Quantitative Bence-Jones protein test

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, your health care provider may give you a special clean-catch kit that contains a cleansing solution and sterile wipes. Follow instructions exactly so that the results are accurate.

The sample is sent to the lab. There are many methods used to detect Bence-Jones proteins. One method, called immunoelectrophoresis, is the most accurate.

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

Bence-Jones proteins are a part of regular antibodies called light chains. These proteins are not normally in urine. Sometimes, when your body makes too many antibodies, the level of light chains also rises. Bence-Jones proteins are small enough to be filtered out by the kidneys. The proteins then spill into the urine.

Your provider may order this test:

• To diagnose conditions that lead to protein in the urine
• If you have a lot of protein in your urine
• If you have signs of a blood cancer called multiple myeloma

A normal result means no Bence-Jones proteins are found in your urine.

Bence-Jones proteins are rarely found in urine. If they are, it is usually associated with multiple myeloma.

An abnormal result may also be due to:

• An abnormal buildup of proteins in tissues and organs (amyloidosis)
• Blood cancer called chronic lymphocytic leukemia
• Lymph system cancer (lymphoma)
• Buildup in the blood of a protein called M-protein (monoclonal gammopathy of unknown significance; MGUS)
• Chronic renal failure

There are no risks with this test.

Immunoglobulin light chains - urine; Urine Bence-Jones protein

Gertz MA, Dispenzieri A. Amyloidosis. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 174.

Rajkumar SV, Dispenzieri A. Multiple myeloma and related disorders. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 101. 

Riley RS, McPherson RA. Basic examination of urine. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 29.

Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.