What condition indicates the presence of Bence Jones proteins?

The presence of Bence Jones proteins is primarily associated with multiple myeloma, a type of cancer that arises from the proliferation of plasma cells in the bone marrow. In this condition, abnormal plasma cells produce excessive amounts of monoclonal immunoglobulin light chains, which can be excreted in the urine as Bence Jones proteins. Detection of these proteins in urine is a significant diagnostic marker for multiple myeloma, as they are often the first detectable markers indicating the disease and can correlate with the severity and progression of the condition.

Bence Jones proteins are typically not found in other conditions like diabetic nephropathy, post-renal proteinuria, or orthostatic proteinuria, which involve different mechanisms of proteinuria and do not involve the specific light chains produced by malignant plasma cells. Therefore, the identification of these proteins in urine serves as a strong indication of multiple myeloma, emphasizing the importance of urine analysis in diagnosing this hematological malignancy.