Protein, Blood, Total and Fractions and Protein, Urine
Synonym/Acronym
TP, SPEP (fractions include albumin, alpha1-globulin, alpha2-globulin, beta-globulin, and gamma-globulin).
Rationale
Blood: To assess nutritional status related to various disease and conditions such as burns, edema, dehydration, and malabsorption. Urine: 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.
Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction. For urine studies, usually a 24-hr urine collection is ordered. As appropriate, provide the required urine collection container and specimen collection instructions.
Normal Findings
Method: Blood and Urine: Spectrophotometry for total protein, electrophoresis for protein fractions.
Blood: Total Protein
| Age | Conventional Units | SI Units (Conventional Units × 10) |
|---|
| Newborn–5 days | 3.8–6.2 g/dL | 38–62 g/L | | 1–3 yr | 5.9–7 g/dL | 59–70 g/L | | 4–6 yr | 5.9–7.8 g/dL | 59–78 g/L | | 7–9 yr | 6.2–8.1 g/dL | 62–81 g/L | | 10–19 yr | 6.3–8.6 g/dL | 63–86 g/L | | Adult | 6–8 g/dL | 60–80 g/L |
Values may be slightly decreased in older adults due to insufficient intake or the effects of medications and the presence of multiple chronic or acute diseases with or without muted symptoms. |
Blood: Protein Fractions
| Conventional Units | SI Units (Conventional Units × 10) |
|---|
| Albumin | 3.4–4.8 g/dL | 34–48 g/L | | alpha1-Globulin | 0.2–0.4 g/dL | 2–4 g/L | | alpha2-Globulin | 0.4–0.8 g/dL | 4–8 g/L | | beta-Globulin | 0.5–1 g/dL | 5–10 g/L | | gamma-Globulin | 0.6–1.2 g/dL | 6–12 g/L |
Values may be slightly decreased in older adults due to insufficient intake or the effects of medications and the presence of multiple chronic or acute diseases with or without muted symptoms. |
Normal 24-Hour Urine Volume
The ranges are very general averages and were not calculated on the basis of normal average body weights. Literature shows that the expected urinary output can be estimated by formula where the expected output is as follows:
Infants: 1–2 mL/kg/hr Children and adolescents: 0.5–1 mL/kg/hr Adults: 1 mL/kg/hr | | Newborns | 15–60 mL | | Infants | | | 3–10 days | 100–300 mL | | 11–59 days | 250–450 mL | | 2–12 mo | 400–500 mL | | Children and adolescents | | | 13 mo–4 yr | 500–700 mL | | 5–7 yr | 650–1,000 mL | | 8–14 yr | 800–1,400 mL | | Adults and older adults | 800–2,500 mL (average 1,200 mL) |
|
| 24-Hr Total Urine Protein | Conventional Units | SI Units (Conventional Units × 0.001) |
|---|
| Normal excretion | 30–150 mg/24 hr | 0.03–0.15 g/24 hr | | Proteinuria | Greater than 300 mg/24 hr | Greater than 0.3 g/24 hr |
The 24-hr urine volume is recorded and provided with the results of the protein measurement. Electrophoresis for fractionation is qualitative: No monoclonal gammopathy detected. (Urine protein electrophoresis should be ordered along with serum protein electrophoresis.) |
| Spot or Random Urine Protein/Creatinine Ratio—useful in situations where 24-hr urine collection is not feasible (e.g., urgent such as with pre-eclampsia, patients unable to reliably cooperate such as pediatric patients, etc.) |
|---|
| Age | Male | Female |
|---|
| 7–9 yr | 61–220 mg/g | 70–548 mg/g | | 10–12 yr | 59–220 mg/g | 57–334 mg/g | | 13–15 yr | 41–371 mg/g | 33–307 mg/g | | 16–17 yr | 31–242 mg/g | 36–329 mg/g | | Greater than 17 yr | 15–68 mg/g | 10–107 mg/g |
|
Study type: Blood collected in a gold-, red-, or red/gray-top tube; Urine from an unpreserved random or timed specimen collected in a clean plastic collection container; related body system: Digestive, Immune, and Urinary systems.
Protein is essential to all physiological functions. Proteins consist of amino acids, the building blocks of blood and body tissues. Protein is also required for the regulation of metabolic processes, immunity, and proper water balance. Total protein includes albumin and globulins. Albumin, the protein present in the highest concentrations, is the main transport protein in the body. Albumin also significantly affects plasma oncotic pressure, which regulates the distribution of body fluid between blood vessels, tissues, and cells.
Globulin is calculated from the following formula: Total protein - albumin = globulin
Globulins- alpha1-Globulins:
- alpha1-acidglycoprotein
- alpha1-antichymotrypsin
- alpha1-antitrypsin
- alpha1-fetoprotein
- group-specific component (vitamin D–binding protein)
- high-density lipoproteins
- inter-alpha1-trypsin inhibitor
- alpha2-Globulins:
- alpha2-macroglobulin
- ceruloplasmin
- haptoglobin
- beta-Globulins:
- beta2-microglobulin
- complement
- C-reactive protein
- fibrinogen
- hemopexin
- low-density lipoproteins
- transferrin
- very-low-density lipoproteins
- gamma-Globulins:
- immunoglobulin (Ig) A
- IgD
- IgE
- IgG
- IgM
After an acute infection or trauma, levels of many of the liver-derived proteins increase, whereas albumin level decreases; these conditions may not reflect an abnormal total protein determination.
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. Normally, proteins do not pass from the blood through the kidneys’ filtration process into the urine. The presence of protein in the urine (proteinuria) is a significant indication of kidney disease. Proteinuria is defined as greater than 300 mg/day on a 24-hr urine or 30 mg/dL on a random or spot urine.
The predominant causes of proteinuria are (1) lack of filtration due to damaged glomeruli and (2) a breakdown in the kidneys’ tubular reabsorption process. Chronic conditions such as diabetes, hypertension, and sickle cell anemia cause incremental and potentially irreversible kidney damage. Proteinuria is present in many cases of pre-eclampsia, especially those with associated hypertension. Acute conditions such as urinary tract infections and kidney stones can also damage the kidneys. Collection of 24-hr urine samples in certain urgent conditions may not be feasible (e.g., pre-eclampsia); spot urine protein/creatinine ratios are considered reliable indicators of proteinuria. Proteinuria can also be the result of extremely elevated serum protein levels, as seen with immunoglobulin-secreting malignancies such as multiple myeloma. The kappa and lambda light chain portions of the immunoglobulins, also known as Bence Jones proteins, are detected using electrophoresis techniques and are classic findings in conditions such as myeloma, Waldenström macroglobulinemia, and lymphoma.
Factors That May Alter the Results of the Study
Blood
- Drugs and other substances that may increase protein levels include amino acids (if given by IV), anabolic steroids, anticonvulsants, corticosteroids, furosemide, hormones (angiotensin, corticotropin, insulin, growth hormone, oral contraceptives, progesterone), and thyroid drugs.
- Hemolysis can falsely elevate results.
- Venous stasis can falsely elevate results; the tourniquet should not be left on the arm for longer than 60 sec.
- Drugs and other substances that may decrease protein levels include acetylsalicylic acid, ammonium ions, arginine, benzene, carvedilol, floxuridine, laxatives, mercury compounds, oral contraceptives, pyrazinamide, and rifampin.
- Values are significantly lower (5% to 10%) in recumbent patients.
Urine
- Drugs and other 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, cephaloglycin, cephaloridine, chlorpromazine, chlorpropamide, chlorthalidone, chrysarobin, colistimethate, colistin, contrast medium (iopanoic acid, ipodate sodium), corticosteroids, cyclosporine, demeclocycline, diatrizoic acid, dihydrotachysterol, doxycycline, enalapril, gentamicin, gold salts, hydrogen sulfide, iodopyracet, iophenoxic acid, kanamycin, corn oil (Lipomul), lithium, mefenamic acid, mercury compounds, methicillin, methylbromide, mezlocillin, mitomycin, nafcillin, naphthalene, neomycin, oxacillin, paraldehyde, penicillamine, penicillin, phenolphthalein, phensuximide, piperacillin, plicamycin, polymyxin, probenecid, pyrazolones, rifampin, sodium bicarbonate, streptokinase, sulfisoxazole, suramin, tetracyclines, thallium, thiosemicarbazones, tolbutamide, tolmetin, triethylenemelamine, and vitamin D.
- Drugs and other substances 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.
Before the Study: Planning and Implementation
Teaching the Patient What to Expect
- Discuss how the blood test can assist in assessing nutritional status related to disease process; discuss how the urine test can assist in assessing the cause of protein in the urine.
- Explain that a blood or urine sample is needed for the test. Information regarding urine specimen collection is presented with other general guidelines in Appendix A: Patient Preparation and Specimen Collection.
Potential Nursing Actions
- Include on the collection container’s label urine total volume, test start and stop times/dates, and any medications that may interfere with test results.
After the Study: Implementation & Evaluation Potential Nursing Actions
Treatment Considerations
- Monitor and trend TP. Compare with other LFTs (Alb, ALP, ALT, AST, TBil, DBil) to track the course of liver disease and response to treatment. If liver function is significantly damaged, PT will be prolonged and INR increased.
- Discuss how there are not always obvious symptoms of protein in the urine.
- Observable symptoms of excessive protein loss include urine appearing foamy and edema of the hands, feet, face, and abdomen.
Nutritional Considerations
- Discuss good dietary sources of complete protein (containing all eight essential amino acids) including meat, fish, eggs, and dairy products and that good sources of incomplete protein (lacking one or more of the eight essential amino acids) include grains, nuts, legumes, vegetables, and seeds.
- Discuss general symptoms of insufficient nutrition; dry skin, thin brittle nails, hair loss and thinning, hypoactive bowel sounds, fatigue, muscle wasting, decreased ability to perform activities of daily living.
Clinical Judgement
- Consider which cultural barriers impact the patient’s ability to embrace dietary changes that would improve health. Also consider ways to reinforce the necessity of following therapeutic recommendations to facilitate kidney health.
Follow-Up and Desired Outcomes
- Understands that depending on the results of this procedure, additional testing may be performed to evaluate or monitor disease progress and determine the need for a change in therapy.
- Acknowledges that information related to proteinuria can be found at Kidney and Urology Foundation of America at https://www.cdc.gov/kidneydisease/publications-resources/kidney-tests.html.