IEP - serum; Immunoglobulin electrophoresis - serum; Gammaglobulin electrophoresis; Immunoelectrophoresis - serum
This test detects the presence or absence of immunoglobulins in the blood and assess the qualitative character (polyclonal vs. monoclonal) of the immunoglobulins.
How the test is performed
Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet (an elastic band) or blood pressure cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to distend (fill with blood).
A needle is inserted into the vein, and the blood is collected in an airtight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
Infant or young child:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
Immunoelectrophoresis is a laboratory technique. It uses a combination of protein electrophoresis and an antigen-antibody interaction. Protein electrophoresis indicates immunoglobulins as a group. Immunoelectrophoresis enhances the ability to identify the specific immunoglobulins through the use of specific antibodies to the proteins of interest.
Specific lab technique: Monospecific (that is, specific for one antigen such as kappa or lambda immunoglobulin light chains) antiserum is overlaid on the zone of the electrophoretogram (the paper graph used with protein electrophoresis), which contains the unidentified protein. The presence of a precipitin band indicates that the specific protein identified by the monospecific antiserum used is present.
How to prepare for the test
Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child’s age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child’s age:
- Infant test or procedure preparation (birth to 1 year)
- Toddler test or procedure preparation (1 to 3 years)
- Preschooler test or procedure preparation (3 to 6 years)
- Schoolage test or procedure preparation (6 to 12 years)
- Adolescent test or procedure preparation (12 to 18 years)
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
This test is performed to assess the clonality (monoclonal or polyclonal) of immunoglobulins.
No monoclonal antibodies are detected.
What abnormal results mean
In some malignant disorders (that is, multiple myeloma, chronic lymphocytic leukemia) a single clone of lymphocytes produces one type of protein - a monoclonal immunoglobulin. This is identifiable as monoclonal (all the same type) by immunoelectrophoresis. Some people have monoclonal immunoglobulins, but do not have a malignant disorder.
What the risks are
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
- Multiple punctures to locate veins
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
by Brenda A. Kuper, M.D.