Bence-jones protein

Bence-Jones protein is a monoclonal globulin protein or immunoglobulin light chain found in the urine, with a molecular weight of 22-24 kDa. Detection of Bence-Jones protein may be suggestive of multiple myeloma or Waldenström's macroglobulinemia.

History

The Bence-Jones protein was described by the English physician Henry Bence Jones in 1847. Bence Jones discovered the protein after examining the urine of a patient suffering from what would later be recognized as multiple myeloma.

Biochemistry

Bence-Jones proteins are produced by neoplastic plasma cells. They are composed of immunoglobulin light chains, either kappa (κ) or lambda (λ), but not both. The proteins are small enough to pass through the glomerulus of the kidney, where they can be reabsorbed by the renal tubules.

Clinical significance

The presence of Bence-Jones proteins is a diagnostic marker of several diseases, including:

• Multiple myeloma: This is a cancer of plasma cells, which can lead to an overproduction of monoclonal light chains, some of which can be excreted in the urine as Bence-Jones proteins.
• Waldenström's macroglobulinemia: This is a type of non-Hodgkin lymphoma in which cancer cells make large amounts of an abnormal protein (macroglobulin).
• Light chain deposition disease: This is a rare condition characterized by the deposition of monoclonal light chains in various organs, leading to organ dysfunction.

Detection

Bence-Jones proteins are detected in the urine using protein electrophoresis and immunofixation. The urine is typically collected over a 24-hour period for this test.

Treatment

Treatment of conditions associated with Bence-Jones proteinuria involves addressing the underlying disease, such as chemotherapy for multiple myeloma.

See also

• Monoclonal gammopathy of undetermined significance
• Monoclonal band