Serum Protein Electrophoresis Test (SPEP Test)

Serum Protein Electrophoresis Test

IIt is a laboratory test that is used to find out the levels of different types of proteins present in serum (the liquid portion of blood). It is also called SPEP test. Serum protein electrophoresis is a very useful aid for diagnosis of certain diseases and some cancers. This is because in these diseases and cancers, particular serum protein levels are abnormally elevated and hence can be detected by performing electrophoresis.

The most vital function of this test for which it is used very often is to find an abnormal type of protein called M protein. This protein is found in a particular type of cancer called multiple myeloma. It is a cancer of a type of white blood cell called plasma cell which are produced in bone marrow. The other important diseases detected are waldenstroms macroglobulinemia, primary amyloidosis and monoclonal gammopathy. These specific diseases are detected with the help of another test called immune fixation electrophoresis (IFE) which is an advancement over the usual serum protein electrophoresis test.

Why is Serum Protein Electrophoresis test prescribed?

The health care provider may advise this test in presence of certain symptoms (and based on clinical suspicion) such as:

• Unexplained weight loss
• Unexplained frequent fractures and/or bone pain
• Excessive weakness/fatigue
• Excessive thirst
• Frequent urination
• Constipation
• Recurrent infections
• Back pain

What are the components of SPEP test?

In serum protein electrophoresis, serum proteins are separated according to their physical properties/electric charge. The different types of proteins assessed in this procedure are:

• Serum albumin- forms the major serum protein component. It is produced by the liver. Its level decreases in malnutrition, liver disease, kidney disease, burns and pregnancy. Its level increases in dehydration.
• Alpha 1 globulin- it includes alpha1-antitrypsin, thyroid binding globulin and transcortin. Its level decreases in liver disease and alpha1-antitrypsin deficiency. Its level increases in certain cancers, inflammation and pregnancy
• Alpha2 globulin-it includes ceruloplasmin, alpha2-macroglobulin and haptoglobin. Its level increases in acute inflammation, advanced diabetes, nephrotic syndrome. Its level decreases in malnutrition and liver disease.
• Beta1 globulin and beta2 globulin-their level increase in hypothyroidism, iron deficiency anaemia, biliary cirrhosis. Their level decrease in malnutrition.
• Gamma globulin-it majorly includes immunoglobulins predominantly of IgG type. Their level increase in amyloidosis, chronic lymphocytic leukemia, multiple myeloma, Hodgkin’s disease, connective tissue disorder. Their level decrease in agammaglobulinemia and hypogammaglobulinemia

Procedure and Prerequisites

The sample for serum protein electrophoresis test is taken from blood by inserting a small needle into vein of the arm. A small amount of blood is then collected in a test tube or vial. There may be little pain due to needle prick. No particular preparation is needed for the test

Reference Range

The reference values for different types of proteins are as follow:

• albumin-3.8 to 5.0 Gms /dl
• Alpha1 globulin-0.1 to 0.3 Gms /dl
• Alpha2 globulin-0.6 to 1.0 gms/dl
• beta globulin-0.7 to1.4 gms/dl
• gamma globulin-0.7 to1.6 gms/dl

Reference values may vary from lab to lab.