Electrophoresis is used to identify the presence or absence of abnormal proteins and to identify when different groups of proteins are increased or decreased in serum or urine. It is frequently used to detect and identify monoclonal proteins (an excessive production of one specific immunoglobulin). Protein and immunofixation electrophoresis are used to help detect, diagnose, and monitor the course and treatment of conditions associated with these abnormal proteins, including multiple myeloma and a few related diseases.

Protein is usually excreted in the urine in very small amounts. When it is present in moderate to large amounts, it often indicates a problem with the kidneys. The primary reason protein and immunofixation electrophoresis are requested on urine is to look for monoclonal protein production. This protein may show up in both the serum and urine, or it may only be seen in the urine. An example of this is Bence Jones protein, which is the free light chain component of antibodies (normally, antibodies are composed of four parts, two identical heavy chains and two identical light chains. Sometimes, in multiple myeloma, only one or the other is produced, or it may be produced in excess.) The small size of Bence Jones protein allows it to pass through the kidneys and enter the urine.

Urine protein electrophoresis may also be used to help diagnose the cause and estimate the severity of protein excretion due to kidney damage or disease. This damage or disease may be due to diabetes, chronic inflammation, an autoimmune condition, or a malignancy. Electrophoresis is not usually necessary to assess the loss of small to moderate amounts of protein due to temporary conditions, such as a urinary tract infection or an acute inflammation.

Protein electrophoresis may be requested when a doctor is investigating symptoms that suggest multiple myeloma, such as bone pain, anaemia, tiredness, unexplained fractures, and recurrent infections. It may also be used as a follow-up to other laboratory tests, such as an abnormal total protein and/or albumin level, elevated urine protein levels, elevated calcium levels, and low white or red blood cell counts. Immunofixation electrophoresis is usually ordered when the protein electrophoresis test shows the presence of an abnormal protein band that may be an immunoglobulin.

Electrophoresis tests are most frequently requested when a doctor suspects a disease or condition that causes a monoclonal protein to be produced. Once a disease or condition has been diagnosed, electrophoresis may be used at regular intervals to monitor the course of the disease and the effectiveness of treatment. As disease progresses, the amount of protein goes up; with treatment, it goes down. Monoclonal protein production may be due to a malignant disease, such as multiple myeloma, but it may also be due to a monoclonal gammopathy of undetermined significance (MGUS). Most patients with MGUS have no symptoms, but they must continue to be monitored regularly as some may develop multiple myeloma after a number of years.

Serum protein electrophoresis may also be used when symptoms suggest an inflammatory condition, an autoimmune disease, an acute or chronic infection, a kidney or liver disorder, or a protein-losing condition, even if the total protein and/or albumin concentrations are apparently normal. Urine protein electrophoresis may be used when there is protein detected in the urine or when the doctor suspects a monoclonal protein may be present.

Protein and immunofixation electrophoresis tests give your doctor a rough estimate of how much of each protein is present. The value of protein electrophoresis lies in the proportions of proteins and in the patterns they create on the electrophoresis graph. The value of immunofixation electrophoresis is in the identification of the presence of a particular type of immunoglobulin.

For example, certain conditions or diseases may be associated with decreases or increases in various serum proteins, as reflected below:

Albumin

• Decreased with malnutrition and malabsorption, pregnancy, kidney disease (especially nephrotic syndrome), liver disease, inflammatory conditions, and protein-losing syndromes
• Increased with dehydration

Alpha1 globulin

• Decreased in congenital emphysaema (a1-antitrypsin deficiency, a rare genetic disease) or severe liver disease
• Increased in acute or chronic inflammatory diseases

Alpha2 globulin

• Decreased with hyperthyroidism or severe liver disease, haemolysis (red blood cell breakage)
• Increased with kidney disease (nephrotic syndrome), acute or chronic inflammatory disease

Beta globulin

• Decreased with malnutrition, cirrhosis
• Increased with hypercholesterolaemia, iron deficiency anaemia, some cases of multiple myeloma or MGUS

Gamma globulin

• Decreased variety of genetic immune disorders, and in secondary immune deficiency
• Increased Polyclonal: chronic inflammatory disease, rheumatoid arthritis, systemic lupus erythematosus, cirrhosis, chronic liver disease, acute and chronic infection, recent immunization. Monoclonal: Waldenstrom's macroglobulinaemia, multiple myeloma, monoclonal gammopathies of undetermined significance (MGUS)

Immunisations within the previous six months can increase immunoglobulins as can drugs such as phenytoin (Dilantin), procainamide, oral contraceptives, methadone, and therapeutic gamma globulin.

Aspirin, bicarbonates, chlorpromazine (Thorazine), corticosteroids, and neomycin can affect protein electrophoresis results.