Serum free light chain analysis and urine immunofixation electrophoresis in patients with multiple myeloma.

Purpose: Retrospective studies have shown that immunoassays measuring free light chains (FLC) in serum are useful for diagnosis and monitoring of multiple myeloma. This study prospectively evaluates the use of FLC assays and, for the first time, investigates the relationship between serum FLC concentrations and the presence and detectability of Bence Jones (BJ) proteins in the urine.

Patients And Methods: Three hundred seventy-eight paired samples of serum and urine were tested from 82 patients during the course of their disease.