Bence Jones proteinuria involves urinary excretion of light chains from which type(s) of light chains?

Bence Jones proteinuria involves urinary excretion of light chains from which type(s) of light chains?

• A. Kappa only
• B. Lambda only
• C. Both kappa and lambda
• D. Either kappa or lambda

Answer: (D)

Bence Jones proteins are free immunoglobulin light chains that are small enough to pass through the kidney filter and appear in urine. They arise when a plasma cell clone overproduces light chains without the heavy chains, so these free light chains are shed into the urine. The type of light chain produced by the abnormal clone determines what shows up in the urine, and that can be either kappa or lambda. In other words, there isn’t a fixed restriction to one type; the excreted free light chains can be of either type depending on the clone, which is why “either kappa or lambda” best captures the concept.

Bence Jones proteins are free immunoglobulin light chains that are small enough to pass through the kidney filter and appear in urine. They arise when a plasma cell clone overproduces light chains without the heavy chains, so these free light chains are shed into the urine. The type of light chain produced by the abnormal clone determines what shows up in the urine, and that can be either kappa or lambda. In other words, there isn’t a fixed restriction to one type; the excreted free light chains can be of either type depending on the clone, which is why “either kappa or lambda” best captures the concept.