Which test is used to confirm the presence of Bence-Jones proteinuria?

The confirmation of Bence-Jones proteinuria, which is characterized by the presence of free light chains of immunoglobulin in the urine, is primarily achieved through immunoelectrophoresis. This technique allows for the separation and identification of proteins based on their size and electrical charge, making it particularly suitable for detecting small proteins such as Bence-Jones proteins.

Immunoelectrophoresis works by applying an electric field to a sample of urine containing Bence-Jones proteins, which then migrate through a gel. Specific antisera are used to identify and confirm the presence of the light chains, providing a definitive diagnosis. This method is more specific and reliable in identifying these proteins than other techniques.

While urinalysis can initially suggest proteinuria, it does not specifically identify the type of protein present. Western blotting and ELISA are techniques used for protein detection and quantification, but they are not the standard methods for confirming Bence-Jones proteinuria specifically. Immunoelectrophoresis stands out as the confirmatory test in clinical practice, providing clear identification of the proteins associated with this condition.