Human serum contains plenty of proteins. They perform many functions. The most simple protein in serum is albumin. Apart from albumin serum contains globulin and fibrinogen. Measuring of serum proteins includes measuring of total proteins, measuring of albumin, globulin and fibrinogen levels and measuring of albumin globulin ration.
All serum globulins are classified according to protein electrophoresis into four categories: alpha 1 globulins, alpha 2 globulins, beta globulins and gamma globulins. One particular group of gamma globulins is immunoglobulins. Their primary function is to act as antibodies. Each of these globulins can be easily measured and if there is a certain medical condition their level will change and either increase or decrease. Mature B lymphocytes (plasma cells) produce antibodies and the liver is in charge with production of majority of other proteins in the alpha and beta fraction.
Changes in Globulin Levels
Normal range of globulins is 2.3-3.5 gm/dL. Alpha globulin range is 0.2-0.3 g/L and optimal beta globulin range is 0.7-1.0 g/L. The level of globulins can increase or fall below the optimal range.
High globulin levels are usually associated with chronic inflammatory diseases such as tuberculosis and syphilis. Furthermore, the level of globulins is commonly elevated in multiple myeloma, carcinoid syndrome, leukemia and Waldenstrom's macroglobulinemia. Autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis and many more are always accompanied by elevated levels of globulins. High levels of globulins also occur in different liver and kidney disorders and are also a characteristic of chronic infections caused by parasites, viruses or bacteria.
On the other hand, low globulin levels may point to the presence of hepatic and kidney dysfunction, various neoplasms, acute hemolytic anemia, hypogammaglobulinemia or agammaglobulinemia.
Optimal albumin/globulin range is 1.7-2.2 and ratio 2:1. In some medical conditions this ration can be impaired and according to the change the doctor may assume what disease a patients may be suffering from. For example, the decreased albumin/globulin ratio points to the presence of liver dysfunction. On the other hand, increased albumin/globulin ratio is a characteristic of high protein and low carbohydrate diet, hypothyroidism, hypogammaglobulinemia and glucocorticoid excess.
General increase of protein levels can be caused by certain medications such as anabolic steroids, androgens, growth hormone, insulin and progesterone. On the other side, estrogen, medications that cause liver toxicity and oral contraceptives are responsible for general decrease in protein levels. It is essential to establish the exact cause of all the previously mentioned changes and treat patient accordingly. Even once the treatment has started regular testing of serum proteins points to the success or failure of the treatment.