Immunoelectrophoresis - urine

Definition

Urine immunoelectrophoresis is a lab test that measures immunoglobulins in a urine sample.

Immunoglobulins are proteins that function as antibodies, which fight infection. There are various types of these proteins that fight different types of infections. Some immunoglobulins can be abnormal and may be due to cancer.

Immunoglobulins can also be measured in the blood.

Alternative Names

Immunoglobulin electrophoresis - urine; Gamma globulin electrophoresis - urine; Urine immunoglobulin electrophoresis; IEP - urine

How the Test is Performed

A clean-catch urine sample is needed. The clean-catch method is used to prevent germs from the penis or vagina from getting into a urine sample. To collect your urine, the health care provider may give you a special clean-catch kit that contains a cleansing solution and sterile wipes. Follow instructions exactly.

After you provide a urine sample, it is sent to the laboratory. There, the laboratory specialist will place the urine sample on special paper and apply an electric current. The various proteins move and form visible bands, which reveal the general amounts of each protein.

How to Prepare for the Test

Your provider may ask you to collect the first morning urine, which is the most concentrated.

If you are taking the collection from an infant, you may need extra collection bags.

How the Test will Feel

The test involves only normal urination, and there is no discomfort.

Why the Test is Performed

This test is used to measure the amounts of various immunoglobulins in urine. Most often, it is done after a large amount of protein is found in the urine.

Normal Results

Normally there is no protein, or only a small amount of protein in the urine. When there is protein in the urine, it normally consists of mainly albumin.

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

Immunoglobulin in the urine can result from:

• An abnormal buildup of proteins in tissues and organs (amyloidosis)
• Leukemia
• Blood cancer called multiple myeloma
• Kidney disorders such as IgA nephropathy or IgM nephropathy

Some people have monoclonal immunoglobulins, but do not have cancer. This is called monoclonal gammopathy of unknown significance, or MGUS.

References

Chernecky CC, Berger BJ. Protein electrophoresis – urine. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:920-923.

McPherson RA. Specific proteins. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. Philadelphia, PA: Elsevier; 2017:chap 19.