Total Protein (TP), Serum or Plasma

CPT 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

Methodology:

Colorimetric

Collection:

Separate serum or plasma from cells within four hours of collection. Complete clot formation should take place before centrifugation.  Specimens should be free of particulate matter.

Reference Range:

6.4-8.2 g/dL

Stability: 

Temperatures  Period 
Room Temperature  8 Hours 
Refrigerated (2-8 ⁰C)  72 Hours 
Frozen (≤ -20 ⁰C)  6 Months 
Protection from light is required when specimens are stored for more than 8 hours.

 

Use: 

Serum proteins aid the body in immune defense, inflammation defense, blood clotting, and transport of other substances in the blood. 

Clinical Significance: 

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).

Causes for Rejection: 

Hemolysis; improper labeling 

Interfering Substances:

Dextran 40 of 1500 mg/dL increases a TP result of 7.0 g/dL by 17%. Immunoglobulin G of 2.5 g/dL increases a TP result of 7.0 g/dL by 25%. Using  standard sample size (15 µL): Hemoglobulin (hemolysate) of 500 mg/dL increases a TP result of 3.9 g/dL by 11%. Bilirubin (unconjugated) of 20 mg/dL decreases a TP result of 3.8 g/dL by -11%. Lipemia of 600 mg/dL and above (magnitude of interference is unavailable).

For reduced sample size (10 µL): Hemoglobulin (hemolysate) of 300 mg/dL increases a TP result of 3.2 g/dL by 11%. Bilirubin (unconjugated) of 20 mg/dL decreases a TP result of 3.2 g/dL by -13%. Lipemia of 600 mg/dL and above (magnitude of interference is unavailable).