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.