SERUM TOTAL PROTEINS
Pre-test preparation or requirements
• Sample can be drawn at any time. No fasting or special preparation required.
• Sample should taken in plain vial.
Significance of test
Total protein measures all proteins in serum including albumin and globulin. Albumin being the major part.
The only clinical situation that causes an increase in serum albumin is acute dehydration.
A decreased albumin level, either from depressed synthesis or increased losses.
A decrease in albumin synthesis is caused by:
End-stage liver disease
Intestinal malabsorption syndromes
Albumin losses in:
Severe burns because the skin is the most important extra storage pool for albumin.
The consequence of a decrease in serum albumin is a shift of fluid from the intravascular to the interstitial space, causing intravascular volume depletion and edema formation.
Any increase or decrease in the globulin fraction should be evaluated by serum electrophoresis.
The α1 fraction of globulin is mainly of α1 antitrypsin. Decreased level of α1antitrypsin is seen in congenital α1 antitrypsin deficiency. An increase is seen in acute inflammatory disorders.
The major proteins in the α2 region include α2 macroglobulin and haptoglobin. An increase in α2macroglobulin is seen in the nephrotic syndrome as lower molecular weight proteins are lost in the urine. Haptoglobin levels increases in response to stress, infection, acute inflammation and tissue necrosis by stimulation of synthesis. Haptoglobin levels decreases in hemolytic reaction because the haptoglobin complexes with free hemoglobin to clear from the circulation.
The major β globulin is transferrin. Elevations occur in severe iron deficiency.
The most frequent abnormalities found in the γ region are a polyclonal increase or a narrow monoclonal spike.
Polyclonal increase is seen in chronic infections, connective tissue disorders, and liver disease.
Monoclonal spikes suggest multiple myeloma, Waldenstrom's macro-globulinemia, primary amyloidosis, lymphoma, or monoclonal gammopathy. Any abnormality in the γ region suggesting a monoclonal spike should be further evaluated by immunoelectrophoresis.
Hypogammaglobulinemia is a decrease in the γ component is seen in congenital immune deficiency syndromes or in association with disorders such as nephrotic syndrome, chronic lymphocytic leukemia, and corticosteroid treatment.