Protein, Total, Serum

Protein, Total, Serum

CPT Test code: 84155

Specimen: Serum (preferred) or plasma
Volume: 1 mL
Minimum Volume: 0.5 mL
Container: Gel-barrier tube, transport tube, green-top (heparin) tube, or lavender-top (EDTA) tube
Collection: Separate serum or plasma from cells within four hours of collection.
Storage Instructions: Maintain specimen at room temperature.
Causes for Rejection: Hemolysis; improper labeling
Use: Evaluate nutritional status; investigate edema.

In the entities which follow, the diseases listed are sometimes increased or decreased as indicated, but are not always so.

Causes of high total protein: dehydration; some cases of chronic liver disease, including chronic active hepatitis and cirrhosis; neoplasms, especially myeloma; macroglobulinemia of Waldenström; tropical diseases (eg, kala-azar, leprosy, and others); granulomatous diseases, such as sarcoidosis; diseases in which total protein is sometimes high include collagen disease (eg, lupus erythematosus (SLE), and other instances of chronic infection/inflammation).

Causes of low total protein: pregnancy; intravenous fluids; cirrhosis or other liver disease, including chronic alcoholism; prolonged immobilization; heart failure; nephrotic syndromes; glomerulonephritis; neoplasia; protein losing enteropathies; Crohn’s disease and chronic ulcerative colitis; starvation, malabsorption or malnutrition; hyperthyroidism; burns; severe skin disease; and other chronic diseases.

Very low total protein (<4 g/dL) and low albumin cause edema (eg, the nephrotic syndromes).

Limitations: Clinical interpretation is greatly enhanced by examination of the fractions composing total protein, when such separation is clinically indicated (ie, serum protein electrophoresis, quantitative immunodiffusion or other methods for IgG, IgA, IgM, immunofixation, immunoelectrophoresis).
Additional Information: Total protein and albumin normally decrease by 5% to 10% upon recumbency, as in hospitalization. Drug effects are summarized.1
Footnotes: 1. Herbeth B, Diemert MC, Galli A, “Total Proteins,” Drug Effects on Laboratory Test Results Analytical Interferences and Pharmacological Effects, Siest G, Galteau MM, eds, Littleton, MA: PSG Publishing Co, Inc, 1988, 375-90.