Where are most of the serum/plasma proteins found?
albumin, fibrinogen, lipoproteins, haptoglobin and other globulins synthesized in the liver. Immunoglobulins and hemoglobin in the adult, produced by B-Cells and rbc's respectively, are the major exceptions.
Does serum and plasma contain the same proteins?
Same proteins, with the exception of fibrinogen which is consumed in the clotting process & found in plasma.
the clear, straw yellow fluid which separates from the red blood cells after coagulation
the fluid that separates from unclotted RBCs. It is a slightly turbid (cloudy) yellow color similar to the serum.
the appearance of free hemoglobin in serum/plasma due to RBC destruction. Hemolyzed serum or plasma is unsuitable for laboratory analysis.
Total Serum Protein Reference Interval
between 6.4 and 8.3 g/dL (64-83 g/L) for an ambulatory adult.
Factors that influence total protein content of serum
individual's water balance (edema), nutritional status, hepatic function, renal function & presence of metabolic errors or diseases such as multiple myeloma. NOTE: it is the variations in the specific protein fractions that are most useful in diagnosing disease.
the increase in total protein concentration. These increases can be relative or absolute.
result of changes related to body water levels. Dehydration, causes all fractions of protein to be increased by same percentage. Dehydrated patients commonly display hyperproteinemia. Dehydration caused by decreased fluid intake or by increased water loss in diseases such as Addison's disease, diabetic acidosis or severe diarrhea.
increases are due to increased protein synthesis. Liver proteins, on balance, are rarely increased, for if one fraction increases due to disease another will decline. Immune system disorders, on the other hand, are extra-hepatic and able to significantly elevate total protein. Multiple myeloma is a malignancy resulting in overproduction of gamma globulins.
due to increased protein loss or to low protein intake. Starvation or malabsorption disorders; nephrotic syndrome where albumin is lost through damaged tubules or glomeruli; blood loss that occurs as the result of traumatic injury (water replaced more rapidly than the proteins); patients with extensive burns. Most is absolute, caused by actual loss of protein while relative conditions may be caused by excessive fluid intake or retention and manifests as edema.
Acute Phase Reactions (APRs)
plasma proteins that elevate or decline in response to inflammation. Elevation/decline frequently result of infection, myocardial infarction, tumor growth, surgery or trauma. Assumed that all APRs play a part in host defense. As some acute phase reactants rise, levels of "negative APRs", albumin, prealbumin and transferrin fall. Therefore total serum protein concentration, as a result, changes very little.