Protein electrophoresis
Protein electrophoresis is a laboratory test utilized to analyze the levels of major proteins in a patient's blood serum, urine, or cerebrospinal fluid. This test is particularly significant for screening and evaluating cancers, notably multiple myeloma, lymphoma, and chronic lymphocytic leukemia. It can also help identify various other conditions, including kidney, liver, intestinal, and immune disorders, as well as malnutrition, by detecting abnormal protein levels.
The procedure involves drawing blood, which is then processed to separate serum from blood cells. An electric current is applied to the serum, causing proteins to migrate at different rates according to their size and charge, resulting in distinct bands on an electrophoretic medium. Advances in technology, such as automated capillary electrophoresis and two-dimensional electrophoresis, have enhanced the accuracy and efficiency of this analysis.
Results from protein electrophoresis provide insights into the relative concentrations of key proteins like albumin and globulins, which can indicate various health conditions. For instance, abnormal levels of these proteins may suggest inflammation, liver disease, or the presence of certain cancers. Following the test, if results are abnormal, patients may be referred to a specialist for further evaluation and management. Overall, protein electrophoresis is a crucial tool in diagnostic medicine that aids in understanding a patient’s health status.
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Protein electrophoresis
ALSO KNOWN AS: Serum protein electrophoresis (SPEP)
DEFINITION: Protein electrophoresis is a laboratory test used to measure the amounts of major proteins in a patient’s blood serum, urine, or cerebrospinal fluid.
Cancers diagnosed: Most metastatic cancers, especially multiple myeloma, lymphoma, chronic lymphocytic leukemia
Why performed: Serum protein electrophoresis is used to screen for cancer or evaluate the extent of an existing cancer, particularly multiple myeloma. It can also be used to identify other diseases, including kidney, liver, intestinal, and immune disorders, as well as malnutrition. These disorders are associated with abnormal levels of different blood proteins, which can be detected by electrophoresis.
Patient preparation: There is no special preparation for this procedure. Patients undergo a normal fasting blood test (meaning that they cannot eat or drink for about twelve hours prior) and should tell their physicians which prescription medications they are taking.
Steps of the procedure: A physician or nurse will draw blood from a vein in the patient’s arm in an outpatient setting. The blood sample is transferred to the laboratory, where it is centrifuged to separate serum, the plasma without clotting factors, from the blood cells. Blood proteins are retained in the serum. A small amount of serum is then transferred to an electrophoretic paper or gel, such as cellular acetate or agarose, respectively. Since proteins are charged molecules and vary in size, they will migrate differentially when a current is applied to the electrophoretic field. A fluorescent agent that binds to proteins is added to the serum for illumination. The result is a gradient of separated bands, or fractions, of proteins. A laboratory specialist studies an image of the gel to determine the relative concentrations of different proteins in the blood serum.
In the twenty-first century, advances have been made that have improved protein electrophoresis. Automated capillary electrophoresis systems have made the analysis of protein mixtures more accurate. Capillary gel electrophoresis has made separating proteins easier, allowing for precise analysis. Microchip electrophoresis and two-dimensional electrophoresis have also seen significant improvements. Finally, capillary zone electrophoresis (CZE) is an alternative to protein electrophoresis. CZE is seen by many in the medical community as more accurate, sensitive, and faster.
After the procedure: A bandage is applied to the patient’s arm at the puncture site, and the patient can go home.
Risks: Protein electrophoresis does not carry risks. However, a blood draw may cause minor bleeding or bruising at the puncture site. The patient may also feel light-headed, and fainting is possible after the blood draw.
Results: The major blood proteins consist of albumin and globulins. There are four types of globulin proteins: alpha-1 globulins, alpha-2 globulins, beta globulins, and gamma globulins. Albumin makes up more than half of the proteins in the blood serum and is essential for normal tissue growth. High levels of albumin proteins result from dehydration, while low levels suggest inflammatory disease, liver disease, malnutrition, or a kidney disorder. High levels of alpha-1 globulins (alpha-1 antitrypsin, thyroid-binding globulin, and transcortin) may indicate acute inflammatory disease and malignancies, while a low level can indicate liver disease. The levels of certain alpha-2 globulins (ceruloplasmin, alpha-2 macroglobulin, and haptoglobulin) can aid in cancer diagnosis. For example, a low level of haptoglobin may indicate tumor metastasis or liver disease. Variations in other alpha-2 globulin levels may indicate inflammation, nephrotic syndrome, or hemolysis, which is the loss of hemoglobin from red blood cells. High levels of beta globulin (transferrin and beta lipoprotein) can indicate cirrhosis, hyperthyroidism, diabetes mellitus, and carcinoma in some cases, while decreased levels indicate malnutrition. High levels of gamma globulins (various antibodies) are the most indicative of cancers such as multiple myeloma, lymphocytic leukemia, or malignant lymphoma. In addition, high levels can indicate Hodgkin's disease, connective tissue disorders, and chronic or acute infections. A patient whose serum protein electrophoresis yields abnormal results will be referred to a hematologist-oncologist.
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