Protein, Urine

Protein, Urine: Total Quantitativeand Fractions

Synonym/acronym: None.

Common use

To assess for the presence of protein in the urine toward diagnosing disorders affecting the kidneys and urinary tract, such as cancer, infection, and pre-eclampsia.

Specimen

Urine (5 mL) from an unpreserved random or timed specimen collected in a clean plastic collection container.

Normal findings

(Method: Spectrophotometry for total protein, electrophoresis for protein fractions)
Conventional UnitsSI Units (Conventional Units × 0.001)
Total protein30–150 mg/24 hr0.03–0.15 g/24 hr
Electrophoresis for fractionation is qualitative: No monoclonal gammopathy detected. (Urine protein electrophoresis should be ordered along with serum protein electrophoresis.)

Description

Most proteins, with the exception of the immunoglobulins, are synthesized and catabolized in the liver, where they are broken down into amino acids. The amino acids are converted to ammonia and ketoacids. Ammonia is converted to urea via the urea cycle. Urea is excreted in the urine.

This procedure is contraindicated for

    N/A

Indications

  • Assist in the detection of Bence Jones proteins (light chains)
  • Assist in the diagnosis of myeloma, Waldenström’s macroglobulinemia, lymphoma, and amyloidosis
  • Evaluate kidney function

Potential diagnosis

Increased in

  • Diabetic nephropathy (related to disease involving renal glomeruli, which increases permeability of protein)
  • Fanconi’s syndrome (related to abnormal protein deposits in the kidney, which can cause Fanconi’s syndrome)
  • Heavy metal poisoning (related to disease involving renal glomeruli, which increases permeability of protein)
  • Malignancies of the urinary tract (tumors secrete protein into the urine)
  • Monoclonal gammopathies (evidenced by large amounts of Bence Jones protein light chains excreted in the urine)
  • Multiple myeloma (evidenced by large amounts of Bence Jones protein light chains excreted in the urine)
  • Nephrotic syndrome (related to disease involving renal glomeruli, which increases permeability of protein)
  • Postexercise period (related to muscle exertion)
  • Pre-eclampsia (numerous factors contribute to increased permeability of the kidneys to protein)
  • Sickle cell disease (related to increased destruction of red blood cells and excretion of hemoglobin protein)
  • Urinary tract infections (related to disease involving renal glomeruli, which increases permeability of protein)

Decreased in

    N/A

Critical findings

    N/A

Interfering factors

  • Drugs and substances that may increase urine protein levels include acetaminophen, aminosalicylic acid, amphotericin B, ampicillin, antimony compounds, antipyrine, arsenicals, ascorbic acid, bacitracin, bismuth subsalicylate, bromate, capreomycin, captopril, carbamazepine, carbarsone, carbenoxolone, carbutamide, cephaloglycin, cephaloridine, chlorpromazine, chlorpropamide, chlorthalidone, chrysarobin, colistimethate, colistin, corticosteroids, cyclosporine, demeclocycline, 1,2-diaminopropane, diatrizoic acid, dihydrotachysterol, doxycycline, enalapril, gentamicin, gold, hydrogen sulfide, iodoalphionic acid, iodopyracet, iopanoic acid, iophenoxic acid, ipodate, kanamycin, corn oil (Lipomul), lithium, mefenamic acid, melarsonyl, melarsoprol, mercury compounds, methicillin, methylbromide, mezlocillin, mitomycin, nafcillin, naphthalene, neomycin, NSAIDs, oxacillin, paraldehyde, penicillamine, penicillin, phenolphthalein, phenols, phensuximide, phosphorus, picric acid, piperacillin, plicamycin, polymyxin, probenecid, promazine, pyrazolones, quaternary ammonium compounds, radiographic agents, rifampin, sodium bicarbonate, streptokinase, sulfisoxazole, suramin, tetracyclines, thallium, thiosemicarbazones, tolbutamide, tolmetin, triethylenemelamine, and vitamin D.
  • Drugs that may decrease urine protein levels include benazepril, captopril, cyclosporine, diltiazem, enalapril, fosinopril, interferon, lisinopril, losartan, lovastatin, prednisolone, prednisone, and quinapril.
  • All urine voided for the timed collection period must be included in the collection, or else falsely decreased values may be obtained. Compare output records with volume collected to verify that all voids were included in the collection.

Nursing Implications and Procedure

Pretest

  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this test can assist in assessing the cause of protein in the urine.
  • Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
  • Obtain a history of the patient’s genitourinary and immune systems, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
  • Review the procedure with the patient. Provide a nonmetallic urinal, bedpan, or toilet-mounted collection device. Address concerns about pain and explain that there should be no discomfort during the procedure.
  • Usually a 24-hr time frame for urine collection is ordered. Inform the patient that all urine must be saved during that 24-hr period. Instruct the patient not to void directly into the laboratory collection container. Instruct the patient to avoid defecating in the collection device and to keep toilet tissue out of the collection device to prevent contamination of the specimen. Place a sign in the bathroom to remind the patient to save all urine.
  • Instruct the patient to void all urine into the collection device and then to pour the urine into the laboratory collection container. Alternatively, the specimen can be left in the collection device for a health-care staff member to add to the laboratory collection container.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Note that there are no food, fluid, or medication restrictions unless by medical direction.

Intratest

  • Potential complications: N/A
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Instruct the patient to cooperate fully and to follow directions.
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection.
  • Random Specimen (Collect in Early Morning)

  • Clean-Catch Specimen
  • Instruct the male patient to (1) thoroughly wash his hands, (2) cleanse the meatus, (3) void a small amount into the toilet, and (4) void directly into the specimen container.
  • Instruct the female patient to (1) thoroughly wash her hands; (2) cleanse the labia from front to back; (3) while keeping the labia separated, void a small amount into the toilet; and (4) without interrupting the urine stream, void directly into the specimen container.
  • Indwelling Catheter

  • Put on gloves. Empty drainage tube of urine. It may be necessary to clamp off the catheter for 15 to 30 min before specimen collection. Cleanse specimen port with antiseptic swab, and then aspirate 5 mL of urine with a 21- to 25-gauge needle and syringe. Transfer urine to a sterile container.
  • Timed Specimen

  • Obtain a clean 3-L urine specimen container, toilet-mounted collection device, and plastic bag (for transport of the specimen container). The specimen must be refrigerated or kept on ice throughout the entire collection period. If an indwelling urinary catheter is in place, the drainage bag must be kept on ice.
  • Begin the test between 6 and 8 a.m. if possible. Collect first voiding and discard. Record the time the specimen was discarded as the beginning of the timed collection period. The next morning, ask the patient to void at the same time the collection was started and add this last voiding to the container. Urinary output should be recorded throughout the collection time.
  • If an indwelling catheter is in place, replace the tubing and container system at the start of the collection time. Keep the container system on ice during the collection period, or empty the urine into a larger container periodically during the collection period; monitor to ensure continued drainage, and conclude the test the next morning at the same hour the collection was begun.
  • At the conclusion of the test, compare the quantity of urine with the urinary output record for the collection; if the specimen contains less than the recorded output, some urine may have been discarded, invalidating the test.
  • Include on the collection container’s label the amount of urine collected and test start and stop times.
  • General

  • Promptly transport the specimen to the laboratory for processing and analysis.

Post-Test

  • Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
  • Recognize anxiety related to test results. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
  • Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include amino acid screen, ACE, β2-microglobulin, biopsy bladder, biopsy bone marrow, bladder cancer markers, BUN, calcium, CBC, CT pelvis, CT renal, creatinine, cryoglobulin, culture urine, cytology urine, cystometry, cystoscopy, glucose, glycated hemoglobin, Hgb electrophoresis, IgA, IgG, IgM, IFE, IVP, lead, LAP, MRI musculoskeletal, microalbumin, osmolality, porphyrins, protein blood total and fractions, renogram, sickle cell screen, US bladder, US spleen, UA, and voiding cystourethrography.
  • Refer to the Genitourinary and Immune systems tables at the end of the book for related tests by body system.