Total protein - common data for the parameters, principles of the analytical methods and interferences, indications for investigation, patient preparation, reference ranges, result interpretation.
Function of proteins in the human body
- Plasticity – building elements of cellular and intercellular structures (collagen, elastin, proteoglycans)
- Molecular substrate for the realization of genetic information
- Homeostasis – maintain the constancy of the internal environment (pH of blood)
- Contractility (actin and myosin in muscular cells)
- Source of energy
- Transport
- Receptors for hormones, Ig, cytokines
The total protein test measures the total amount of two classes of proteins found in the fluid portion of your blood. These are albumin and globulin. Proteins are important parts of all cells and tissues. Albumin helps prevent fluid from leaking out of blood vessels. Globulins are an important part of your immune system. The globulin in turn is made up of α1, α2, β, and γ globulins.
A blood sample is needed. Most of the time blood is drawn from a vein located on the inside of the elbow or the back of the hand
Indications for investigation: This test is often done to diagnose nutritional problems, kidney disease or liver disease.
Reference Range: 60 to 83 g/L
Principles of the analytical methods and interferences:
Protein electrophoresis: separates proteins in the blood based on their electrical charge Biuret reagent - proteins mixed with Cu2+ in alkaline solution, results show a purple mixture. more protein=darker colour (spectroscopy) Kjedhal method Refractometry
Result Interpretation:
hyperproteinaemia: Higher-than-normal levels may be due to: Chronic inflammation or infection, including HIV and hepatitis B or C, Multiple myeloma, Waldenstrom disease.
Hypoproteinaemia: Lower-than-normal levels may be due to: Agammaglobulinemia, Bleeding (haemorrhage), Burns (extensive), Glomerulonephritis, Liver disease, Malabsorption, Malnutrition, Nephrotic syndrome