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Protein in urine is normally composed of a combination of plasma-derived proteins that have been filtered by glomeruli and have not been reabsorbed by the proximal tubules and proteins secreted by renal tubules or other accessory glands.


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

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

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

-Overflow proteinuria: caused by increased plasma concentration of proteins (eg, multiple myeloma, myoglobinuria)

-Urinary tract inflammation or tumor

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.

<229 mg/24 hours

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

Reference value applies to 24-hour collection.

Interpretation Provides information to assist in interpretation of the test results

Total protein greater than 500 mg/24 hours should be evaluated by immunofixation to determine if a monoclonal immunoglobulin light chain is present, and if so, 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.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

False-proteinuria may be due to contamination of urine with menstrual blood, prostatic secretions, or semen.


The urinary protein concentration may rise to 300 mg/24 hours in healthy individuals after vigorous exercise.


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.


Samples should be collected before fluorescein is given or not collected until at least 24 hour later.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Rinehart BK, Terrone DA, Larmon JE, et al: A 12-hour urine collection accurately assesses proteinuria in hospitalized hypertensive gravida. J Perinatol 1999;19:556-558

2. Adelberg AM, Miller J, Doerzbacher M, Lambers DS: Correlation of quantitative protein measurements in 8-, 12-, and 24-hour urine samples for diagnosis of preeclampsia. Am J Obstet Gynecol 2001 Oct;185(4):804-807

3. Robinson RR: Isolated proteinuria in asymptomatic patients. Kidney Int 1980;18:395-406

4. Dube J, Girouard J, Leclerc P, et al: Problems with the estimation of urine protein by automated assays. Clin Biochem 2005;38(5):479-485

5. Koumantakis G, Wyndham, L: Fluorescein Interference with Urinary Creatinine and Protein Measurements. Clin Chem 1991;37(10):1799

Special Instructions and Forms Library of PDFs including pertinent information and consent forms, specimen collection and preparation information, test algorithms, and other information pertinent to test