Correlation of Serum Immunoglobulin Free Light Chain Quantification with Urinary Bence Jones Protein in Light Chain Myeloma

Abstract

Multiple myeloma is a malignant plasma cell dyscrasia characterized by bone marrow plasmacytosis ( 1). Malignant plasma cells produce an abnormal monoclonal immunoglobulin, the laboratory hallmark of the disease process, as well as cytokines, which stimulate cells of the bone marrow microenvironment ( 2)( 3). The neoplastic clone and its products cause the dysfunction of several organs, including bone pain or fractures, renal failure, anemia, susceptibility to infection, hyperviscosity, and hypercalcemia ( 1). However, the most characteristic feature of multiple myeloma and other monoclonal gammopathies is the presence of a serum and/or urinary monoclonal (M) component on immunofixation ( 4). Approximately two-thirds of patients with a serum M component also have Bence Jones proteins (BJPs) in the urine. In almost 20% of myelomas, only immunoglobulin light chains are present in the serum and/or urine and are often designated as light chain multiple myeloma (LCMM).