Glycosylated Bence Jones Protein with Poor Thermal Reactivity in Heat Coagulation Tests

Background We experienced a patient with multiple myeloma whose urine contained a considerable amount of Bence Jones protein (BJP), which demonstrated poor thermal reactivity in heat coagulation test. The mechanism for this phenomenon was assessed. Methods Immunoelectrophoretic analyses reveal that a band corresponding to BJP in the urine had 2,600 Dalton by reduction after glycosidase treatment, but not after sialidase treatment. In addition, the glycosidase-treated urine tested positive in heat coagulation test. Conclusions Glycosylation of the immunoglobulin light chain, which has rarely been seen, is the cause of the unexpected behavior of this patent's BJP in heat coagulation tests.